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Open Access Article
1 - Synoptic Analysis of the Nature of Sudan Low Pressure Systems (Case Study: December 2001 Storm)
عباس Mofidi آذر ZarrinIn order to investigate some synoptic aspects of Sudan low systems such asupper and lower level tropospheric circulation pattern and moisture source and theiradvection way, the synoptic pattern on the occurrence time of December 2001 stormover Iran has been noticed. The MoreIn order to investigate some synoptic aspects of Sudan low systems such asupper and lower level tropospheric circulation pattern and moisture source and theiradvection way, the synoptic pattern on the occurrence time of December 2001 stormover Iran has been noticed. Therefore the maps of surface, 500, 200, 50hpa levelsbefore and after storm were studied. In order to understand the situation of subtropicaljet stream and how it strengthens, maps of zonal wind component and velocitypotential (x) of 200hpa level have investigated. Also, satellite images of cloud form ofstorm have been studied.The results showed that although like previous studies, there was low cycle indexand existence of a ridge in mid-troposphere over the west Mediterranean and a deeptrough over the east Mediterranean had important role on the formation and evolutionof Sudan low; but the main role belonged to the stretching of polar vortex in lowerstratosphere as the main source of vorticity for abnormal circulation and strengtheningof Hadley cell and Subtropical jet stream over Mediterranean and north of Africa.The results indicated that the suitable position of Subtropical jet stream core overMiddle East associated with the settlement and strengthening of a ridge in middle andlower troposphere over the Arabian Sea are necessary for the evolution and developingof Sudan lows.However, the position and speed of subtropical jet stream core over the MiddleEast and it’s axis direction in the upper troposphere control both the mid-troposphericcirculation pattern and the tracks of incoming Sudan lows to Iran.The consequences indicated that settlements and strengthening of ridge/high over theArabian Sea, while making a set positive feedback and subsequently intensify Hadleycell and strengthening subtropical jet stream over Red Sea region, lend to directtransportation of moisture from the Arabian Sea into Sudan lows.Moreover, it was found that the main sources of moisture of Sudan systems aretropical Eastern Africa and southwest sector of Arabian Sea which strengthening whenthey pass over the Read Sea and Persian Gulf. Manuscript profile -
Open Access Article
2 - Estimating Flood potential of Zilaki and Firehrud drainage basins by emphasize on Geomorphologic characters by using SCS method
Mohammad reza Sarvati Ardavan BehzadFlood is amongphenomenon which bring about considerable damage each year.This has been attractedgreatly by hydrologists. The factors such as physiography,geomorphology and human factors can accelerate this phenomenon in basins. Forusing water source, flood management, d MoreFlood is amongphenomenon which bring about considerable damage each year.This has been attractedgreatly by hydrologists. The factors such as physiography,geomorphology and human factors can accelerate this phenomenon in basins. Forusing water source, flood management, damming, watershed management and themost basic hydrologic studies, peak discharge is important, so accuracy of studies andthe safeties’ level of the hydraulic structures and establishments are independent to it.In this research potential flood Zilaki and Firehrud drainage basins were studied byusing of SCS method and finally were compared together. So BasinHydrographdimensions calculated by using of 24 hour rainfall, time of concentration, CurveNumber, rainfall excess, time to peak and peak discharge.Then was designHydrograph for basins in 2,5,10,25,50,100 period time Results show, because ofphysiography of Firehrud basin, It has more ability for making flood than Zilaki basin. Manuscript profile -
Open Access Article
3 - Heavy rain of southern Khorasan
Mohammad Golkar Hossein MohammadiInvestigating the statistical and synoptical condition of a climate of an area requires statisticsthat have accrued daily and really. Some of frequency occurrence of phenomena on should betaken on to consideration. Maybe, in near past, the condition of upper atmosphere MoreInvestigating the statistical and synoptical condition of a climate of an area requires statisticsthat have accrued daily and really. Some of frequency occurrence of phenomena on should betaken on to consideration. Maybe, in near past, the condition of upper atmosphere was notconsidered and only the surface conditions wave analysed statistically. But today investigatorscan study atmospherically phenomenon in global earth and systematically and identity theclimate pattern with applying various technics and specialized software and remote sensing.Rains is considered to be the most Irregular climate element of sub arid areas. Specially, theunique condition of its case and also heavy rain that usually leads to flood, should be studiedand regarded in environmental programming. Investigating the condition of raining, inparticular heavy rain in southern Khorasan, making use of statistical and synoptically patternsalong with surface map and 500 hp surface in cooperation is a feature of this research Hope,in future, these kinds of practical research by researches in this field. Becomes of more notice. Manuscript profile -
Open Access Article
4 - The Role of Pressure Patterns on the Precipitation of the South Coast of Caspian Sea
بهلول Alijani حسین Mohammadi آتوسا BigdeliIn order to understand the role of pressure systems on the precipitation of the Caspian coastal lands, daily precipitation data of the weather stations of the area were obtained from the Meteorological Organization of Islamic Republic of Iran for the period 1986-2003. U MoreIn order to understand the role of pressure systems on the precipitation of the Caspian coastal lands, daily precipitation data of the weather stations of the area were obtained from the Meteorological Organization of Islamic Republic of Iran for the period 1986-2003. Using Cluster Analysis the study area was divided into three distinct regions on the basis station’s precipitation variables. In each region the daily rainfall runs of 2 days length and more were determined. For each rain run a representative run was selected. For each of these selected runs the weather maps of surface and 500 hPa levels were analyzed. On the basis of this analysis the main and dominant pressure patterns of the rain days were defined. The results of the study showed that the western migratory high pressure systems are the main cause of the coastal areas precipitation. This study did not find any significant role for the ever accepted Siberian High pressure in the area’s precipitation. Manuscript profile -
Open Access Article
5 - Evaluation of different interpolation methods on daily rainfall estimation, Case study: Fars Province
علی اکبر Matkan علیرضا Shakiba آزاده YazdaniRainfall is one of the most important natural sources of water used by mankind foragricultural and industrial applications. Because of the difficulty of rainfall monitoring,which has high spatial and temporal variability, our knowledge of both the its synopticand climat MoreRainfall is one of the most important natural sources of water used by mankind foragricultural and industrial applications. Because of the difficulty of rainfall monitoring,which has high spatial and temporal variability, our knowledge of both the its synopticand climatological distribution over most of the country is not well known.Climatological investigations in Iran lack adequate meteorological observations tounderstand and interpret diverse climatic features. In the country as a whole, theground observation network is not dense enough to provide the detailed informationrequired, especially in rugged regions. Combined with this is the problem of pooraccessibility to the mountainous regions, which has resulted in the areal distribution ofrainfall being poorly known. In addition, the data collected by the existingmeteorological stations, with a few exceptions, are mostly discontinuous, nonhomogenousand short period observations. Such limited data sets, make it difficult toboth accurately delimit different climatic regimes across the country and identifysignificant departures from normal conditions, whereas many climatologicalapplications and investigations should ideally be based on the data collected at givenpoints over long periods and should have a good spatial and temporal coverage.Perhaps the most urgent problem facing rainfall measurement at the present time isdata collection - one of the most costly areas in meteorology and hydrology.In this paper, the central aim is to investigate the potential of GeographicalInformation System for monitoring Fars province’s rainfall with special reference toKriging and IDW (Inverse Distance Weighting), to describe pre-processingapproaches, including relative calibration, and to examine various techniques for bothrainfall monitoring.Analyses of the GIS techniques provided very useful information on both thespatial and temporal distributions of rainfall over regional space, although datacollected by Kriging technique showed more accurate than IDW technique. In order toexplore the appropriate method, the accuracy of the obtained results from differentmethods using RMS was examined. The results showed that among different usedkriging methods, the circular and exponential ordinary had lowest error. Manuscript profile -
Open Access Article
6 - Synoptic analysis of heavy rainfall in November 21, 2011 in Kohkilooyeh and BoyerAhmad (Likak)
Majid Montazeri Mohammad Hassan Nami Hamideh DalaeiHeavy rainfall and its direct and indirect effects on human’s lives and activities not onlyjustify the attention to the peripheral phenomenon but also provide the way to predict theirfuture occurrence.In thisstudy, after selectin gcriteria for Iran’s heavy r MoreHeavy rainfall and its direct and indirect effects on human’s lives and activities not onlyjustify the attention to the peripheral phenomenon but also provide the way to predict theirfuture occurrence.In thisstudy, after selectin gcriteria for Iran’s heavy rainfallin theSouthWest, theperipheralto circulation approach was used and the synoptic conditions at thetime of the event(21November2011) was evaluated. Results show that the progression ofSudan low pressure from the South and the European high pressure from the North and thecollision of the setwohot and coldsystems have made the mass in West and SouthWest of thecountry. In addition,in the middle level of atmosphere deepening of the Mediterraneanlanding area and its East- toward movement on the same day has located the study area in theEast Region of the landing are a which is the positive volubility area and the created spin hasmoved to the East. Therefore, Due to the severe the rmalinstability and gradient this led torising air in the region.Highhumidity has also contributed to instability and has providedconditions for heavy rainfallin the region more than before Also, one of the other factorsaffecting the heavy rainfallin the study area is that he subtropical river windspeed core haslocated on the Red Sea andin the north of Arabia Manuscript profile -
Open Access Article
7 - Coordinatin of subtropical-pressure centers in flood-rains of the south and south-easthern Iran. Case study: The rainfall of july 1976
محمد SalighehIran's southern half's climatic have especially features, is its summery rainfalls amongwhich the long–term rain of July 1976 has had a unique specialty as studied till now.In this period, there was coordination between the atmospheric cycles of low latitudes(seas MoreIran's southern half's climatic have especially features, is its summery rainfalls amongwhich the long–term rain of July 1976 has had a unique specialty as studied till now.In this period, there was coordination between the atmospheric cycles of low latitudes(seasonal spring) and mid latitudes (tropic adjoined-high pressure recycling).Thepresent study shows that the coordination of these pressure systems resulted in stringthing and intensifying the moisture penetrate from eastern side towards the site ofstudy. The coordination between these two systems in the south of Himalayas createda sort of convergency, therefore eastern and western flows of polar edge of seasonalcell have moved with higher speed. This velocity increasing make the system able tosend more moisture to Iran's south and southern east region. Moreover, the rainfallneeds elevating factors. These factor are created at a time when elevating conditionsare provided by atmosphere middle levels. Researches shows that when tropicaladjoined-high pressures transfer to higher levels, the opportunity for local sweepingselevating, will increase and precipitation will occur. Manuscript profile -
Open Access Article
8 - Modeling rainfall event characteristics using D-vine copulas
مریم شفائی احمد فاخری فرد یعقوب دین پژوه رسول میرعباسیInvestigation of precipitation characteristics is necessitate in understanding and predicting phenomena of precipitation such as runoff and flood. Therefore in this study, dependence among the main characteristics of a rainfall event (i.e., rainfall depth R, maximum rai MoreInvestigation of precipitation characteristics is necessitate in understanding and predicting phenomena of precipitation such as runoff and flood. Therefore in this study, dependence among the main characteristics of a rainfall event (i.e., rainfall depth R, maximum rainfall depth M, wet period L, and dry period D) were modeled using D-vine structure. Firstly, different multivariate probability distributions were built, making all the permutations of the conditioning variables and then Archimedean and Elliptic copulas were used for fitting each pair-copula. The best copula family was selected for fitting on each pair-copula according to different criteria. In the next stage, M-R-D-L structure, i.e., with D conditioned by L, R by D and L, and M by R, D, and L, was known as the most suitable structure considering to AIC and BIC criteria. Finally, rainfall event characteristics were simulated using the selected structure. In order to evaluation of simulation accuracy of proposed model, the main statistics of simulated variables were compared with those of observed variables. The results showed that the majority of simulated statistics have good accordance with observed statistics. Manuscript profile -
Open Access Article
9 - Investigating effective parameters of surface flow and water resources spatial zoning in central Zagross, Iran
Nasser Shamskia Hossein Sedghi Mehrdad EsfandyariVarious parameters, such as rainfall, region height, evaporation rate, temperature, climate factors, drainage, topography and geology of the basin effect runoff in watersheds. Due to the interrelation of some of the mentioned parameters, their quality and effect on runo MoreVarious parameters, such as rainfall, region height, evaporation rate, temperature, climate factors, drainage, topography and geology of the basin effect runoff in watersheds. Due to the interrelation of some of the mentioned parameters, their quality and effect on runoff may be different for each region. This paper presents a statistic assessment of the parameters that are effective on runoff and spatial zoning of surface water resources in central Zagross, west of Iran. The results showed a relationship between logarithmic distribution of surface runoff, and temperature and height variables with a 0.795 - 0.851 R2 coefficient of determination, applying statistical analysis and multi-variable regression method for the parameters. Considering 80 selected stations of the studying area with a correlation of 0.923, the runoff distribution in the form of discharge logarithm related to rain logarithm and height variable with confidence level of 95% showed meaningful and acceptable relation .The zoning plan was prepared through ArcGIS software on the basis of weighting effect index of each variable. The analysis of factors which affect runoff formation, and also analysis of the effect of the mentioned variables on preparing zoning plan showed tremendous movement of potentially appropriate water resources regions from south towards north and east of the studying area. Furthermore, there was approximate correspondence between hydrological parameters and determination of suitable water resources location, and statistic multi-variable regression analysis, logistic and weighting index determination of variables methods. Manuscript profile -
Open Access Article
10 - Climate change impact assessment on extreme daily rainfalls in Kermanshah
Mojtaba Heidari Mohammad Reza KhazaeiOne of the potential impacts of climate change is the change on extreme rainfalls frequency and magnitude. For active adaptation strategy, it is required to assess the impacts of climate change on heavy rainfalls. Many downscaling methods have been developed, however mo MoreOne of the potential impacts of climate change is the change on extreme rainfalls frequency and magnitude. For active adaptation strategy, it is required to assess the impacts of climate change on heavy rainfalls. Many downscaling methods have been developed, however most of them are not adequate for assessing climate change impact on extreme rainfalls. Among them, the NSRP rainfall model, which is generally ignored in previous studies, have considerable capabilities for climate change impact assessment on extreme rainfalls. In this paper, capability of the NSRP for daily rainfall series generation and climate change impact assessment on extreme rainfalls in Kermanshah is evaluated. The results indicated that NSRP can realistically simulate daily rainfall series containing extreme rainfalls; and can be used for climate change impact assessment on extreme rainfalls. Using the model, 100 series of daily rainfall of length 30 years were generated under each of the future A2, B1 and A1B scenarios from the CGCM3 model. Based on the results, magnitude of annual maximum rainfall of durations of one to five days will increase in future. Seasonal cycles of monthly means and accordance of extreme rainfalls will change. Long-term average of rainfall will decrease while extreme rainfall magnitude will increase. So it can be concluded that change in rainfall averages in monthly or yearly timescales cannot provide credit information about change in rainfall extremes. Respect to the results, for the future plans which are impressible of heavy rainfalls, the climate change impacts on heavy rainfalls should be considered. Manuscript profile -
Open Access Article
11 - Evaluation of wavelet – least square support vector machine hybrid model to rainfall time series spatiotemporal disaggregation
nima farboudfam Vahid Nourani babak aminnejadThe need to simulate rainfall time series at different scales for engineering purposes on the one hand and lack of recording such parameters in small scales because of administrative and economic problems, on the other hand, disaggregation of rainfall time series to the MoreThe need to simulate rainfall time series at different scales for engineering purposes on the one hand and lack of recording such parameters in small scales because of administrative and economic problems, on the other hand, disaggregation of rainfall time series to the desired scale is an essential topic. In this study, for disaggregating the Tabriz and Sahand rain gauges time series, according to nonlinear characteristics of time scales, wavelet- Least Square Support Vector Machine (WLSSVM) hybrid model is proposed and daily data of four rain gauges and monthly data of six rain gauges from Urmia Lake Basin for ten years were decomposed with wavelet transform and then by using mutual information and correlation coefficient criteria, the subseries were ranked and superior subseries were used as input data of Least Square Support Vector Machine (LSSVM) model for disaggregating the Tabriz and Sahand rain gauges monthly rainfall time series to the daily time series. Results obtained from the WLSSVM disaggregation model were compared with the results of LSSVM and traditional multiple linear regression models. The results of WLSSVM model to LSSVM and multiple linear regression models at validation stage in the optimized case for Tabriz rain gauge were increased 10% and 37.5% and in the optimized case for Sahand rain gauge were increased 24.5% and 46.7% respectively. It was concluded that hybrid WLSSVM model has a higher accuracy than two other methods and can be considered as an accurate disaggregation model to disaggregate the rainfall time series. Manuscript profile -
Open Access Article
12 - Comparison and Assessment of Light Vehicles Damages Based on Stability Theories in Floodwater(Case Study: Shiraz Flood)
