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Open Access Article
1 - Satellite indicators in drought monitoring in Iran
seyed mahdi PAZHUHANought is a natural manifestation influenced by climatic conditions and is considered one of Iran's significant morphoclimatic phenomena. The appearance of this phenomenon is linked to variations in climatic elements such as temperature and precipitation. Drought, as a d Moreought is a natural manifestation influenced by climatic conditions and is considered one of Iran's significant morphoclimatic phenomena. The appearance of this phenomenon is linked to variations in climatic elements such as temperature and precipitation. Drought, as a destructive climatic event, can have adverse effects on the ecology of any region if not properly managed, with its economic losses being a crucial feedback. Effective monitoring of drought is essential for its management. In this research, the most practical indicators for satellite monitoring of drought have been defined and implemented using meteorological satellite images. This method proves to be more economical and time-efficient compared to traditional methods, including field monitoring. The analysis of satellite indicators revealed that, firstly, the electromagnetic spectrum ranges of 670 nm (red band) and 765 nm (infrared band) are commonly utilized in all plant indicators. Secondly, the output map generated from these indicators demonstrates their high efficacy in revealing vegetation changes and, consequently, monitoring drought. Manuscript profile -
Open Access Article
2 - Assess the social challenges arising from the drought crisis on sustainable rural development: Case Study: Miandeh parts Shabiikuh district, city of Fasa
جمیله توکلی نیا محمدرضا پاک نهاد حسین رئیسی پرویز آقاییThe research method is descriptive - analytical and data collection and survey documents. Sampling has been done in two levels, firstly in terms of region which is the unit for analyzing rural areas and it includes Miandeh, Nasir-Abad, Rahim-Abad, and Sade; secondly the MoreThe research method is descriptive - analytical and data collection and survey documents. Sampling has been done in two levels, firstly in terms of region which is the unit for analyzing rural areas and it includes Miandeh, Nasir-Abad, Rahim-Abad, and Sade; secondly there are the sample villages which are the unit for analyzing the residents in the rural areas. It is based on the last consensus in 1390 which totaled 2101 household. In the present study, for defining the suitable sample, Kukran formula has been applied, and the right sample for this population equals 325 household. In analyzing the data, social challenges arising from the drought crisis includes five factors, namely general societal impacts, security, quality of life, education, health and well-being. The whole set of social challenges is there to explain 57.190 of total variance of the social challenges of rural villages in Miandeh .schools are discussed. The results of the present study sheds light on the necessity of paying attention to social aspect and its vulnerability when drought occurs because, not paying attention to this aspect at the time of drought leads to critical challenges in development. Manuscript profile -
Open Access Article
3 - Drought Forecasting Using Wavelet - Support Vector Machine and Standardized Precipitation Index (Case Study: Urmia Lake-Iran)
Mehdi Komasi Soroush SharghiBackground and Objectives: Drought is regarded as a serious threat for people and environment. As a result, finding some indices to forecast the drought is an important issue that needs to be addressed urgently. The appropriate and flexible index for drought classificat MoreBackground and Objectives: Drought is regarded as a serious threat for people and environment. As a result, finding some indices to forecast the drought is an important issue that needs to be addressed urgently. The appropriate and flexible index for drought classification is the Standardized Precipitation Index (SPI). Artificial intelligence models were commonly used to forecast SPI time series. These models are based on auto regressive property. So, they are not able to monitor the seasonal and long-term patterns in time series. In this study, the Wavelet-Support Vector Machine (WSVM) approach was used for the drought forecasting through employing SPI. Method: In this way, the SPI time series of Urmia Lake watershed was decomposed to multiple frequent time series by wavelet transform; then, these time series were imposed as input data to the Support Vector Machine (SVM) model to forecast the drought. Findings: The results showed that, the maximum value of R2 and minimum value of RMSE indexes for SVM model are 0.865 and 0.237 and for WSVM model are 0.954 and 0.056 respectively in verification step. Discussion and Conclusion: So, the propounded hybrid model has superior ability in forecasting SPI time series comparing with the single SVM model and also it can accurately assess the extreme data in SPI time series by considering the seasonality effects. Finally, it was concluded that, the proposed hybrid model is relatively more appropriate than classical autoregressive models such as ANN. Manuscript profile -
Open Access Article
4 - Determining the Monthly Wet and Dry Regimes Using Angot Precipitation Index in Ardabil Station
Roghayeh Asiabi-hir Raoof Mostafazadeh Saied NabaviBackground and Objective: Drought is the main causes of socioeconomic and environmental issues and the spatial and temporal variability of precipitation has a great influence on water resources availability. The Angot Precipitation Index (ratio between the average value MoreBackground and Objective: Drought is the main causes of socioeconomic and environmental issues and the spatial and temporal variability of precipitation has a great influence on water resources availability. The Angot Precipitation Index (ratio between the average values of multiannual of precipitation over wet and dry periods) is an indicator to determine the precipitation variations. The API highlights the climate significance of every month to detect dry or rainy regime.Material and Methodology: This study aims to assess and calculation of API in analysis of dry-wet periods of monthly precipitation in Ardabil station. The API values were calculated based on average daily values of precipitation in a year. Based on API values, dry and wet months were identified and the relationship between API and monthly precipitation characteristics according to Pearson correlation coefficient.Findings: According to the results, the value of API was 2.33 for the May month as a wet month and the November and April months are determined as normal precipitation regime (1.65 and 1.57 values, respectively) and other months have been classified into dry months as the API is less than the unity. Also, the API had a negative correlation with precipitation coefficient of variation (R2=0.408), and a positive correlation is exist between average monthly precipitation amounts and the API (R2=0.998).Discussion and Conclusion: The maximum API index value was observed in November and May months. The results indicated that the amount of Angot index was inversely correlated with coefficient of variations; while a direct relationship is exist with average monthly precipitations. Application of Angot index allows the determination of monthly precipitation regime on the basis of the vale ranges of the calculated index. Comparing the results of other drought indices in determining wet and dry months in climatic zones of Iran needs further investigations. Manuscript profile -
Open Access Article
5 - Evaluation of the role of drought in frequency of dust in Khorasan Razavi province
mehdi boroghani Hamidreza moradi Mohamadali Zangane Asadi Sima PourhashemiBackground and Objective: In arid and semi-arid regions dust phenomenon occurs frequently. These phenomenon seriously affects the human health, soil erosion, desertification and transport. Drought is one of the natural phenomena that decrease precipitation, reduce veget MoreBackground and Objective: In arid and semi-arid regions dust phenomenon occurs frequently. These phenomenon seriously affects the human health, soil erosion, desertification and transport. Drought is one of the natural phenomena that decrease precipitation, reduce vegetation and increase dust in case study. The purpose of this study was to examine the relationship between the number of dust events and climatic drought. Method: In this study, SPI index was used to estimate drought. Rainfall data for the years 1980-2010 and data of the dust for the years 2004-2010 were analyzed. The zoning dust and drought in the same period (2010-2004) was performed using the Kriging method in ArcGIS software. Findings: The results of zoning the occurrence of dust and drought suggest that the greatest number of dust events (226 dust events) and severe drought happened in the province in 2008. Also, in 2