Reyhaneh Golmohammadi Alireza ShokoohiIntroduction: Evaluation of damages caused by flash floods in urban areas is one of the most important concerns after their occurrence. Like other urban elements, vehicles suffer damage that should be considered for managing urban floods. The damage values in most car MoreIntroduction: Evaluation of damages caused by flash floods in urban areas is one of the most important concerns after their occurrence. Like other urban elements, vehicles suffer damage that should be considered for managing urban floods. The damage values in most car damage models in flood are presented with the assumption of their stability and purely in terms of depth, while the flood velocity as flood important variable is also effective on the severity of damages. In the present research, while evaluating the eight theories presented in the Australian Rainfall and Runoff Guideline (AR&R), an attempt is made to provide the best theory to provide a simple and accurate algorithm for determining the damage to sedan vehicles in flood as a function of depth and velocity.Methods: To achieve the goal of this research, the formulas and diagrams of the stability limit of eight theories presented in AR&R were evaluated and after deleting one of the theories and modifying the Melbourne Water presented in 1996 and DPW presented in 1986 formulas, the stability map of the sedan cars in Darwaze Quran flood on March 25, 2019 in Shiraz was produced for seven theories proposed in this guideline. Subsequently, by combining the stability limits of each theory with the HAZUS-MH depth-damage diagram and zoning below the stability limit diagram as stable areas, the risk map algorithm for stable sedan vehicles was provided separately for each theory. In the following, the risk map in the adjacent parking area of the water pool upstream of the Quran Gate of Shiraz for each theory and, with their help, the total damage for the Pride_131 was calculated as a common vehicle in Iran. Finally, the measures of maximum damage, as well as the total damages were obtained from each one.Results: One of the main and most important results of this research is providing an algorithm for determining the damage of the sedan vehicles in a certain range of depth and speed for each of the theories proposed in AR&R, which were used for producing the risk map. In addition, the total damages for the Pride-131 as an index car were calculated by the proposed algorithms. The minimum damage was obtained by using AR&R (1987) theory algorithm equal to 10 billion and 265 million toman and the maximum amount of damage was obtained by using achieved by using AR&R (2011) theory algorithm equal to 14 billion and 32 million toman.Conclusion: It was found that the use of the depth of flood as a hydrostatic index, which is now the criterion for calculating car damage, is not accurate enough and it is better to use velocity and depth composition as a hydrodynamic index for this purpose. At the same time, it was proved that among the other theories, the relation and the final limit of stability presented in the AR&R (2011) theory to provide a model for determining the damage to small and light vehicles in the flood as a function of depth and velocity has better and more reliable results. It is worth noting in order to achieve the more accurate damage amounts of vehicles in flood, more theoretical and experimental studies considering different types of vehicles are essential. Manuscript profile -
Open Access Article
13 - Evaluation of the impact of climate change on extreme flows in Kan watershed
Baharak Motamedvaziri mehdi ahmadi Hasan Ahmadi Abolfazl Moeini Gholam Reza ZehtabianClimate change is one of the major challenges affecting the natural ecosystems and various aspects of human life. The effects of global warming on the hydrology and water cycle in nature are very serious, and the quantitative recognition of these effects creates more re MoreClimate change is one of the major challenges affecting the natural ecosystems and various aspects of human life. The effects of global warming on the hydrology and water cycle in nature are very serious, and the quantitative recognition of these effects creates more readiness to deal with its consequences. In the present study, the 2010-2100 periods is predicted based on SDSM and ASD. Finally, the effect of climate change on the hydrological conditions in the Kan watershed is simulated using the ANN and IHACRES. The results of the study, while confirming the efficiency of both SDSM and ASD models in climate simulations and ANN and IHACRES in hydrological simulation, showed that the increase in precipitation (2-27%) and temperature (0.3- 4/4 C) is probable in future climate conditions for the 2010-2100 periods. Runoff changes in the upcoming period (2010-2039) show an increase (5- 36 %) in the scenario of RCPs and a decrease (32- 41%) in scenario A2. The high flow value in the upcoming period is increased, and the low flow decrease. Most changes were observed in spring. The results of research, while highlighting the importance of effects of climate change, make it essential to apply them for proper management in order to adapt to climate change in the future policies of the Kan watershed management. Manuscript profile -
Open Access Article
14 - Comparison of MIKE NAM and AWBM models performance in simulation of daily runoff in Gokbad Catchment in Hamedan province
Yasamin Sajadi Bami Jahangir Porhemmat Hossein Sedghi Navid JalalkamaliApart from the understanding of the impact of land use and climate changes on the water cycle and hydrology regime, hydrological models are effective tools for designing and managing water resources. Currently, many hydrological models have been developed to simulate th MoreApart from the understanding of the impact of land use and climate changes on the water cycle and hydrology regime, hydrological models are effective tools for designing and managing water resources. Currently, many hydrological models have been developed to simulate the basin, though choosing the right model is a challenge. To this end, a correct understanding of the model, its advantages, and limitations is necessary. In this regard, several studies have been conducted to evaluate the hydrological models performance in different regions and conditions. In the present study, the performance of two integrated hydrological and conceptual rainfall-runoff models of AWBM and MIKE NAM in the simulation of the average daily runoff in Gonbad Hamedan basin was investigated. Although both models are lumped models for rainfall-runoff process, the MIKE NAM model has a more complex structure compared to the AWBM. In addition to considering the initial conditions, MIKE NAM model is also capable of simulating snowmelt. The results of the runoff simulation during the calibration and validation periods were evaluated using two statistical indicators of the Nash-Sutcliffe efficiency (NSE) and percent bias (PBIAS). The NSE and PBIAS during the calibration and validation periods for the MIKE NAM model were 0.8, 6.3 and 0.71, -4.2; and 0.6, 14.33 and 0.55, -9.2 for AWBM model, respectively. The results showed that MIKE NAM model has a better performance in simulating daily runoff in Gonbad Moarref basin compared to the AWBM model. Manuscript profile -
Open Access Article
15 - Simulation of Long-Term Rainfall in Babolsar City by Using Optimized Wavelet-Extreme Learning Machine
hamed karimi mohammad ali izadbakhsh behrouz yaghoubi saeid shabanlouIn this study, the long-term rainfall in Babolsar city was simulated by means of an optimized AI model. To do this, the extreme learning machine (ELM) and the wavelet transform (WT) were combined. It should be stated that the monthly rainfall values from 1951 to 2019 we MoreIn this study, the long-term rainfall in Babolsar city was simulated by means of an optimized AI model. To do this, the extreme learning machine (ELM) and the wavelet transform (WT) were combined. It should be stated that the monthly rainfall values from 1951 to 2019 were applied, meaning that 70% of the observed values were employed to training the AI models and 30% of rest were utilized to testing these models. Firstly, the activation functions of the ELM models were evaluated; as a result, the sigmoid was chosen as the best activation function. Moreover, the lags of time series were introduced using the autocorrelation function (ACF) that four ELM models were defined through those identified lags. By performing a sensitivity analysis, the superior ELM model was introduced. The values of correlation coefficient (R), variance accounted for (VAF), and scatter index (SI) for the ELM model were respectively computed to be 0.524, 27.064, and 0.819. Furthermore, different mother wavelets were examined and the “dmey” was opted as the best mother wavelet. The wavelet transform enhanced the accuracy of the simulations significantly. For instance, the VAF index for the hybrid WELM model equaled to 86.461. It is noteworthy that the hybrid model was evaluated for different decomposition levels (DL) and then the best one was detected. Also, the (t-1) and (t-12) lags were identified as the most effective input lags. Manuscript profile -
Open Access Article
16 - Investigating Changes in the Intensity of Short-Term Rainfall in the Last Half Century in the Context of Data Scarcity (Case Study: Rasht City)
Mehdi Torabi Alireza ShokoohiBackground and Aim: With the increase in the production of greenhouse gases due to the industrialization of the countries of the world, we are witnessing the occurrence of global warming, which has caused climate changes all over the planet in recent years. One of the e MoreBackground and Aim: With the increase in the production of greenhouse gases due to the industrialization of the countries of the world, we are witnessing the occurrence of global warming, which has caused climate changes all over the planet in recent years. One of the effects of this phenomenon is the change in the behavior of weather parameters such as temperature and precipitation. The effects of climate change phenomenon on precipitation have led to changes in the intensity of precipitation and finally changes in intensity-duration-frequency (IDF) curves of precipitation for different regions of the world and country. Therefore, updating the intensity-duration-frequency (IDF) curves is necessary because of their importance in the design of hydraulic structures used in urban flood management. One of the problems of producing intensity-duration-frequency (IDF) curves is the lack of access to rainfall data with different continuities. The purpose of this research is to use the fractal method to obtain precipitation with different continuities and then evaluate the effect of climate change on the intensity of precipitation in Rasht City. .Method: In this research, the accuracy of the fractal method for generating intensity-duration-frequency curves is first evaluated. Then intensity-duration-abundance curves are produced by using fractal theory and by determining the effect of climate change on rainfall intensity by TREND software, two periods before and after climate change are evaluated and compared.Results: In this research, the validation of the Fractal method shows that the IDF curve production for Rasht city using the Fractal method compared to the IDF curve production using observational data has about a three percent difference. Therefore, this method was used to generate IDF curves for the years when rainfall data with less than three hours of duration was not available. The evaluation of IDF curves with TREND software on the rainfall intensity for different durations demonstrates that the rainfall intensity jump occurred in 2003 towards becoming more intense due to the effect of climate change. For example, for 10 minutes with a return period of 100 years before the effect of climate change, the intensity of rainfall is 158 (mm/h) and after the effect of climate change, the intensity of rainfall is 225 (mm/h). Also, the results showed that the period of short returns has changed more than the period of large returns, that is, the 2-year return period has increased by about 70% and the 100-year return period has increased by about 40%.Conclusion: In this research, by evaluating the fractal method, it was determined that if there is no access to rainfall data with different durations, the fractal method is a suitable method for generating different rainfall durations and generating IDF curves with acceptable accuracy. be Also, the results showed that the jump of intensity-duration-frequency curves occurred under the effect of climate change in 2003, and in the period of climate change, compared to the period before climate change, the intensity of rainfall moved towards more intense rainfall, and this event occurred in the period Short-term returns show a greater increase. Manuscript profile -
Open Access Article
17 - Investigating the Effect of Changes in Frequency and Intensity of Daily Rainfall on its Annual and Seasonal Trends in Kurdistan province
Arash Ranjbar Niazali Ebrahimipak Arash TaftehBackground and purpose: Most of the studies that have been conducted in order to investigate the pattern of temporal and spatial changes of rainfall in rainfed areas have finally resulted in determining the trend of total annual, seasonal, and monthly rainfall in the ta MoreBackground and purpose: Most of the studies that have been conducted in order to investigate the pattern of temporal and spatial changes of rainfall in rainfed areas have finally resulted in determining the trend of total annual, seasonal, and monthly rainfall in the target areas. However, changes in the frequency and intensity of rainfall are among the important parameters that have a great impact on the trend of rainfall and the planning of rainfed areas. The purpose of this study is to investigate the effect of changes in the frequency and intensity of daily rainfall on the trend of annual and seasonal rainfall in Kurdistan province.Research method: For this purpose, the rainfall data of 30 years (1988 to 2017) of four synoptic stations of Sanandaj, Bijar, Qorveh, and Saqez, located in Kurdistan province, were used. After the data homogeneity test, the trend of changes in time series of frequency and amount of rainfall was calculated through the non-parametric Mann-Kendall test and Sen's slope estimator.Findings: The obtained results indicated a decreasing trend between 25 and 31% of total annual rainfall compared to the average of the studied period in four stations and this decrease was related to spring, summer, and winter seasons in most cases. The rainfall trend did not change significantly in the autumn season. Even though the trend of the rainy days in Sanandaj and Qorveh stations had a significant increase of 0.54 and 0.63 days per year, respectively, the results showed that this increase was related to spring rains which have had less intensity than five millimeters per day and cannot be very effective in providing water requirement. The noteworthy point was that the intensity of rainfall has decreased in all stations which is the main reason for the more than 40% decrease in the amount of rainfall during the spring and winter seasons of Sanandaj, Qorveh, and Saqez stations.Results: In general, increasing the frequency of low-intensity rains and decreasing the intensity of rains in rainfed areas can be a serious threat to reducing yield. Therefore, it is necessary to investigate the changes in the frequency and intensity of rainfall, along with its values, in order to determine the distribution pattern of annual and seasonal rainfall in rainfed areas. Manuscript profile -
Open Access Article
18 - The Effect of Climate Change on the Physical and Chemical Properties of Arid and Semi-Arid Soils
Arash Mohammadzadeh Yaser AzimzadehClimate change is one of the most significant global challenges threatening food security now, in the near and far future. This mainly occurs in the form of increasing temperature, change in rainfall pattern, and increase in extreme we MoreClimate change is one of the most significant global challenges threatening food security now, in the near and far future. This mainly occurs in the form of increasing temperature, change in rainfall pattern, and increase in extreme weather events. There are strong evidences demonstrating the vulnerability of agriculture sector in arid and semi-arid regions to climate change. This may directly impact on crops growth and production or indirectly impact on their environments. The ability of soil to produce a crop depends on its physical and chemical properties and these properties are directly and indirectly affected by climatic factors such as temperature and rainfall. Most predictions show that in arid and semi-arid regions, including many regions of Iran, climate change will lead to an increase in temperature and a decrease in rainfall. Therefore, considering the importance and role of temperature and humidity in physical and chemical quality indicators of soil and production stability, it seems that the phenomenon of climate change will have adverse effects on soil and then on crop production. Therefore, it is very important to use the necessary solutions to mitigate these adverse effects and adapt to the upcoming conditions. In this article, by reviewing and summarizing the research on the effects of climate change on the characteristics of arid and semi-arid soils, an attempt has been made to provide some kind of foresight of possible changes in the physical, chemical, and biological properties of soil due to climate change. Manuscript profile -
Open Access Article
19 - Comparison of Data Mining Models Performance in Rainfall Prediction Using Classification Approach (Case Study: Hamedan Airport Synoptic Weather Station)
Morteza Salehi Sarbijan Hamidreza DezfoulianBackground and Aim: Rainfall is one of the complex natural phenomena and one of the most crucial component of the water cycle, playing a significant role in assessing the climatic characteristics of each region. Understanding the amount and trends of rainfall changes is MoreBackground and Aim: Rainfall is one of the complex natural phenomena and one of the most crucial component of the water cycle, playing a significant role in assessing the climatic characteristics of each region. Understanding the amount and trends of rainfall changes is essential for effective management and more precise planning in agricultural, economic, and social sectors, as well as for studies related to runoff, droughts, groundwater status, and floods. Additionally, rainfall prediction in urban areas has a significant impact on traffic control, sewage flow, and construction activities. Method: The objective of this study is to compare the accuracy of classification models, including Chi-squared Automatic Interaction Detector (CHAID), C5 decision tree, Naive Bayes (NB), Quest tree, and Random Forest, k-Nearest Neighbors (KNN), Support Vector Machine (SVM), and Artificial Neural Network (ANN) in predicting rainfall occurrence using 50 years of data from the synoptic station at Hamedan Airport. In this study, 80% of the data is used for training the models, and 20% for model validation and the results obtained from the model executions are compared using metrics such as confusion matrix, Receiver Operating Characteristic (ROC) curve, and the Area Under the Curve (AUC) index. To create the classification variable for rainfall and non-rainfall data, based on rainfall data, the days of the year are categorized into two classes: days with rainfall (y) and days without rainfall (n). Data preprocessing is performed using Automatic Data Preprocessing (ADP). Then, Principal Component Analysis (PCA) is employed to reduce the dimensions of the variables. Results: In this study, the PCA method reduces the dimensions of the variables to 5. Also, approximately 80% of the available data corresponds to rainless days, while 20% corresponds to rainy days. The research results indicated that the KNN model with an accuracy of 91.9% for training data and the SVM model with 89.13% for test data exhibit the best performance among the data mining models. The AUC index for the KNN model is 0.967 for training data and 0.935 for test data, while for the SVM algorithm, it is 0.967 for training data and 0.935 for test data. According to the ROC curve for Hamedan rainfall data, the KNN model outperforms other models. Considering the sensitivity index in the confusion matrix, the KNN and SVM models perform better in predicting non-rainfall occurrence for training data. In terms of the precipitation occurrence prediction, the RT and KNN models show better results according to the specificity index. Conclusion: The results demonstrated that for the RT, C5, ANN, SVM, BN, KNN, CHAID, QUEST, accuracy metrics was obtained 86.82%, 89.78%, 89.55%, 89.96%, 88.06%, 91.9%, 88.29%, 87.46%, 91.9%, respectively for training data. Moreover, for test data, the accuracy metrics for this model was obtained 83.82%, 87.9%, 88.12%, 89.13%, 87.12%, 89.13%, 87.12%, 88.19%, 86.93%, 86.76%, respectively. The AUC index in the training data for RT, C5, ANN, SVM, BN, KNN, CHAID QUEST models was 0.94%, 0.99%, 0.94%, 0.94%, 0.93%, 0.97%, 0.93%, 0.89%, respectively. In addition, for the test data, this metric was evaluated 0.89%, 0.89%, 0.93%, 0.94%, 0.92%, 0.90%, 0.92%, 0.88% respectively. As observed, considering accuracy metric and AUC index for training data KNN model and for test data SVM model were more sufficient in rainfall prediction. Manuscript profile -
Open Access Article
20 - Evaluation of temporal variation of splash erosion in different slopes and agricultural and forest land uses
Ashkan Yusefi Ahmad Farrokhian Firouzi Bijan Khalili MoghaddamSoil erosion is one of the major worldwide environmental challenges and its related destructive effects cannot be ignored at both inside and outside of a region. Splash and transport of soil particles by raindrops are the initiating mechanisms of water erosion. The obje MoreSoil erosion is one of the major worldwide environmental challenges and its related destructive effects cannot be ignored at both inside and outside of a region. Splash and transport of soil particles by raindrops are the initiating mechanisms of water erosion. The objective of this research was to investigate temporal variations of splash erosion in different slopes and land uses using a rainfall simulator. The experiment was conducted as factorial based on completely randomized design with three replicates. The experimental treatments were consist of slope at two levels (5 and 15%), duration of rainfall at four levels (5, 10, 15 and 20 minute) and different land uses (forest and agriculture).The results indicated that amount of splash increased with increasing rainfall duration. The amount of splash erosion of the 20-min rainfall duration was 2.08, 1.76 and 1.08 times more than of 5, 10 and 15-min, respectively. The average soil loss by splash erosion in agricultual and forest land uses was 29.37 and 25.56g.m-2, respectively. Furthermore, the results showed that as slope increased from 5 to 15% the amount of splash erosion increased 11%. In general, at all rainfall durations, splash erosion increased significantly with changes in slope steepness (from 5 to 15%) and land use from forest to agriculture, but there was no significant difference between the15 and 20-min rainfall durations. Manuscript profile -
Open Access Article
21 - Effect of type and application level of polyacrylamide on soil loss
Seyed Hamidreza Sadeghi Zeinab Karimi Hossein Ali BahramiSoil erosion is one of the basic issues at global, regional and local scales. Considering management plans in hindering its effects has therefore significant importance. Additionally, application of additive materials including polyacrylamide is one of new techniques in MoreSoil erosion is one of the basic issues at global, regional and local scales. Considering management plans in hindering its effects has therefore significant importance. Additionally, application of additive materials including polyacrylamide is one of new techniques in the field of soil erosion control. Despite of application of Polyacrylamide in runoff and soil erosion management, its contemporary effect in type and the amount of usage has been less considered. The present study was therefore carried out in order to determine the impressibility of soil loss in small plots from application of flour and soluble polyacrylamide in different levels of 0.4, 2, and 6 g m-2 under the laboratory conditions. To this end, three plots with dimensions of 0.5*0.5m and 30% slope were used. In order to apply the current study, rainfall was simulated on study plots with intensity of 50 and 80 mm h-1 and respective duration of 17 and 8 min after 48 h from using polyacrylamide in flour and soluble types. The results obtained from statistical tests verified significant (P=0.00) effect of polyacrylamide type and different rainfall intensities on the amount of soil loss in different levels of the polyacrylamide usage. In addition, the performance of powder application of polyacrylamide under study conditions was found better than that recorded for the solute application and therefore is recommended for the purpose of soil loss control. Manuscript profile -
Open Access Article
22 - Trend of soil loss and sediment concentration changeability due to application of polyacrylamide
Seyed Hamid Reza Sadeghi Zeinab Hazbavi Habibollah Younesi Morteza BehzadfarSoil erosion control is very important to natural resources conservationists and managers. For this reason, different methods and practices have been developed and used to control soil erosion. Application of soil amendments is one of the most recent technologies in soi MoreSoil erosion control is very important to natural resources conservationists and managers. For this reason, different methods and practices have been developed and used to control soil erosion. Application of soil amendments is one of the most recent technologies in soil and water conservation. However, different aspects of its application have not comprehensively been considered. Hence, the present research intended to assess the application of polyacrylamide (PAM) as an important soil amendment on soil loss and sediment concentration. The research was conducted under simulated rainfall condition in small plots on the loess soils of Bojnourd City located in Northern Khorasan Province, Iran. Accordingly, the laboratory experiments were conducted in treatments of 0 (control), 0.4, 0.6, 1, 2, 3, 4 and 6 g m-2 of polyacrylamide with simulated rainfall intensity of 72 mm h−1 with 30 minutes duration in three replicates. The collected data on soil loss and sediment concentrations showed that polyacrylamide significantly reduced both soil loss (P=0.04) and sediment concentration (P= 0.004). The maximum sum amount of soil loss and sediment concentration were 49.32 g and 10.79 g/l, respectively, at control treatment and their minimum were 18.03 g and 6.93 g/l respectively, at 6 g/m2 level of PAM application.Also, the results showed that the polyacrylamide had no significant effect on temporal changes of soil loss and sediment concentration during event duration (P>0.3). The results suggest that PAM, as an available amendment, can be recommended for water and soil conservation purposes. Manuscript profile -
Open Access Article
23 - Enhancement of flood warning system performance using stochastic rainfall threshold curve
Ahmad SharafatiFlood warning systems are the important and effective approaches to prevention or mitigation life and property loss in any flood event. All flood warning systems use one or more flood event indicator such as climatological signals. Rainfall threshold curve is one the co MoreFlood warning systems are the important and effective approaches to prevention or mitigation life and property loss in any flood event. All flood warning systems use one or more flood event indicator such as climatological signals. Rainfall threshold curve is one the conventional flood events indicator in many flood warning systems. In this respect, observed or forecasted rainfall was compared with rainfall threshold to notify flood event. Application of some assumptions like constant rainfall patterns and rainfall-runoff model parameters such as loss and base flow is known as the main drawback of using conventional rainfall threshold curves. This study has considered uncertainties of rainfall-runoff model parameters and variables for extracting rainfall threshold curve, while solving shortcomings of the previous works. Results of this study demonstrated that extraction of the rainfall threshold curves by considering uncertainties of the mentioned variables and parameters represents a very higher accuracy respect to conventional rainfall threshold curves. Manuscript profile -
Open Access Article
24 - Effect of plot size on measured runoff and sediment yield from natural rain-storms
Farrokh Asadzadeh Manoochehr Gorji Alireza Vaezi Reza Sokouti Salman MirzaeeErosion Plots are widely used to evaluate the main factors affecting soil erosion. Therefore, understanding the effects of different variables such as spatial scale on their performance is needed. This study was carried out to assess the effect of plot scale on measured MoreErosion Plots are widely used to evaluate the main factors affecting soil erosion. Therefore, understanding the effects of different variables such as spatial scale on their performance is needed. This study was carried out to assess the effect of plot scale on measured runoff and sediment yield at event scale. To represent different spatial scales, plots with seven sizes differing in length (2, 5, 10, 15, 22.1, 25, and 30 m) and width (1, 1, 1.2, 1.6, 1.8, 2, and 2.4 m, respectively) were constructed in Poldasht region, west Azarbayjan province, northwest Iran. For each size of plots, specific runoff and sediment yield were separately measured for 11 runoff producing natural storms during the study period from September, 2010 to September, 2011. The results indicated that the unit area runoff and sediment yield decreases with power form relation as plot area or length increases. Statistical analysis of runoff and sediment yield data showed that, in most cases, there is a significant difference between the results of 10 m or shorter in length, plots and longer plots (p<0.05). However, there was no significant difference between the results of 15 m and longer plots. Based on these results, plots with 10 to 15 m in length were able to produce comparable results with large plots. Manuscript profile -
Open Access Article
25 - Effect of rice straw on surface runoff and soil loss in small plots
Seyed Hamid reza Sadeghi Ehsan Sharifi Moghadam Leila GholamiSoil erosion is one of the most challenging issues in optimal conservation of soil and water resources. Land surface cover affects runoff production and soil loss processes. Nowadays, miscellaneous amendments and conditioners are being applied to conserve water and soil MoreSoil erosion is one of the most challenging issues in optimal conservation of soil and water resources. Land surface cover affects runoff production and soil loss processes. Nowadays, miscellaneous amendments and conditioners are being applied to conserve water and soil worldwide. However, the role of environmentally friend and available organic amendments have been rarely considered. This study was therefore taken place in order to assess the effect of rice straw (0.5 kg m-2) on runoff volume and soil loss on a sandy clay loam placed in three small plots (0.5×0.5×0.3m) with 20% slope steepness using rainfall simulator. The study plots were then subjected to 50 and 90 mm h-1 rainfall intensities for 15 minutes after spreading rice straw on the soil surface. The results showed that the rice straw treatment under 50 and 90 mm h-1 rainfall intensities and in comparison with control plot reducing the runoff about 90% and 96%, respectively. In addition, soil loss was completely controlled in treated plots and under both studied rainfall intensities. All differences were found statistically significant at 1% significancy level. Manuscript profile -
Open Access Article
26 - Effect of wheat straw on changing time to runoff and runoff coefficient in laboratory plots under rainfall simulation
Ataollah Kavian Maziar Mohammadi Moghadaseh Fallah Leila GholamiThe runoff and soil erosion is most basic of environmental, agricultural and food production problems in the world, that these had adverse effects on the natural ecosystems and man-managed. One of the most important factors of runoff and soil erosion control is using or MoreThe runoff and soil erosion is most basic of environmental, agricultural and food production problems in the world, that these had adverse effects on the natural ecosystems and man-managed. One of the most important factors of runoff and soil erosion control is using organic and inorganic mulches, that they have most role in runoff and soil erosion control. Therefore in this study, for studying time to runoff and runoff coefficient changes used from an organic mulch (wheat straw mulch) in laboratory conditions. The experiments was done using rainfall simulation, in slope of 30% and plot scale of 0.5 m2 with 3 replications, with two cover percent of 50 and 90% and rainfall intensities of 50 and 100 mm h-1 for 10 min and then the time to runoff and runoff coefficient rates measured. The results showed that in rainfall intensities of 50 and 90 mm h-1, the conservation treatment could increase and decrease time to runoff and runoff coefficient, respectively and the cover of 90% had more effect in increasing time to runoff and decreasing runoff coefficient. The enhancement percent of time to runoff in rainfall intensities of 50 and 100 mm h-1 (cover of 90%) was 102.37 and 70.80%, respectively. The reduction percent of runoff coefficient in rainfall intensities of 50 and 100 mm h-1 (cover of 90%) also was 36.58 and 27.31%, respectively. The effect of conservation treatment and rainfall intensity variables evaluated significant expect in the effect of rainfall intensity × conservation treatment. Manuscript profile -
Open Access Article
27 - Verifying precipitation data of TAMAB and meteorology institute in Urmia basin
Navid Ghajarnia Abdolmajid Liaghat Peyman Daneshkar ArastehWater resources management, forecasting, and decision making require reliable estimates of precipitation. Therefore, a normal and an inevitable part of any hydrological or water management project before starting the research is analyzing the accuracy of time series. Fo MoreWater resources management, forecasting, and decision making require reliable estimates of precipitation. Therefore, a normal and an inevitable part of any hydrological or water management project before starting the research is analyzing the accuracy of time series. For this purpose by using statistical tests, the time series are analyzed heterogeneous and improbable fluctuations of data and if needed are corrected or omitted. Although usually passing the statistical tests, scientifically verifies the efficiency of the data, more precise verifications on the data may lead to different results. Therefore, in this study by choosing precipitation data of Urmia basin as a case study, final results of some statistical tests on the efficiency of the data are analyzed. Careful and precise analysis of the time series especially in comparison with neighboring stations shows that full reliance on the statistical tests alone is not enough for analyzing the efficiency of the time series and the results of these tests may mislead users on the true condition and efficiency of the data. Based on the results of this study, only 2.4 percent of the data need correction or must be omitted; nevertheless, more precise analysis through data shows that about 12.6 percent of the data are completely unsuitable and must be omitted. Manuscript profile -
Open Access Article
28 - Assessing Spatial-Temporal Changes of Rainfall Variability Indices in Ardabil Province Rain gauge stations
hamed amini Raoof Mostafazadeh Mohammad AhmadiBackground and Objective: The rainfall is one of the main elements of the climate in each region. One of the characteristics of arid and semi-arid regions is a low rainfall with high fluctuations. Hence, changes in rainfall patterns, including spatial and temporal chang MoreBackground and Objective: The rainfall is one of the main elements of the climate in each region. One of the characteristics of arid and semi-arid regions is a low rainfall with high fluctuations. Hence, changes in rainfall patterns, including spatial and temporal changes in rainfall, are of particular importance. The patterns of rainfall distribution, determine the rainfall during the time. The purpose of the present study was to investigate spatial and temporal changes of rainfall variability indices in the gauge stations of Ardabil province.Material and Methods: In this study to determine the rainfall variability from the monthly rainfall with a 24-year period from the year of 1989 to 2013 (based on current statistics) in the watersheds of Ardabil province has been used. In order to calculate the quantitative variability of rainfall in the studied stations, Shannon, Simpson, Index of variability, rainfall variability index (RVI), MCIntosh, Berger-Parker, Rainfall anomaly Index (RAI) were used. After calculating these indices, the spatial variations of the indices at the studied stations were performed using the interpolation methods and the Inverse Distance Weighting method in the Arc Map software, and also the non-parametric Mann-Kendall method was used to determine the temporal variation of the values of rainfall variability indices.Findings: According to the results of the interpolation of these indices, the spatial variations of the Simpson, Index of Variability, McIntosh and the Berger-Parker indices are similar to the one in which the high variation values in the eastern regions include stations of Aladizgeh, Namin, Niaraq, Abi Beiglu and Khosh Abad and the northern part of the province are observed.Discussion and Conclusion: In general, it can be said that regions of the province, in the proximity of the provinces of Gilan and East Azerbaijan, have more variability in rainfall values due to the impact of the air masses and rainfall of the Caspian and Mediterranean fronts. Also, the results of the trend test indicated a significant increase in rainfall variability indices that could lead to a change in the seasonal distribution pattern of rainfall values in different months and the results show similar behavior in most of the indices. Manuscript profile -
Open Access Article
29 - Climate Change Impact on Extreme Rainfalls in Arid Region of Iran
Mohammad Reza Khazaei hadis khazaee bahram saghafianBackground and Objective: One of the major impacts on climate changes is change in extreme precipitation regime in the future, which have to be predicted to counteract the harmful effects of climate change. In this paper, climate change impact is assessed on extreme rai MoreBackground and Objective: One of the major impacts on climate changes is change in extreme precipitation regime in the future, which have to be predicted to counteract the harmful effects of climate change. In this paper, climate change impact is assessed on extreme rainfalls in arid regions of Iran. Method: Future scenarios are downscaled using the NSRP model. Long-term daily rainfall series are generated for current climate and future scenarios. By comparing the distribution of extreme daily rainfalls for current and future conditions, the impacts of climate change on extreme rainfalls are assessed. In downscaling method, a wide range of statistics of large-scale scenarios has been transferred to downscaled scenarios. The understudying stations are in Bam, Zahedan, Tehran and Yazd synoptic stations as representatives of the arid regions of Iran. Findings: Validation results indicate that the performance of this method in simulating daily rainfall series and distribution of extreme rainfall is acceptable. Results for most of stations and scenarios show that intensity of extreme daily rainfalls will increase in the future while average rainfall will decrease. As instance, in Yazd, extreme rainfall of 50 years return period would increase between 14 to 58 percent, while the average precipitation will change between +3 to -20 percent. Discussion and Conclusion: These results indicate that the precipitation situation in arid areas of Iran will worsen in the future. Therefore, more extensive investments and taking preventive activities to adapt to climate change is essential. Manuscript profile -
Open Access Article
30 - Investigation of Synoptic Conditions coincided with the Occurrence of West and Southwest Floods on March 31 and April 1, 2019
mahdi khazaei Amir Hossain nikfalBackground and Objective: The purpose of this study is to identify and investigate the synoptic systems that led to the extensive and destructive flood events in the west and southwest of the country on March 31 and April 1, 2019. Method: In order to study the synoptic MoreBackground and Objective: The purpose of this study is to identify and investigate the synoptic systems that led to the extensive and destructive flood events in the west and southwest of the country on March 31 and April 1, 2019. Method: In order to study the synoptic conditions in coincided with the event of heavy rainfall leading to the floods, in addition to using NOAA18 satellite images, sea level pressure data, sea level specific humidity, geopotential height and omega at pressure level 850, 700 and 500 hPa, Relative humidity pressure at 700 hPa, U and V component from pressure 1000 to 200 hPa with a resolution of 2.5 ° to 2.5° latitude from the National Center for Environmental Prediction and the National Center for Atmospheric Research (NCEP / NCAR) Received and the maps were plotted. Findings: Existence of a deep cyclone at sea level pressure to 500 hPa pressure from eastern Mediterranean to western of Iran and also the establishment of a subtropical jet stream with meridian direction (southwest - northeast) in the southwest and west of the country and finally the intense vertical shear of horizontal wind from sea level pressure to 200 hPa in the study area, It is known as the main factors of cause of instability in the west and southwest of the country. existence Specific humidity of 14 to 18 g / kg at sea level pressure and relative humidity of 95 to 100% at a pressure of 700 hPa have also been identified as suitable moisture conditions in the study area. Discussion and Conclusion: The results of this study show that on March 31 and April 1, 2019, the atmosphere of the western and southwestern regions of the country in all depths of the troposphere layer experienced severe instability due to the establishment eastern part of a deep cyclone. Above the cyclone mentioned above, located meridional flows of subtropical jet stream which has intensificated the instability to the depth of the tropospheric layer. Also moisture advection from the western Arabian Sea, the Red Sea and the Persian Gulf has caused form cells from thick convective clouds throughout the west and southwest of the country. The heavy rains resulting from these convective clouds have caused severe and extensive floods in this area of the country. Manuscript profile -
Open Access Article
31 - Exploration of Randomness Characteristic of Rainfall Pattern Using RDP Model in Symareh Catchment.
Ahmad Sharafti Mohammad Reza KhazaeiBackground and Objective: Rainfall pattern is one of the most important and effective variable in flood simulation. Variation of rainfall intensity in each event is illustrated by rainfall pattern. Many random variable cause the stochastic property of rainfall pattern. MoreBackground and Objective: Rainfall pattern is one of the most important and effective variable in flood simulation. Variation of rainfall intensity in each event is illustrated by rainfall pattern. Many random variable cause the stochastic property of rainfall pattern. According to the relation between rainfall pattern and flood, uncertainty of flood is related to the variability of rainfall pattern. Method: In this study, the RDP (Rainfall Data Processor), is used to quantify randomness characteristic of rainfall pattern in Symareh catchment. Findings: The obtain result shown, the Brust factor in rainfall events with long time duration and more depth is less than others. Also, more than 60 percent of observed events in Symareh catchment are belong to type 1 and 2 categories. Discussionand Conclusion the obtained result shown, the fraction of cumulative rainfall depth has not the same pattern. Also, the minimum uncertainty are related to the rainfall patterns that belong to the type 2 and has less depth and also more duration. Manuscript profile -
Open Access Article
32 - Stochastic Generation of Rainfall Pattern with RPG Model
Ahmad Sharafti Bagher ZahabiyounIntroduction: The existence of random variables is the major reason for uncertainty in floodmodeling. One of the major random variables that can affect the shape of flood hydrographs is stormpattern among others. Storm pattern include duration, depth and time distributi MoreIntroduction: The existence of random variables is the major reason for uncertainty in floodmodeling. One of the major random variables that can affect the shape of flood hydrographs is stormpattern among others. Storm pattern include duration, depth and time distribution for any eventproducing its corresponding flood event. Therefore, uncertainty analysis of flood modelingdepends on uncertainty analyses of those effective variables of storm pattern.Material and method: RPG model is introduced and it used of Monte Carlo simulation andBootstrap Resampling to generate rainfall pattern on Seymareh catchment.Result and discussion: Result of this paper show that 90 percent of observed rainfall duration and 98percent of observed rainfall pattern exit in generated RPG band. Manuscript profile -
Open Access Article
33 - Simulation of Rainfall-Runoff for Gharesou Watershed Using SWAT Model
Mohammadreza Goodarzi Bagher Zahabiyoun Alireza Massah BavaniBackground and Objective: Rainfall-runoff Simulation is very important in many hydrological studies, such as investigating the effects of climate change on river flow, flood prediction and planning of water resources. SWAT model was used to simulate stream flow transpor MoreBackground and Objective: Rainfall-runoff Simulation is very important in many hydrological studies, such as investigating the effects of climate change on river flow, flood prediction and planning of water resources. SWAT model was used to simulate stream flow transport, sediment and quality variables (nitrogen and phosphorus...) in the watershed areas. SWAT model is a distributed time series model with physical basis. This model has an ability to connect to GIS, in a way that vast volumes of data as information layers such as land use, soil map and the DEM using GIS capabilities are used by the model. The main purpose of this study is testing SWAT model performance as a simulator of flow at the catchment scale. Method: This study attempts to prepare a model for Gharesou catchment. Moreover, the parameters were optimized using SWAT-CUP optimizer. Findings: The model was calibrated for the years 1992-1996 and validated for the years 1998-2000. The coefficient of determination (R2) for monthly flow was equal to 0.82 and Nash-Sutcliffe coefficient (Ens) was equal to 0.8 in the calibration period while in the validation period these coefficients were 0.77 and 0.73, respectively. Conclusion: These results indicate the success of the SWAT model, using optimized parameters, for the stream flow simulation in Gharesou catchment. Manuscript profile -
Open Access Article
34 - Daily Stream Flow Simulation in a Data-Poor Basin
Mohammad Reza Khazaei Bagher Zahabiyoun Bahram SaghafianIntroduction: Rainfall-runoff modeling is one of the keystones of scientific hydrology andenvironmental management. Therefore the researchers continuously try to find new approaches forimprovement of existing models or modeling methodologies.Material and Methods: In thi MoreIntroduction: Rainfall-runoff modeling is one of the keystones of scientific hydrology andenvironmental management. Therefore the researchers continuously try to find new approaches forimprovement of existing models or modeling methodologies.Material and Methods: In this paper, daily stream flow at the outlet of a watershed in southwesternIran was simulated using a conceptual continuous rainfall-runoff model. In encountering with theproblem of poor quality data, required data such as runoff, rainfall and PET were prepared using aspecific approach.Results and Discussion: The results showed that the Nash-Sutcliffe efficiency was 0.80 and thecoefficient of determination was 0.82 during calibration and the Nash-Sutcliffe efficiency was 0.83and the coefficient of determination was 0.83 during validation. Furthermore statistics of observedstream flow were preserved in simulated stream flow. The results showed that this approach issuccessfully applicable for daily rainfall-runoff modeling when the quality of the input data is notadequate Manuscript profile -
Open Access Article
35 - Evaluation of people’s attitude towards noise pollution in the crowded streets of Rasht city in 2000
Marzieh Sadat Ayatollah Shirazi Noushin Birjandi Karim Keshavarz ShokriBackground and Objective: Rainfall-runoff simulation is very important in many hydrological studies, such as investigating the effects of climate change on river flow, flood prediction and planning of water resources. SWAT model was used to simulate stream flow transpor MoreBackground and Objective: Rainfall-runoff simulation is very important in many hydrological studies, such as investigating the effects of climate change on river flow, flood prediction and planning of water resources. SWAT model was used to simulate stream flow transport, sediment and quality variables (nitrogen and phosphorus) in the watershed areas. SWAT model is a distributed time series model with physical basis. This model has an ability to connect to GIS, in a way to cover a vast volume of data as information layers such as land use, soil map and DEM while GIS capabilities are used by the model. The main purpose of this study is testing SWAT model performance as a simulator of flow at the catchment scale. Method: This study attempts to prepare a model for Gharesou catchment. Moreover, the parameters were optimized using SWAT-CUP optimizer. Findings: The model was calibrated for the years 1992-1996 and validated for the years 1998-2000. The coefficient of determination (R2) for monthly flow was equal to 0.82 and Nash-Sutcliffe coefficient (Ens) was equal to 0.8 in the calibration period while in the validation period these coefficients were 0.77 and 0.73, respectively. Conclusion: These results indicate the success of the SWAT model, using optimized parameters, for the stream flow simulation in Gharesou catchment. Manuscript profile -
Open Access Article
36 - Study the effect of some different Environmental factors on dispersal of dominant broadleaf weeds in irrigated wheat fields.
Omid Lotfifar سمانه متقی hamid Mostafavi Seyed Mehdi MirtaheriThis research was conducted to study the 7 common broadleaves dispersal of irrigated wheat fields in response to some environmental factors. Research data were obtained from sampling of weed communities and using weed dispersal maps (produced by GIS). The effects of env MoreThis research was conducted to study the 7 common broadleaves dispersal of irrigated wheat fields in response to some environmental factors. Research data were obtained from sampling of weed communities and using weed dispersal maps (produced by GIS). The effects of environmental factors (climates, soil order and annual mean of soil temperature, rainfall and evaporation) on dispersal of dominant weed were studied. Result showed the effect of studied factors on each weed dispersal was different. The highest dispersal of Descurainia sophia was observed in semiarid climate, 250-500mm rainfall, 0-6°C soil temperature, 3500-4000 mm evaporation, eridisols soil and 1600-1800 m elevation. The highest Galium tricornatum dispersal was observed in wet climate, 1000-1250 mm rainfall, 6-12°C soil temperature, 1500-2000 mm evaporation, inceptisol soil and 1800-2000 m elevation. Cardaria draba in wet climate, 50-250 mm rainfall, 0-6°C soil temperature, 1500-2000 mm evaporation, aridisol soil and 2600-2800 m elevation had highest dispersal. The highest dispersal of Polygonum aviculare was observed in sever-arid soil, 50-250 rainfall, 12-18°C soil temperature, 2000-2500mm evaporation, aridisol soil and 2400-2600m elevation. Alhagi psudalhagi in arid soil, 50-250mm rainfall, 18-24°C soil temperature, 2000-2500mm evaporation, aridisol soil and 1000-1200m elevation had the highest dispersal. The highest dispersal of Carthamus oxycantha was observed in 50-250mm rainfall, 6-30°C soil temperature, 2500-3000mm rainfall, entisol soil and 200-400m elevation. Also the highest Convovulus arvensis dispersal was observed in moderate semiarid climate, 250-500mm rainfall, 6-12°C soil temperature, 1000-4000mm evaporation, inseptisol soil and 2600-2800m elevation. Manuscript profile -
Open Access Article
37 - Investigation of flood risk zoning in Mazandaran province in GIS environment (Case study: Babolrood watershed)
Karim Solaimani Behrooz MohseniThe purpose of this study is to create up-to-date and accurate flood risk maps in the Babolrood watershed using synoptic station data and physiographic information. The flood potential was then modeled using GIS, satellite imagery, and layer integration. The final flood MoreThe purpose of this study is to create up-to-date and accurate flood risk maps in the Babolrood watershed using synoptic station data and physiographic information. The flood potential was then modeled using GIS, satellite imagery, and layer integration. The final flood risk map was prepared based on a combination of factors, climatic and physical elements coefficient, and rainfall intensity. The results of flood risk zoning showed that sub-basin B2 has a higher score than other basins and has a higher flood potential with the scoring method under the same conditions. Sub-basins B11121, B211INT, B11121INT, and B211 were then identified in the next priorities in terms of flooding, respectively. Finally, based on the flood intensity index method, sub-basins B11121, B211INT, and B1INT with the highest flood coefficient were identified as the most flood sub-basins. By increasing the percentage of vegetation canopy in the tributaries of the basin and based on the flood potential zoning map, a significant part of rainwater runoff can be controlled and absorbed in the same place. The results show that part of the basin is affected by the risk of floods with very high potential, which is mainly located downstream and leading to the sea at the outlet of the basin. Networks ranked 3 and 4 are known as flood zones and flood control areas to the downstream areas. River networks with a rank of 5 and above are located in the area of floodplains or rivers downstream and usually have surface and extensive floods. Also, in some areas, which have a relatively high altitude, due to the snowfall of the basin, the number of runoff increases and causes flooding in the area. Therefore, monitoring the withdrawal of river loan resources and constructions (change of use) are among the priority proposals in this basin. Manuscript profile -
Open Access Article
38 - Evaluation of rainfall on a daily, monthly and annual basis using satellite imagery (Case study: west boundary basin of Iran)
Ghazaleh Madadi Saeid Hamzeh Ali Akbar NorooziPrecipitation variable is the key parameter of agricultural and hydrometeorology studies. Therefore, measurement and estimation of rainfall at the regional level help to understand the manner of water and energy cycles. In spite of the high variability of te MorePrecipitation variable is the key parameter of agricultural and hydrometeorology studies. Therefore, measurement and estimation of rainfall at the regional level help to understand the manner of water and energy cycles. In spite of the high variability of temporal and spatial precipitation quantity, precipitation monitoring using ground stations at regional scales is considerably difficult. The use of satellite images with high spatial resolution is therefore recommended. However, it is first necessary to evaluate temporal and spatial accuracy of data. The aim of this study was to evaluate the accuracy of Tropical Rainfall Measuring Mission (TRMM) satellite data for estimating daily, monthly, and annual rainfall on a regular spatial scale (0.25° ×0.25°) during 2000-2012, and to compare these estimated data with precipitation data at 30 stations (synoptic and climatological) in the west boundary basin of Iran. The Pearson correlation coefficient was calculated daily, monthly, and annually for the mentioned rainfall period changes. The results indicated a significant correlation (p<0.05) among the monthly and annual collected data of terrestrial and satellite precipitation. The relationship between monthly precipitation data from satellite images and observed data from stations were also determined using a linear and nonlinear regression for each year. The model reliability was also subsequently determined using statistical validation. Manuscript profile -
Open Access Article
39 - Potential impact of drought on Mikkes River flow (Morocco)
Kaltoum Belhassan Ashok Vaseashta Mohammed Abdelbaset Hessane Hafizullah Rasouli Mohammed KA Kaabar Emad Kamil Hussein Muhammad Adnan -
Open Access Article
40 - Relationship between River Flow, Rainfall and Groundwater pumpage in Mikkes Basin (Morocco)
K. BelhassanThis paper investigates the relationship between river flow, rainfall and groundwater pumpage in the Mikkes stream during the period 1968-2009. The Mikkes basin is located in the north center of Morocco and consists of three different zones that represent diversified ge MoreThis paper investigates the relationship between river flow, rainfall and groundwater pumpage in the Mikkes stream during the period 1968-2009. The Mikkes basin is located in the north center of Morocco and consists of three different zones that represent diversified geologies. This basin includes a phreatic and confined aquifer in Saïs basin and a shallow aquifer in the Tabular Middle Atlas. Analysis of monthly medium flows between 1968 and 2009 shows an approximate oceanic system which is characterized by two hydrological seasons. First a period of high waters in winters which is conditioned by the pluviometric contributions and the second is a low water period in summer which is conditioned by evapotranspiration. The mode of this River can be called a pluvio- evaporal type. The high deficit of the Mikkes stream (between 1968-1979 and 1980-2009) is about 76% and could be the combined effect of drought and groundwater pumpage. Water table variations could be conditioned by climatic changes and regional geology. Actually, the annual water table variations show a drop in ground water levels, which is due to the combined effect of reduction in precipitation that has reduced the natural recharge of groundwater, and the increase in pumping which is increasing year by year for more than 80 years in this region. In addition, free-water tables are much more susceptible to pumpage when compared to the confined aquifer. Thus, the water table and piezometric heads of the Mikkes basin do not demonstrate a uniform sensitivity to the drought. High rainfall between 1995 and 1997 had affected the groundwater levels of Mikkes with an increase in piezometric level. The monthly piezometric variations of free-water table are characterized by a seasonal operation: groundwater recharge and discharge. Manuscript profile -
Open Access Article
41 - The Effect of Conventional and Conservation Tillage Methods on the Improvement of Wheat Yield in Different Planting Dates and Seeding Rates
Nosratolla Haidarpour Raham Mohtashami Amin NamdariProduction in areas under rainfed cultivation is always associated with different constraints that among them, changes in precipitation and air temperature from year to year are widespread and uncontrollable. In this regard, the current study was conducted in order to c MoreProduction in areas under rainfed cultivation is always associated with different constraints that among them, changes in precipitation and air temperature from year to year are widespread and uncontrollable. In this regard, the current study was conducted in order to compare conservation and conventional tillage methods on wheat yield in sowing dates before and after effective autumn rainfall. The experiment was carried out as split-split plots based on a randomized complete block design with 3 repetitions in two years 2018 to 2020. Experimental treatments included planting time as main plots with two levels D1= before rainfall and D2= after rainfall tillage method as sub-plots including T1= conservative and T2= conventional and seeding rate as sub-sub-plots including S1= 200, S2=300 and S3= 400 seeds. The results demonstrated that although the planting date and seeding rate had no significant effect on the studied traits, the values obtained from the cultivation before rainfall and under 300 and 400 seeding rates were remarkably better. Tillage method caused a significant difference in grain yield and biomass of treatments 3634 and 8394 kg. ha-1, respectively, whereas conventional tillage the values were 2819 and 6114 kg. ha-1. Conservation tillage and cultivation before rainfall associated by using 300 seeds/m2 led to the highest values in number of plants, spikes, and 1000-grain weight compared to conventional method and cultivation before rainfall. Consequently, considering the cost of production, pre-autumn rainfall sowing under conservation tillage and with a 300 seeds/m2 is recommended for Gachsaran region. Manuscript profile -
Open Access Article
42 - ارزیابی روشهای تحلیل بارشهای کوتاهمدت (مطالعه موردی: ایستگاه سینوپتیک شهرکرد)
حسین صمدی بروجنی کیومرث عماد روح الله فتاحی برآورد حداکثر دبی جریانهای سطحی ناشی از رواناب برای حوزههای آبریز فاقد دادههای طولانی مدت هیدرومتری، مبتنی بر مدلهای بارش- رواناب است. دادههای بارشهای کوتاه مدت از مهمترین اطلاعات مورد نیاز در استفاده از این قبیل مدلهاست. در بسیاری از نقاط دنیا More برآورد حداکثر دبی جریانهای سطحی ناشی از رواناب برای حوزههای آبریز فاقد دادههای طولانی مدت هیدرومتری، مبتنی بر مدلهای بارش- رواناب است. دادههای بارشهای کوتاه مدت از مهمترین اطلاعات مورد نیاز در استفاده از این قبیل مدلهاست. در بسیاری از نقاط دنیا و از جمله ایران دادههای کیفی و کمی ثبت شده مناسبی از بارشهای کوتاه مدت در اختیار نیست. روشهای متعددی جهت برآورد بارشهای کوتاه مدت بر اساس سایر دادههای باران سنجی از قبیل بارشهای روزانه و ماهیانه پیشنهاد شده است. در این تحقیق با استفاده از رگبارهای ثبت شده در ایستگاه سینوپتیک شهرکرد، واقع در استان چهارمحال و بختیاری، روابط منطقه ای برآورد بارشهای کوتاه مدت و روش نسبت بارشهای کوتاه مدت به حداکثر بارش 24 ساعته مورد مقایسه قرار گرفته است. نتایج نشان داد نسبتهای استخراج شده از منحنی­هایSCS و روابط منطقه­ای موجب برآورد دست بالا می­گردند. با توجه به سادگی استفاده از روش نسبتها، می­توان پس از استخراج نسبتهای پیشنهادی SCS برای منطقه مورد نظر، از این روش به عنوان روشی قابل قبول استفاده نمود. همچنین نتایج نشان داد با اعمال ضریب اصلاحی 7136/0 در روابط قهرمان آبخضر، مقادیر "شدت- مدت- فراوانی" رگبارها را برای منطقه شهرکرد با خطای مطلق 4 درصد بدست آورد. در نهایت یک رابطه لگاریتمی با ضریب تعیین 98/0 برای تهیه منحنی­های "شدت-مدت- فراوانی" ایستگاه شهرکرد ارائه شد. Manuscript profile -
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43 - ارزیابی مدلهای CMIP5 جهت شبیه سازی بارش با استفاده از ترکیب دادههای بارش شبکهای APHRODIT و بارش ماهواره ای PERSIANN-CDR در سراسر استان خوزستان
کاظم رنگزن علی شهبازی زهرا جریده مصطفی کابلی زادهیکی از مهم ترین محدودیت های مدل های گردش عمومی جو، بزرگ مقیاس بودن متغیرهای اقلیمی شبیه سازی شده می باشد. بنابراین می بایست به روش های مختلف ریزمقیاس شوند تا توانایی لازم جهت برازش به منطقه مورد مطالعه را داشته باشند. انتخاب مدل GCM مناسب ب Moreیکی از مهم ترین محدودیت های مدل های گردش عمومی جو، بزرگ مقیاس بودن متغیرهای اقلیمی شبیه سازی شده می باشد. بنابراین می بایست به روش های مختلف ریزمقیاس شوند تا توانایی لازم جهت برازش به منطقه مورد مطالعه را داشته باشند. انتخاب مدل GCM مناسب برای محدوده مورد مطالعه نقش بسیار مهمی در شبیه سازی پارامتر موردنظر (بارش) برای آینده دارد. در این تحقیق از مدل های CMIP5 شامل BCC-CSM1.1.M، MPI-ESM-MR و MPI-ESM-LR به منظورارزیابی مدل ها در دوره پایه و مشخص کردن بهترین مدل جهت برازش به منطقه مورد مطالعه استفاده شد. بدین ترتیب که ابتدا هیستوریکال مدل و دیتای شاهد (ترکیب بارش ماهواره ای پرژین و بارش شبکه ای آفرودیت) به دو دوره تقسیم شد دوره اول 1992-1983 به عنوان دوره پایه و دوره دوم 2003-1994 به عنوان دوره ارزیابی. شاخص های راست آزمایی میانگین خطای مطلق و شاخص امتیاز مهارتی میانگین خطای مطلق بین مدل ها و شاهد در دوره ارزیابی قبل و بعد از اصلاح و ریزمقیاس نمایی به صورت فصلی در نرم افزار متلب برای تمامی پیکسل های استان خوزستان محاسبه شد. .نتایج حاکی از آن است که قبل از اعمال روش ریزمقیاس نمایی عامل تغییر (دلتا) مدل BCC-CSM1.1.Mدارای خطای کمتر نسبت به دو مدل دیگر بود و دو مدل دیگر از لحاظ میزان خطا تقریبا مشابه بودند. .بعد از اعمال روش دلتا مدل BCC-CSM1.1.M بهترین بهبود را از خود نشان داد و مدل های MPI-ESM-MR, MPI-ESM-LR به ترتیب در رتبه های دوم و سوم اهمیت قرار گرفتند. بنابراین بیشترین اعتماد بعد از ریزمقیاس نمایی به روش دلتا برای آینده تحت سناریوی RCP5.4 برای استان خوزستان به مدل BCC-CSM1.1.M اختصاص یافت. Manuscript profile -
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44 - بررسی تأثیر توزیع مکانی بارندگی بر سیلاب در حوضه آبریز سد بختیاری با استفاده از نرم افزار HEC-HMS
علیرضا نیکبخت شهبازیتوزیع ناهمگون مکانی و زمانی بارندگی در سطح کشور و تنوع آب و هوایی هر از چند گاهی در برخی نقاط باعث طغیان آب رودخانهها و وقوع سیلاب های بزرگی میگردد که از بابت خسارت های جانی و مالی، قابل توجه می­باشد. طراحی عملیات کنترل سیلاب نیازمند اطلاع دقیق از شرایط حوضه آبخیز Moreتوزیع ناهمگون مکانی و زمانی بارندگی در سطح کشور و تنوع آب و هوایی هر از چند گاهی در برخی نقاط باعث طغیان آب رودخانهها و وقوع سیلاب های بزرگی میگردد که از بابت خسارت های جانی و مالی، قابل توجه می­باشد. طراحی عملیات کنترل سیلاب نیازمند اطلاع دقیق از شرایط حوضه آبخیز مولد سیلاب بویژه واحدهای کوچکتر در حوضه‎های وسیع است. تعیین پتانسیل تولید سیل جهت تعیین کمی سهم هر زیر حوضه در تولید سیلاب پایین دست می تواند مبنای تعیین شاخصی به نام شاخص سیل خیزی هر زیر حوضه قرار گیرد. در این پژوهش تأثیر توزیع‎ مکانی بارش های بحرانی بر پتانسیل سیل‎خیزی حوضه آبریز سد بختیاری با استفاده از مدل HEC-HMS مورد تجزیه و تحلیل قرار گرفت، نتایج نشان داد که اثر توزیع مکانی بارندگی در شاخص سیل خیزی چشمگیر است، به ویژه هنگامی‎که با وقایع بزرگتر و با تعداد زیرحوضه‎هایی با مساحت بیشتر مواجه هستیم. از طرف دیگر تقدم مشارکت هر زیرحوضه در روندیابی بر دبی اوج خروجی از حوضه و نهایتاً روی شاخص سیل خیزی مؤثر خواهد بود. افزایش عمق بارندگی در زیرحوضه‎هایی که زمان تمرکز کمتری دارند تأثیر بیشتری بر روی شاخص سیل خیزی دارد. در زیر حوضه هایی که زمان تمرکز بیشتر و وسعت زیادتر است، توزیع ‎های مکانی مختلف تأثیر کمی بر شاخص سیل خیزی دارد. همچنین نتایج این تحقیق نشان داد که اگر اثر توزیع مکانی را در نظر نگیریم، شاخص سیل خیزی با افزایش مساحت زیرحوضه کاهش می‎یابد. Manuscript profile -
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45 - تحلیل فراوانی حداکثر بارندگی روزانه در گستره اقلیمی ایران
عباس احمدپور حسن فتحیان پرویز حقیقت جودر این تحقیق به منظور تحلیل فراوانی حداکثر بارندگی روزانه در نقاط مختلف ایران داده های مربوط به 40 ایستگاه سینوپتیک در طی یک دوره 40 ساله از سال 1352 تا 1391 مورد استفاده قرارگرفته است. این ایستگاه ها معرف اقلیم های مختلف ایران بر اساس طبقهبندی دومارتن می باشند. در ابت Moreدر این تحقیق به منظور تحلیل فراوانی حداکثر بارندگی روزانه در نقاط مختلف ایران داده های مربوط به 40 ایستگاه سینوپتیک در طی یک دوره 40 ساله از سال 1352 تا 1391 مورد استفاده قرارگرفته است. این ایستگاه ها معرف اقلیم های مختلف ایران بر اساس طبقهبندی دومارتن می باشند. در ابتدا داده ها به نرم افزار HYFA وارد شدند. نرمافزار مذکور دادهها را به هفت تابع توزیع آماری نرمال، لگ نرمال دو پارامتری، لگنرمال سهپارامتری، گامای دو پارامتری، پیرسون تیپ سه، لگ پیرسون تیپ سه و مقادیر حدی تیپ یک یا گمبل برازش میدهد. بنابراین دادهها به هفت تابع توزیع آماری فوق برازش داده شدند و مورد تحلیل فراوانی قرار گرفتند. نرم افزار HYFA پارامترها را بر اساس دو روش گشتاورها و حداکثر درستنمایی برآورد میکند. انتخاب بهترین توزیع برای تحلیل فراوانی حداکثر شدت بارندگی روزانه در هرکدام از ایستگاه های سینوپتیک با استفاده از آزمونهای میانگین انحراف نسبی و میانگین مربع انحراف نسبی صورت گرفت. نتایج نشان داد که داده های 29 ایستگاه از توزیع لگ نرمال سه پارامتری، پنج ایستگاه از توزیع گامای دو پارامتری، دو ایستگاه لگ نرمال دو پارامتری، و چهار ایستگاه دیگر از توزیع مقادیر حدی نوع یک یا گمبل تبعیت مینمایند. این مطالعه نشان میدهد که حداکثر بارندگی روزانه در اقلیم های مختلف ایران (مرطوب و خشک) می تواند با یک توزیع واحد تجزیه و تحلیل شود. از طرف دیگر در اقلیم های مشابه نمی توان از یک توزیع واحد برای تحلیل فراوانی حداکثر بارندگی روزانه استفاده کرد. Manuscript profile -
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46 - بررسی روند تغییرات زمانی و خصوصیات مکانی بارش و خشک سالی هواشناسی، در غرب کشور طی چند دهه اخیر
صفر معروفی حسین طبری علی آئینی حسین معروفیخشک سالی یکی از جدی­ترین مشکلات جوامع بشری و اکوسیستم­ها، در نتیجه تغییرپذیری اقلیمی است. این پدیده، سالانه موجب میلیاردها دلار خسارت در سطح جهان می­گردد و نسبت به دیگر بلایای طبیعی، مردم بیشتری را تحت تأثیر قرار می­دهد. در این تحقیق، روند تغییرات سری&sh Moreخشک سالی یکی از جدی­ترین مشکلات جوامع بشری و اکوسیستم­ها، در نتیجه تغییرپذیری اقلیمی است. این پدیده، سالانه موجب میلیاردها دلار خسارت در سطح جهان می­گردد و نسبت به دیگر بلایای طبیعی، مردم بیشتری را تحت تأثیر قرار می­دهد. در این تحقیق، روند تغییرات سری­های زمانی بارندگی و خشک سالی هواشناسی در ده ایستگاه واقع در غرب کشور، در دوره آماری 1384-1355 مورد بررسی قرار گرفته است. مقادیر شدت خشک سالی با استفاده از شاخص بارش استاندارد (SPI)، در مقیاس زمانی 12 ماهه محاسبه گردید. همچنین تحلیل روند داده­ها با استفاده از آزمون من-کندال و تخمین گر سِن انجام شده است. نتایج این تحقیق نشان داد که داده­های بارندگی و شدت خشک سالی، دارای تغییرات زیادی نسبت به میانگین در دوره مورد مطالعه بوده­اند. این تغییرات با افزایش خشکی به سمت شرق منطقه مورد مطالعه، فزونی یافته است. نتایج آزمون­ها نشان داد که سری­های زمانی بارندگی، دارای روند معنی­دار کاهشیمعنی­دار در ایستگاه­های سرپل ذهاب، بیجار، سنندج و سقز به ترتیب به میزان 99/7، 68/6، 51/5 و 03/5 میلی­متر در هر سال بوده است. همچنین شدت خشک سالی در ایستگاه­های کرمانشاه، سقز، سنندج و خرم­آباد در چهار دهه گذشته روند معنی­دار افزایشی داشته است. نتایج بدست آمده نشان داد که تمامی ایستگاه­های مطالعاتی، حداقل یک خشک سالی بسیار شدید را در دوره مورد مطالعه تجربه نموده­اند. Manuscript profile -
Open Access Article
47 - کاربرد تابع انتقال در مدل سازی بارش- تراز آب زیرزمینی در استان گلستان
یول امان ناظری نادر جندقی مجتبی قره محمودلو مجید عظیم محسنیﺁﺏﻫﺎی ﺯﻳﺮﺯﻣﻴﻨﻲ ﺍﺭﺯﺷﻤﻨﺪﺗﺮﻳﻦ ﻣﻨﺎﺑﻊ ﺁبی در کشور ایران بوده که ﻋﻤﺪﺗﺎ ﺗﺤﺖ ﺗﺄﺛﻴﺮ ﺍﻟﮕﻮﻫﺎی ﺑﺎﺭﺵ ﺩﺭ ﻳﻚ ﻣﻨﻄﻘﻪ ﻗﺮﺍﺭ ﺩﺍﺭﻧﺪ. در پژوهش حاضر از آمار 30 ساله بارش و تراز آب زیرزمینی در سه حوضه آبخیز گالیکش، رامیان و محمدآباد جهت مدل ­سازی بارش-تراز آب زیرزمینی استفاده شد. پیش ­ Moreﺁﺏﻫﺎی ﺯﻳﺮﺯﻣﻴﻨﻲ ﺍﺭﺯﺷﻤﻨﺪﺗﺮﻳﻦ ﻣﻨﺎﺑﻊ ﺁبی در کشور ایران بوده که ﻋﻤﺪﺗﺎ ﺗﺤﺖ ﺗﺄﺛﻴﺮ ﺍﻟﮕﻮﻫﺎی ﺑﺎﺭﺵ ﺩﺭ ﻳﻚ ﻣﻨﻄﻘﻪ ﻗﺮﺍﺭ ﺩﺍﺭﻧﺪ. در پژوهش حاضر از آمار 30 ساله بارش و تراز آب زیرزمینی در سه حوضه آبخیز گالیکش، رامیان و محمدآباد جهت مدل ­سازی بارش-تراز آب زیرزمینی استفاده شد. پیش ­بینی مقادیر تراز آب زیرزمینی با استفاده از داده ­های بارش برای 12 ماه آینده به کمک مدل تابع انتقال با استفاده از نرم­افزار SPSS انجام شد. در مرحله بعد اعتبارسنجی مقادیر پیش ­بینی شده با استفاده از شاخص ­های MAD، RMSE و MAPE مورد ارزیابی قرار گرفت. نتایج نمودار خودهمبستگی متقابل نشان داد در حوضه­ های گالیکش و محمدآباد بارش با سه ماه تاخیر بر تراز آب زیرزمینی تاثیر مستقیم گذاشته است، اما در حوضه آبخیز رامیان این تاخیر یک ماهه بود. همچنین مشخص شد مدل تابع انتقال در برازش مقادیر تراز آب زیرزمینی ماهانه در هر 3 حوضه آبخیز مورد بررسی عملکردی مناسبی داشته است. Manuscript profile -
Open Access Article
48 - کارآیی مدل برنامه ریزی ژنتیک در شبیه سازی فرآیند بارش- رواناب (مطالعه موردی : حوضه آبریز رودخانه خرم آباد)
حمیدرضا باباعلی زهره رامک رضا سپهوندپیش­بینی میزان دبی رودخانه یکی از مسایل مهمِ مهندسی منابع آب است؛ این موضوع از نظر برنامـه­ریـزی، مـدیریت، و سیاست­گذاری منابع آبی در راستای توسعة اقتصادی و زیستمحیطی به­ویژه در کشوری مثل ایران، با منابع آبی محدود اهمیت بسیار زیادی دارد. آگاهیازچگونگیارت Moreپیش­بینی میزان دبی رودخانه یکی از مسایل مهمِ مهندسی منابع آب است؛ این موضوع از نظر برنامـه­ریـزی، مـدیریت، و سیاست­گذاری منابع آبی در راستای توسعة اقتصادی و زیستمحیطی به­ویژه در کشوری مثل ایران، با منابع آبی محدود اهمیت بسیار زیادی دارد. آگاهیازچگونگیارتباطبینبارندگیورواناب حوضه­هایآبریزبخشجدانشدنیمطالعاتطرح­هایآبی می­باشد. فقدانداده­هایکافیبارش-رواناببهدلیلنبود ایستگاه­هایآبسنجیمناسب،اهمیتبه­کارگیری روش­های نامستقیم و الگوریتم­های فراکاوشیرابرایبرآوردمیزانروانابحوضه­های آبریزبیشازپیشنمایانمی­سازد. در این تحقیق از مدل برنامه­ریزی ژنتیک به­منظور شبیه­سازی فرآیند بارش-رواناب حوضه آبریز رودخانه خرم­آباد استفاده شده است و برای معرفیالگوهاوشناساییبهترینالگویحاکمبرماهیت جریان، با استفاده از توابع برازش و انجام فرآیندهای توسعه­ای و تکرار به منظور یافتن تعداد تکرار بهینه، همه داده­های دوره آماری به دو دسته آموزش و آزمایش(52% آموزش و 48% آزمایش) تقسیم شدند و برنامه برای 1000 تکرار اجرا گردید. همچنین جهت ارزیابی روابط حاصله از مدل شبیه­ساز، از شاخص­های جذر میانگین مربعات خطا (RMSE)،میانگین خطای مطلق(MSE) وضریب تعیین (R2) استفاده شده است. بررسی­های انجام شده حاکی از آن است که فرمول استفاده شده شماره 3 بیشترین انطباق را با داده­های مشاهداتی دارد. بنابراین پیشنهاد میشود جهت مطالعات بارش- رواناب این حوضه از فرمول ذکر شده استفاده گردد. نتیجه این تحقیق مدل برنامه­ریزی ژنتیک را یک روش صریح و دقیق برای پیش­بینی جریان رودخانه­ در حوضه آبریز رودخانه خرم­آباد پیشنهاد می­نماید. Manuscript profile -
Open Access Article
49 - The chaotic nature of monthly rainfall in the Tabriz under climate change
Rasoul Jani Mohammad Ali Ghorbani Abolfazle ShamsaiPopulation increase, changes in land usage and industrial activities' development have caused climate changes indifferent regions of the Earth. So studying these effects on rainfall process which is one of the most importantcomponents of water engineering studies. To co MorePopulation increase, changes in land usage and industrial activities' development have caused climate changes indifferent regions of the Earth. So studying these effects on rainfall process which is one of the most importantcomponents of water engineering studies. To considering ,extraordinary capabilities in chaos theory formodeling nonlinear and complex hydrological phenomena such as rainfall. In this study, monthly precipitation ofTabriz in the historical condition and climate change condition has been studied with this theory. For estimatelag time and phase state is using autocorrelation function and for chaos dimension applying correlationdimension method. Thus, the statistical period 1971-2000 as a historical period is chosen and the results of theLARS-WG model under two scenarios are (B1) and (A2) in three periods (2011-2030, 2046-2065 and 2080-2099) as future periods. Results show historical period data with the fractal dimension of 5/96 which has a goodchaotic nature. In scenario A2, three series of data, has chaotic nature and their fractal dimension is lower ofhistorical data while in scenario B1, The three periods have stochastic behavior. Manuscript profile -
Open Access Article
50 - Assessment of Islamshahr Watershed Environmental Reaction by Kinematic Wave Theory in GIS Base
Mahmood Zakeri NiriHydrologic problems are important in urban management. Hydrograph is an efficient tool in this management. In this paper behavior of synthetic and real watershed is studied. In first equations of Kinematic Wave Theory have coded in MATLAB and finally by achieved model i MoreHydrologic problems are important in urban management. Hydrograph is an efficient tool in this management. In this paper behavior of synthetic and real watershed is studied. In first equations of Kinematic Wave Theory have coded in MATLAB and finally by achieved model in MATLAB and use of GIS, reaction of watershed have assessment. In real watershed state, computed results have compared with a set of laboratory data (Observed Results). Comparison showed accuracy in regression. In second step, Islamshahr Watershed as a real watershed has assessment and by making isochrones, Time-Area curve was result by variety in rainfall intensity Manuscript profile -
Open Access Article
51 - Uncertainty analysis of HEC-HMS parameters using the GLUE methodology in Dez Dam watershed
mehdi komasi behrang beiranvandThis study represents the application of a generalized likelihood uncertainty estimation (GLUE) technique for automatic calibration of the well-known Hydrologic Engineering Center-Hydrologic Modelling System (HEC-HMS) model. For this purpose, the GLUE method was used in MoreThis study represents the application of a generalized likelihood uncertainty estimation (GLUE) technique for automatic calibration of the well-known Hydrologic Engineering Center-Hydrologic Modelling System (HEC-HMS) model. For this purpose, the GLUE method was used in calibration of the HEC-HMS model built for Dez Dam basin located in south-west of Iran. From the three selected events, first event was used for calibration and all events were used for uncertainty and sensitivity analysis using GLUE approach. Model calibration showed that the developed model is a suitable model for simulation of flood with R2 and Nash-Sutcliffe Efficiency of 0.9 and 0.887, respectively. Sensitivity analysis of the model based on the four parameters of the Green Ampt method indicated that model does not show the same sensitivity on the same parameter in different events. For instance, saturated hydraulic conductivity has the greatest influence on the model of event 1 and model of event 3 is more sensitive to saturation suction at the wetting front and porosity. Uncertainty analysis using posterior distribution describes the uncertainty of estimation after taking into account information provided by the various flood events. Overall, the GLUE analysis showed that there is a significant uncertainty associated with hydrological modelling that is due to multiple sources of errors. Also, this method can be used for calibration of hydrological models like HEC-HMS Manuscript profile -
Open Access Article
52 - Comparison of Soil Moisture Accounting model and Neuro-fuzzy for Rainfall-Runoff Modeling (Case study: Zola Chay watershed)
Ebrahim Yousefi MobarhanHydrological simulation of watersheds applies for estimating peak discharge and runoff volume from rainfall, flood routing in rivers and flood hydrograph analysis. The purpose of this study is application of soil moisture accounting (HMS SMA) and Neuro-fuzzy models in d MoreHydrological simulation of watersheds applies for estimating peak discharge and runoff volume from rainfall, flood routing in rivers and flood hydrograph analysis. The purpose of this study is application of soil moisture accounting (HMS SMA) and Neuro-fuzzy models in daily flow, The purpose of this study is application of soil moisture accounting (HMS SMA) and Neuro-fuzzy models in daily flow. runoff volume and hydrograph analysis of the simulated rainfall - runoff in the Zola Chay watershed. In this study after of Zola Chay watershed modeling with HEC-GeoHMS Extension, In this study after of Zola Chay watershed modeling with HEC-GeoHMS Extension. the model entered to HEC-HMS program and by parameters estimating of soil moisture accounting model, the rainfall- runoff simulation in other scales has been done. By analysis of time scales for calibration and optimization of HMS SMA model parameters we can claim that the monthly time scale rainfall - runoff simulation accurate than annual, seasonal, semiannual and annual time scales can be better than the other time scales of flow to estimate peak. Comparing the calibration and optimization soil moisture and Neuro-fuzzy methods revealed that fuzzy method can simulate rainfall- runoff relationship better than SMA model by best statistical coefficients (E= 0.76 and RMSE= 0.18). Manuscript profile -
Open Access Article
53 - Regional analysis and evaluation of the rain-gauge and hydrometric station networks of Jarrahi- Zohre Basin using discrete transinformation entropy
Seyed Morteza Tabatabae Seyed Amir Shamsnia Alireza ValipourAssess the quality of rainfall and stream flow information have an important role in improving the efficiency and correct their deficiencies. For an optimal monitoring network design, they should be reviewed periodically based on the information needs and future water r MoreAssess the quality of rainfall and stream flow information have an important role in improving the efficiency and correct their deficiencies. For an optimal monitoring network design, they should be reviewed periodically based on the information needs and future water resources development plans. In this study evaluates regional values of rain-gauges and stream-gauges in Jarrahi- Zohre basin using the discrete entropy. To determine the regional value of each station within a region, several information parameters, were calculated to identify essential rain gauge and critical area. Based on the obtained results, 39.7% of the area of the area does not have a rain-gauge station, while nearly 53% of the area of the area is in the class of lack, severe lack and lack of information exchange, and 40% of the area of the area is in the middle class. Therefore, the density of the 42 selected stations of the rain gauge network in Jarrahi - Zohre basin is not acceptable and it is necessary to seriously reconsider the distribution and layout of the rain-gauge stations in the area. Also, 21.16% of the area of the area does not have a water measuring station. While more than 5.7% of the district area is in the class of deficiency, severe deficiency and lack of information exchange, and more than 73% of the area of the district is in the middle, upper middle and surplus class. Therefore, the density of the 16 selected stations of the water measurement network is optimal and other active water measurement stations can be removed from the monitoring network of the area. Manuscript profile -
Open Access Article
54 - Determined of Rainfall Erosivity Indices (EI30, Lal, Hudson and Onchev) for Namak Lake Basin
Z.T. Alipour M.H. Mahdian S. Hakimkhani M. SaeediIn this research the indices EI30, AIm,‎ KE>1‎ as well as P/√t‎ were determined for 16 pluviograph as well as for 3 Namak Lake Basin nearby stations. Regression relationships were established between the dependent variables of EI30, AIm, KE>1&lrm MoreIn this research the indices EI30, AIm,‎ KE>1‎ as well as P/√t‎ were determined for 16 pluviograph as well as for 3 Namak Lake Basin nearby stations. Regression relationships were established between the dependent variables of EI30, AIm, KE>1‎ as well as P/√t‎ Indices and other easily accessible rainfall indices of: fournier, modified fournier, maximum monthly rainfall, maximum daily rainfall, standard deviation of monthly and annual rainfall as well as pluviometer site elevations. This made the establishment of appropriate relationships between rainfall intensity dependent indices and the dependent variable of rainfall intensity (at stations where intensity was non-existent) possible. In the next step, the indices as well as easily accessible rainfall data from pluviograph stations were exploited to find out EI30 ,AIm ,‎ KE>1‎ as well as P/√t‎ indices, while using the previously obtained regression relationships. Manuscript profile -
Open Access Article
55 - Response of Durum Wheat Genotypes to Different Planting Dates and Plant Densities under Dryland Conditions
Saeid Ghazvineh Ali Reza Valadabadi Abdol Vahab Abdolahi Saeed Seyfzadeh Hamid Reza ZakerinThe present study was conducted to investigate the response of durum wheat cultivars to different planting dates and densities under rainfed conditions during the years 2014-2016 in Sararood, Kermanshah, using a split plot factorial experiment based on randomized comple MoreThe present study was conducted to investigate the response of durum wheat cultivars to different planting dates and densities under rainfed conditions during the years 2014-2016 in Sararood, Kermanshah, using a split plot factorial experiment based on randomized complete block design with four replications. Three durum wheat genotypes (SAJI, BCR and STJ) with three sowing dates, prior to effective rainfall (the amount and time of effective rainfall were 33.2 and 34.5 mm, and 26 October, and 5 November for two years of experiment, respectively). 15 days after effective rainfall and 30 days after effective rainfall were evaluated for four densities of 250, 350, 450 and 550 plant per square meter. Traits like number of spikes per square meter, 1000 kernel weight, seed and biological yield, harvest index and absorbed radiation percentage were measured. The results of mean comparisons of simple effects showed that the number of spikes per square meter in the planting date before rainfall was more effective than two other planting dates. Biological yield and absorbed radiation percentage were 26.9 and 12.9 percent higher respectively in second year of experiment as compared to the first year. Comparison of interactions means showed that STJ genotype under 250 seeding density and 15 days sowing date after effective rainfall, produced highest 1000 kernel weight, while SAJI cultivar at 550 seeding density and planting date before effective rainfall showed the highest kernel yield. The SAJI cultivar showed highest biological yield under 450 seeding density and planting date before effective rainfall. For all three genotypes, the highest percentage of radiation absorption was observed when sowing date used before rainy season using 450 and 550 seeding densities. In this study all genotypes showed the highest traits values at first planting date and under 450 seeding density. The highest values of protein and chlorophyll content were observed using 350 seeding density. Manuscript profile -
Open Access Article
56 - Spatial analysis and modeling the relationship between atmospheric action centers with widespread anomalies precipitation of Iran
Hosain Mohammadi Faramarz Khoshaghlagh ghasem azizi Mohammad Amin HeidariVariability is one of inherent properties of the climate system. In addition to the dynamic nature, the climate system is extremely intertwined nature also, so that its components interact with each other and eventually they change each other.. In general, the climate o MoreVariability is one of inherent properties of the climate system. In addition to the dynamic nature, the climate system is extremely intertwined nature also, so that its components interact with each other and eventually they change each other.. In general, the climate of a region or geographic location is controlled by various factors, including Atmospheric Action Centers (AAC's). AAC's behaviors have an effective role in short and long term changes in weather and climate conditions and also their components. AAC's can change the climate system. A climatic index is defined here as a critical value that can be used to describe the states and the changes in the climate system. Changes on climate are much slower than on the weather, that can change strongly day by day. Each climatic index is based on certain parameters and describes only certain aspects of the climate, so there are a variety of climate indices that have been defined and examined in numerous publications. For each climate index there is a defining equation that uses the so-called climate elements. These are measurable parameters that influence the properties of the climate system, primarily, for example, atmospheric parameters such as air pressure, air temperature, precipitation and solar radiation, but also non-atmospheric parameters such as sea surface temperature or ice cover. Manuscript profile -
Open Access Article
57 - Analysis of Synoptic Patterns of the Two Heaviest Rainfall Events in Zayandeh Rood Dam Basin
Shahideh Dehghan Amir Gandomkar Alireza AbbasiPrecipitation is one of the most important climatic elements, and its importance increases especially when heavy rains occur. Investigating rainfall or heavy rainfall in a region requires analysis of synoptic patterns. This research was conducted with the aim of investi MorePrecipitation is one of the most important climatic elements, and its importance increases especially when heavy rains occur. Investigating rainfall or heavy rainfall in a region requires analysis of synoptic patterns. This research was conducted with the aim of investigating the heavy rains in the catchment area of Zayandeh Rood Dam. For this purpose, the daily rainfall data of Kohrang, Fereydon Shahr, Shahrekord, Daran, Pol Zaman Khan, Farrokh Shahr, Chadegan and Saman stations during the statistical period of 1958-2019 were used. After examining the data, two rainfall events on 7/1/2004 and 12/3/2005, which were heavy rains (rainfall above 20 mm) in the study area, were selected and their co-occurrence patterns were analyzed. The data related to geopotential height of three levels of 500, 700 and 850 hectopascals was obtained from the NOAA site and its maps were drawn in Arc Gis software. The obtained results showed that heavy rains occur in the studied basin when cold air in higher latitudes moves to lower latitudes and obtains the necessary moisture over the Red Sea and the Mediterranean. When the trough axis is located in the eastern Mediterranean and there is a lot of humidity, it causes heavy rains in the studied area. In general, it can be stated that the heaviest rains in the studied area occur in March and the Mediterranean and Sudanese systems cause heavy rains in this area. Manuscript profile -
Open Access Article
58 - Modeling and Predicting the Risk of Occurrence of Flood Zones Due to Rainfall Under Climate Change Conditions case study: Gorganrood watershed
Abdolhafez Panahi Gholamreza janbazghobadi Sadroddin Motevalli shahryar khaldi.floods are known as one of the most important natural disasters. In practice, floods are one of the most devastating weather disasters in the world, both in terms of casualties and financial losses. The purpose of this study is to measure and evaluate the changes in fl More.floods are known as one of the most important natural disasters. In practice, floods are one of the most devastating weather disasters in the world, both in terms of casualties and financial losses. The purpose of this study is to measure and evaluate the changes in flood zones using the weighting technique in the GIS environment. The method of the present study, according to the nature of the problem and the subject under study, is descriptive-analytical and applied studies. With emphasis on quantitative methods, in the present study, changes in flood zones in Gorganrood watershed based on the use of meteorological station information (synoptic) with a 30-year statistical period (1989 to 2018), land use, vegetation, topographic moisture index Slope, altitude, land lithology, distance from river, river density, erosion, soil science, runoff, simulated precipitation data from LARS-WG model have been modeled and estimated. The general kriging method with the lowest mean estimation error (0.004) and the square root mean error of 82.23 is the best method for interpolation in this study. Also, in combining fuzzy analysis methods with hierarchy to determine the expected estimate, both methods had higher estimates than expected. Findings showed that 800 mm sub-basin of Normab basin in the central part of Maderso, Yale Cheshmeh and Qarnaveh basins in the northeast of Gorganrood watershed with the amount of 500 to 700 mm and the northern parts of Mohammadabad and Ghorchai basins with the amount of 300 mm. Manuscript profile -
Open Access Article
59 - Improving hybrid modeling using an efficient model for rainfall forecasting
Laleh ParvizLow-precision rainfall forecasting leads to significant losses in various sectors such as agriculture and the environment. In this regard, the effect of support vector regression (SVR), gene expression programming (GEP) and group data modeling (GMDH) models on improving MoreLow-precision rainfall forecasting leads to significant losses in various sectors such as agriculture and the environment. In this regard, the effect of support vector regression (SVR), gene expression programming (GEP) and group data modeling (GMDH) models on improving the performance of the hybrid model was examined, which is based on station rainfall data. Urmia and Isfahan with two different climates were used in the period 1964-2019. In nonlinear section modeling, the third combination with the linear section combination, residuals and observational data in the previous time step had less error, for example in Isfahan station, the rate of RMSE reduction from combination 1 to 3.73 / 62 And the rate of SMAPE reduction from 2 to 3 was equal to 62.79%. The hybrid model had better performance than the stochastic model, so that the amount of RMSE from the stochastic model to the hybrid model with SVR, GEP and GMDH at Urmia station decreased by 79.46, 68.34 and 75.77%, respectively. . The gene expression programming model was less accurate than the other models studied (in Urmia station, the rate of UII reduction from GEP to SVR model was 32.5 and 15.62%, respectively, and in Isfahan station, the rate of increase in Nash coefficient was Sutcliffe from GEP to GMDH was 22.38). The amount of Nash-Sutcliffe coefficient in all three models in Urmia station was higher than Isfahan (the average rate of decrease in Nash-Sutcliffe coefficient from Urmia station to Isfahan was 6.22%) but the value of coefficient in both stations is within acceptable range. Therefore, choosing an efficient model with the right combination in nonlinear modeling will have a significant effect on increasing the efficiency of the hybrid model. Manuscript profile -
Open Access Article
60 - Revelation and Comparative of Rainfall and Discharge Cycles of QalehRoudkhan and Navroud Basins
مهرداد رمضان پورHumans have been the main cause of climate change, ignoring the laws of nature and the lack of understanding of the environmental issues associated with it. The Clear and hide cycles of climate change are also affected by climate change. The appearance and occurrence of MoreHumans have been the main cause of climate change, ignoring the laws of nature and the lack of understanding of the environmental issues associated with it. The Clear and hide cycles of climate change are also affected by climate change. The appearance and occurrence of these fluctuations can play an important role in the creation of environmental crises and their identification in environmental planning. Therefore, in the present study, hide, slow and gradual cycles for rainfall and discharge time series with a statistical period of 38 years (1966-2005) at seasonal scale in both Navourood and QalehRudkhan basins in Guilanprovince through spectral analysis technique and analysis of chronographs at 95% confidence interval was identified and compared. The results of this study indicate that in Navroud basin for both parameters, cycles are significant and follow different sinusoidal cycles. However, the non-sinusoidal cycle has not been seen in the QalehRoudkhan basin. The change of discharge in the Navaroud basin is more than rainfall, but the non-sinusoidal cycle (trend) of discharge in the GhalehRudkhan basin is more apparent than seasonal rainfall. Manuscript profile -
Open Access Article
61 - Synoptic analysis of devastating floods July 2015 in north of Iran
Mahmoud Ahmadi Farzaneh JafariDreadful and torrential precipitations in the summer cause heavy damages in the sections of constructive and agricultural installation in different regions of the country because of their unexpected. In this research we proceed to synoptic and thermodynamic of torrentia MoreDreadful and torrential precipitations in the summer cause heavy damages in the sections of constructive and agricultural installation in different regions of the country because of their unexpected. In this research we proceed to synoptic and thermodynamic of torrential flooding of 28 to 31 july2015 in the half north, west and central of the country. First with using territorial stations data the precipitation of under studied stations analyzed and then with using upper atmospheric data and tracing the related maps, precipitations analyzed. The results showed that spreading the black sea high pressure on north half of the country and penetrating the Warm low pressure of Persian Gulf-Pakistan from south, meanwhile, northern flowing cause severe gradient pressure in the sea level. In the middle levels stretching the trough axis from central Asia till south of Iran cause severe ascending of air. Analyzing the omega maps on Iran indicates the settlement of maximum negative omega in north of Iran. Also analyzing of moisture advection showed that in the levels of 1000 and 850HPA, the black and Caspian seas are the sources of supplying moisture. But in the levels of 700 and 500 HPA, the Oman and Arab Sea and India peninsula has the main rule in transferring the moisture on the studied region.The point worthy of attention is that the jet stream located only above the level of 300 hpa and upper the latitude of 38 northern degree and out of the occurrence boundary of supper heavy precipitation of ending days in July 2015.And it's impact was indirect which caused offloading the warm and humid air to the through and consequently strengthen the instability. Manuscript profile -
Open Access Article
62 - The Effect of Biomechanical Operations on Rangeland Vegetation (Case Study: Rangelands of Abarkooh, Yazd)
saeede sedghiExecution of rainfall storage operationsis is one of the most important methods of improving and restoring rangeland vegetation. This study was conducted to investigate the effect of rainfall storage on vegetation factors in winter rangelands of Abarkooh, Yazd. The succ MoreExecution of rainfall storage operationsis is one of the most important methods of improving and restoring rangeland vegetation. This study was conducted to investigate the effect of rainfall storage on vegetation factors in winter rangelands of Abarkooh, Yazd. The success of biomechanical operations was evaluated through the analysis of vegetation factors including canopy cover, production, regeneration, and density in four treatments: control, pitting, contour furrows, and crescent ponds. The sample was selected through random – systematical method of sampling with the establishment of transects and plots. One-way between groups ANOVA was run in order to analyze the data. The results showed that the studied factors had a significant difference at the statistical level of one percent (P <0.01). So that in the crescent ponds method Percentage of canopy, production, density and regeneration of plant species had the highest value with 8.5, 39.25, 6.6 and 3.9, respectively, in comparison with the other two methods. These factors did not show a significant difference with the control in contour furrows and Pitting methods. The results of this study showed that crescent ponds had a greater effect on restoration and increase of vegetation compared with contour furrows meter and pitting methods. Manuscript profile -
Open Access Article
63 - Investigating the effects of rainfall and drought changes on Zarivar Lake ecosystem
Amir Gandomkar Nader Fallah Alireza AbbasiWatersheds and wetlands are the most biologically diverse ecosystems on Earth due to the presence of water. They are spread all over the planet and play an important role in the water cycle. Due to the importance of this issue, the present study was conducted to investi MoreWatersheds and wetlands are the most biologically diverse ecosystems on Earth due to the presence of water. They are spread all over the planet and play an important role in the water cycle. Due to the importance of this issue, the present study was conducted to investigate the changes in precipitation and drought in Zarivar Lake and their effects on the lake ecosystem. In this regard, the annual rainfall statistics of Zarivar Lake station during the statistical period of 1397-1397 has been used. After normalization of the studied data using Anderson Darling test, it was found that they have an abnormal distribution, so the non-parametric Mann-Kendall test was used to calculate their trend. Then SIAP index was used to study the lake drought. The results show an increasing trend of precipitation during the statistical period under study. Studies on drought also showed that the years 1999 to 2003 were part of the dry years of the lake. During the period 1383-1387, the conditions were almost normal. Wet conditions have prevailed on the lake since 2008. The year 1397 also has very wet conditions. Due to the fact that 1397 was a very rainy year, but it will cause overflow and flow of water in Zarivar river and also strengthen and nourish groundwater in the southern plain of the lake and increase water quality along the river and play a significant role in reviving and strengthening the lake ecosystem. has it. Manuscript profile -
Open Access Article
64 - Zonation of rainfall erosivity strength; using Fournier method and some interpolation techniques (a case study of Ghazvin province)
حسن ahmadiAbstract In this study rainfall erosivity in Ghazvin province has been modeled and estimated through the application of Fournier model and based on a 20-year statistical period (1368-1388) of meteorological bureaus (synoptic, climatology and rain gauge) and Regional wa MoreAbstract In this study rainfall erosivity in Ghazvin province has been modeled and estimated through the application of Fournier model and based on a 20-year statistical period (1368-1388) of meteorological bureaus (synoptic, climatology and rain gauge) and Regional water organization. To generalize point data of erosivity strength ratio in Fournier model to the surface, in Ghazvin province, Kriging and IDW methods have been used. In addition, to evaluate interpolation methods, cross validation and RMSE criterion have been employed. Accordingly, IDW method was identified to be more appropriate, due to the less error in mean chi-square (6/59) than Kriging method (7/23). Also, Variogram with exponential model was used as the proper model for fitting. Modeling and evaluation of rainfall erosivity in Ghazvin province were performed by location analysis function of Geographic Information System and GS+ software. The data indicate that north and northeastern regions and some parts in the southwest of the province, with minimum/maximum rainfall of (216.1- 776.9) and (205.2- 751) respectively, have the highest rainfall erosivity ratio. These changes could be influenced by rain distribution patterns, the amount of rainfall, and the topographical characteristics of the region. Ultimately, 4 different regions with insignificant, low, medium and high erosive ratios were distinguished in Ghazvin province. Manuscript profile -
Open Access Article
65 - Comparison of Runoff and Suspended Sediment Concentration in Various Work Units of Lavij Watershed
M.R Javadi tabalvandani S.A Gholami جعفر DastoraniIn this study Run off and sediment generated from rain fall simulator was investigated in lavij watershed. In this order٬slope-Lithology- geomorphology and Land use maps were intersected and then, work units map was prepared. Then, in each Work unit's tree run off and s MoreIn this study Run off and sediment generated from rain fall simulator was investigated in lavij watershed. In this order٬slope-Lithology- geomorphology and Land use maps were intersected and then, work units map was prepared. Then, in each Work unit's tree run off and sediment sampling was created by Rainfall simulator. Results show that٬ the Maximum potential of runoff generation was approved ٬in work unit of number fifteen with range land and 15-30% slop, also the Maximum potential of Sediment suspended production was approved ٬in work unit of number teen with range land and 15-30% and shemshak formation. The minimum run off and suspende sediment production were approved in work unit number one with range land and 12-15% and Elika formation. Manuscript profile -
Open Access Article
66 - Prediction Probable Flood and Maximum precipitation Using Poldukhtar Basin Suffered partial Series
مهدی Mehdinasab تقی Tavoosi رضا MirzaeiFloods are natural phenomenon that human societies have accepted it as an inevitable event but the event size and frequency of flooding is caused by several factors That is, depending on climatic conditions, natural and geographical each region changes. Annually in diff MoreFloods are natural phenomenon that human societies have accepted it as an inevitable event but the event size and frequency of flooding is caused by several factors That is, depending on climatic conditions, natural and geographical each region changes. Annually in different parts of the world, many people's lives and properties due to flood risk falls And millions of tons of precious soil are destroyed by floods. One of the world is a flood natural disaster losses Bartryn. Statistical analysis has shown that about 70 percent of flood damage is caused by natural disaster in Iran This study estimated the a probable flood and maximum precipitation using Poldukhtar suffered minor series is action. The number 20 Heavy rainfall 24Hours over 40 millimeters The number 30 seals with more than 500 cubic meters per second was chosen discharge. Selection criteria for floods had chosen the first seal is attached to the previous flood. Thus, the interval between Two flood peaks from each other, must be at least 3 times the amount of time discharge began to reach the stage of the flood hydrograph peak flow needs. Secondly, the amount of discharge after the first flood and before the second flood in less than one third flood peak is reached first.The series detailed method to estimated the flood discharge and The maximum sustained 24-hour rainfall return periods of 2, 5, 10, 25, 50, 100 and 200 years has been And the results showed that each year, probably 99.99 percent slapped with a flow rate 606.32 cubic meters and a 24-hour precipitation amount of 43.07 millimeters Poldukhtar happening in theBasin Manuscript profile -
Open Access Article
67 - Flood warning system established by the integrated management of hydrological and hydraulic modeling
وحید Yazdani احسان Behjati عاطفه ArfaAbstract Study more about the different points of view Hydrometolojy flood drainage systems and catchment model analysis of rainfall, runoff and flood designated area according to hydrological and hydraulic retention basins, not only financially, but also t MoreAbstract Study more about the different points of view Hydrometolojy flood drainage systems and catchment model analysis of rainfall, runoff and flood designated area according to hydrological and hydraulic retention basins, not only financially, but also the legal and the pre warning system to predict and help the decoder is represents the flooding. The purpose of this study is to provide an appropriate mechanism to establish flood warning system hydrological model HEC-HMS and HEC-RAS hydraulic model for the catchment dam is Garmi Chay. After restructuring the data in hydrological studies, flood frequency analysis, maximum a day at selected stations has been distributed to all stations, the three-parameter normal distribution. Applying the ratio of the maximum instantaneous flood peak flood one day, maximum instantaneous flood levels with return periods Garmi Chay River at the dam site Garmi Chay was calculated. The model calculations show that the contribution of the sub-basin outlet flood peak flows sub watershed is not necessarily proportional to the sub basin with high peak flows are not necessarily more effective flood basin outlet. Based on the results pre alerts dam hot tea in Group C (no more than 3 to 6 hours) floor was packed. Manuscript profile -
Open Access Article
68 - FLOOD FORCASTING USING HEC-HMS (CASE STUDY: MAROON CATCHMENT-Eidenak Hydro clammology station )
Mohammad AMIN Gandomi Babak sheheni darabiThe Maroon River, one of the Jarahi River head waters, is located in Maroon Catchment and the upstream of Behbahan City. Maroon Dam with maximum volume of 1193 MCM was built on this river by Khuzestan Water & Power Authority [1]. The dam prevents from seasonal high MoreThe Maroon River, one of the Jarahi River head waters, is located in Maroon Catchment and the upstream of Behbahan City. Maroon Dam with maximum volume of 1193 MCM was built on this river by Khuzestan Water & Power Authority [1]. The dam prevents from seasonal high flood damages and saves large amounts of water for agriculture consumptions. The river has flash floods with high peaks, so it seems that flood control and management are cases of high importance in this catchment and it's necessary to have information about flood volume for flood management, downstream programming and consumption estimation in a water year. Therefore, runoff data were calibrated based on the real precipitation data, using HEC-HMS Rainfall-Runoff Model and Schneider Method. Considering 12 observed floods in the past years, observed and calculated runoff values were compared and the best parameters were calculated for initial & final soil infiltration and time of concentration &Good results from this review were obtained Manuscript profile -
Open Access Article
69 - Variations Trend Evaluation of Rainfall Using Mann-Kendall and Linear Regression in Khuzestan Province
mostafa ghasabfeiz hossein eslamiRainfall trend could be evidence of climate change. There are different ways to review trends in rainfall time series are divided into two categories: statistical parametric and non-parametric. Linear regression method is from statistical and most common non-parametric MoreRainfall trend could be evidence of climate change. There are different ways to review trends in rainfall time series are divided into two categories: statistical parametric and non-parametric. Linear regression method is from statistical and most common non-parametric method is Mann-Kendall. Considering the period of 33 years from 1980-81 until 2013-14, at 47 meteorological stations in Khuzestan province. Results showed that the slope of the regression line can vary from -13 to 0.8. More weather stations are a negative trend in the amount of rainfall and only Abdolkhan and Polezal stations have a significant positive trend. Mann-Kendall test for the existence of trends in rainfall at a confidence level of 5% was found that the negative trends are more stations and rainfall in the province is declining. Only stations of Polezal, Chamnezam, Harmaleh, Abdolkhan and Arabhasan have positive trend and Batvand shoor has Z value equal to zero with rainfall amounts are fixed in the period. Although all stations have a positive or negative trend, but only three stations Sousan, Sepid dasht sezar and Mollasani are significant at a confidence level of 5%. Although it cannot be concluded that climate change has occurred but due to the fact that most stations are reduced rainfall trend is alarming. Manuscript profile -
Open Access Article
70 - Evaluation of spatio-temporal variations of rainfall erosivity index using cokriging method in Khouzestan province
hossein eslamiRainfall erosivity is the ability of rain to separate soil particles and has a high correlation with soil erosion. The aim of this study was to investigate the temporal spatial variations of rainfall erosivity using the EI30 index. In this study, EI30 index was calculat MoreRainfall erosivity is the ability of rain to separate soil particles and has a high correlation with soil erosion. The aim of this study was to investigate the temporal spatial variations of rainfall erosivity using the EI30 index. In this study, EI30 index was calculated for different months and seasons in 9 recording rain gauge stations in Khouzestan province. Then, using regression relationships between EI30 index and other easily accessible rainfall specifications and indices in rain gauge stations, the values of EI30 index for 65 rainfall stations were estimated. In order to prepare the monthly and seasonal rainfall erosivity map, the point data of EI30 index in 74 recording raingauge and non-recording raingauge stations were interpolated using Cockriging geostatistical method. According to the prepared maps, the highest amounts of monthly and seasonal rainfall erosivity are in the east and north of Khouzestan and the lowest amounts of rainfall erosivity are in the south and west of Khouzestan province. On average, the highest monthly rainfall erosivity index occurs in December with a value of 292 Mj.mm.ha-1.h-1 and the highest seasonal erosion index occurs in winter with a value of 576 Mj.mm.ha-1.h-1 and the value of this index is zero for summer. Manuscript profile -
Open Access Article
71 - Effect of Acid Precipitations on Formed Soils Infiltration in Gachsaran formation
hamzah saeediyanEach soil mass is composed of solid grains with different sizes and empty spaces that allow empty spaces to be moved to water from a high-energy point to a lower-energy point, which creates the permeability of the soil. In this study, in order to determine the most impo MoreEach soil mass is composed of solid grains with different sizes and empty spaces that allow empty spaces to be moved to water from a high-energy point to a lower-energy point, which creates the permeability of the soil. In this study, in order to determine the most important factors affecting soil permeability, compared to acidic rainfall in the slope main aspects of Gachsaran formation, a part of the gypsum mountain basin of Izeh City with an area of 1202 hectares was selected. This study, In order to determine the relationship between the infiltration rate by rainfall simulator with some soil physical and chemical properties such as percentage of gravel, clay, silt, sand, acidity, electrical conductivity, moisture, calcium carbonate, and organic matter and sodium were performed in different slopes of Gachsaran formation. The most important factors influencing the penetration rate were identified by multivariate regression. The regression models showed that generally, in all slope main aspects in Gachsaran formation in rainfall with distilled water, the chemical characteristics of the most important role in increasing and decreasing the permeability and in precipitation with the acidity 5, the chemical characteristics of the soil are the most important role in increasing and decreasing the level of permeability, but with increasing the concentration of acidity to 4, the physical and chemical characteristics of the soil have an equal role in increasing and decreasing. Manuscript profile -
Open Access Article
72 - Modeling Ghotour-Chai River’s Rainfall-Runoff process by Genetic Programming
Mina Ruhnavaz Abdolreza Hatamlou -
Open Access Article
73 - Statistical Analysis of Annual Temperature Kermanshah Synoptic Station and it Relationship with Rain and Humidity(1951-2005)
Reza Khoshraftar Hamid AkbarieTemperature is one of climatic components which has significant role over other climatic elements. Analysis of its change trend in environment planning is import solution for many environment problems. In this research, in order to analyze the trend and temperature cond MoreTemperature is one of climatic components which has significant role over other climatic elements. Analysis of its change trend in environment planning is import solution for many environment problems. In this research, in order to analyze the trend and temperature condition in Kermanshah, the average and monthly temperature applied during the statistical period (1957-2005). There for by using the statistical parameters and SPSS software, various kind of diagram is drawn and analyzed. The result from statistical analysis indicated that annual temperature of Kermanshah station ranged from 14/46 to 14/53. Based on test, although the temperatures of Kermanshah have fluctuated toward the average temperature in some years, but generally it indicates the normal trend. Analyzing the probability of temperature occurrence in different level based on webule’s experimental formula and table method indicated that, with 90-80 percent possibility, annual temperature of Kermanshah will be between 15 – 15/5 . Manuscript profile -
Open Access Article
74 - The likely Effect of Precipitation Change on Runoff, Case Study: Jajrood River
alireza shakiba batol bahak zari monavarianOne of the likely effects of climate change is to study the effect of rainfall variations in runoff values Accordingly, in this research catchment namely Jajrood was selected. First, rainfall and runoff data using homogenity test was studied. Then, a statistical period MoreOne of the likely effects of climate change is to study the effect of rainfall variations in runoff values Accordingly, in this research catchment namely Jajrood was selected. First, rainfall and runoff data using homogenity test was studied. Then, a statistical period was chosen . To study the data distribution, many statistical indices such as mean, variance, standard diviation,…were calculated. Wet and dry periods was extracted based on a moving average method . Finally order in make a significant correlation between rainfall and runoff , the correlation coefficient and regression equation were calculated. The result of the research showed that there could be a some periods of dry and wet in the study area , with more lasting dry period. The result also indicated that there is a rather significant correlation between rainfall and runoff . The correlation coefficient and R2 for Jajrood catchment are 0.8389 & 0.7039 respectively. Manuscript profile -
Open Access Article
75 - Analysis of Precipitation Climate and Evapotranspiration in Kerman of Iran
Shahram Karimi-Googhari -
Open Access Article
76 - -Impact of Climate Variability on Cool Weather Crop Yield in Ethiopia
آرگا آدم بلای کاسا دگی گوشو ماجالیوا موانجالوThe research examined effect of climate variability on yield of the two dominant cool weather cereals (wheat and barley) in central highland and Arssi grain plough farming systems of Ethiopia using eight round unbalanced panel data (1994-2014). The stochastic frontier m MoreThe research examined effect of climate variability on yield of the two dominant cool weather cereals (wheat and barley) in central highland and Arssi grain plough farming systems of Ethiopia using eight round unbalanced panel data (1994-2014). The stochastic frontier model result revealed that production inputs for producing wheat and barley in the two farming system had significant effect. Crop season rainfall increment had negative and significant effect on technical efficiency of smallholders to produce wheat as to the model result. Technical efficiency of two crops responded differently for cropping season rainfall variability, in which wheat had negative and significant interaction with it while barley had positive. Given this, cropping season temperature had significant and positive effect on technical efficiency of both wheat and barley. Having this into account, yield of the two crops responded similarly for changes in production inputs like working capital, human labor and fertilizer. In general, rainfall inconsistency at the different stages of the production period had strong effect on yield of the two crops. Given this, the study forwarded an assignment to plant scientists in order to have further investigation on how the two crops responded differently to temperature variability. Manuscript profile -
Open Access Article
77 - اثر تغییرات بارندگی بر متغیرهای اقتصادی با استفاده از مدل تعادل عمومی
زینب معین الدینی حمید محمدی حسین محرابی بشرآبادیاقتصاد ایران به متغیرهای اقتصادی بسیاری وابسته است که در رشد و توسعه آن کشور نقش دارند. از طرفی، بارندگی یکی از عوامل مهم آب و هوایی است که روی برنامه های مهم اقتصادی از جمله بخش کشاورزی موثر است. تغییرات بارندگی بر متغیرهای اقتصادی بسیاری تاثیرگذار اس Moreاقتصاد ایران به متغیرهای اقتصادی بسیاری وابسته است که در رشد و توسعه آن کشور نقش دارند. از طرفی، بارندگی یکی از عوامل مهم آب و هوایی است که روی برنامه های مهم اقتصادی از جمله بخش کشاورزی موثر است. تغییرات بارندگی بر متغیرهای اقتصادی بسیاری تاثیرگذار است که در این مطالعه به ارزیابی بعضی از آن­هاپرداخته شده است. هدف از این تحقیق ارزیابی شوک­های بارندگی بر متغیرهای اقتصادی با استفاده از روش تعادل عمومی است که این شوک­ها شامل؛ بهترین سناریو، برای بیشترین بارندگی، بدترین سناریو برای کمترین بارندگی و سناریوی نرمال برای متوسط بارندگی می­باشند. یه منظور ارزیابی این تغییرات بر بخش کشاورزی، مجموعه ای از کالاهای تولیدی بخش کشاورزی به صورت جداگانه مطرح شد و برای سایر بخش­های اقتصادی با هم تجمیع گشت. نتایج تحقیق نشان داد که تولیدات بخش کشاورزی در بهترین سناریو به میزان 14 درصد افزایش یافته است. در بدترین سناریو میزان مصرف همه کالاها کاهش، قیمت همه کالاها به جز بخش صنعت افزایش و سرمایه­گذاری خصوصی و دولتی نیز تغییر یافته است. Manuscript profile -
Open Access Article
78 - ;;
Toyin Ajibade Jubril Animashaun -
Open Access Article
79 - Sensitivity Analysis of Meteorological Parameters in Runoff Modelling Using SWAT (Case Study: Kasillian Watershed)
Mohsen Ghane Sayed Reza Alvankar -
Open Access Article
80 - Synoptic analysis of Caspian torrential rains, Case Study: Winter floods in 2012 Noushahr
A. Mohammadi M. Salighe E. Hamidy A. HesamyTorrential rains in the southern Caspian Sea, has been of interest for researchers and different solutions have been offered. The analysis shows that thesuggested mechanisms are all derived from a single model. These theories are different only in appearance. This singl MoreTorrential rains in the southern Caspian Sea, has been of interest for researchers and different solutions have been offered. The analysis shows that thesuggested mechanisms are all derived from a single model. These theories are different only in appearance. This single model is the basic mechanism of the Caspian Sea rainfall in autumn and winter. Torrential precipitation more occurs in autumn and less in winter. In this paper, winter floods in Noushahr city in 2012 have been studied. By posing different theories governing the precipitation of the Caspian Sea, next to one another, the pattern was introduced for the torrential rains. Results indicated that the floods were caused by the passage of low pressure systems from the North Caspian Sea. Low pressure cold front has passed over Noushahr on 11 November 2012. The cold front on 12 November 2012, located near the center of Iran, at 35 latitude. With the influx of cold air behind the cold front caused floods in Noushahr city. Cold advection over the sea caused too much moisture absorption by the air. The results also showed that the ridge of high pressure that immigrated from the north Mediterranean had important role in the passage of the cold front is Noushahr city. The ridge is moving cold front to lower latitude finally passes through the north of Iran. The cause of ridge formation was cold air advection on the Caspian Sea. Manuscript profile -
Open Access Article
81 - The Effects of Climatic Parameters on Vegetation Cover and Forage Production of Four Grass Species in Semi-steppe Rangelands in Mazandaran Province, Iran
Mina Bayat Hossein Arzani Adel Jalili Saeedeh Nateghi -
Open Access Article
82 - Investigation of Climatic Parameters Affecting Annual Forage Production in BidAlam rangeland, Abadeh, Fars Province, Iran
Hossein Arzani Eshagh Omidvar Saeed Mohtashamnia Seyed akbar Javadi Mohammad Jafary -
Open Access Article
83 - Investigation of Relationship between Precipitation and Temperature with Range Production of Grasslands in North and North-east of Iran
Nafiseh Fakhar Izadi Kamal Naseri Mansoor Mesdaghi -
Open Access Article
84 - The Effect of Soil Moisture and Climatic Index of Evapotranspiration on Forage Production in Rangelands of Dehsir, Yazd province, Iran
Elham Fakhimi Hossein Arzani -
Open Access Article
85 - Influence of Pasture and Rainfed Agriculture Land Uses on Soil Loss in Dojag-Chay Subwatershed (Ardabil Province- NW Iran)
R. Talaei A. Jafari Ardakani F. Azimi R. Bayat M. Parehkar -
Open Access Article
86 - Rainfall Characteristics of the Liudaogou Catchment on the Northern Loess Plateau of China
Jinbai Huang Jing Li Hiroshi Yasuda Jiawei Wen -
Open Access Article
87 - Rainfall water quality assessment in atmospheric deposition of an urban area: A case study of Akure in Nigeria
Francis Abulude Mohammed Ndamitso Aishat Abdulkadir -
Open Access Article
88 - Precipitation-runoff Simulation with Neural Network(Case study: Nasa Bam Plain)
mehdi shahrokhi sardoo mojtaba jafari kermanipourShort-term runoff forecasting is of particular importance due to its direct relationship with how managers interact with life risks caused by floods. In this research, by using artificial neural networks, simulation of rainfall-runoff process has been done on a daily ba MoreShort-term runoff forecasting is of particular importance due to its direct relationship with how managers interact with life risks caused by floods. In this research, by using artificial neural networks, simulation of rainfall-runoff process has been done on a daily basis in the Nasa Bam watershed. In order to predict the future process of using the water resources of the mentioned plain, different combinations of rainfall and temperature data and discharge and discharge difference of two consecutive days were used. The number of hidden layer neurons in the neural network varied between 2 and 10 neurons. The statistical criteria of root mean square error RMSE, mean absolute value of error MAE and correlation coefficient R were used to evaluate and compare the performance of neural networks in runoff forecasting. The results showed that by having 2 inputs and feedforward neural network or 1 input and newrbe network, the best performance was achieved and the rainfall-runoff process was predicted with higher accuracy. Manuscript profile
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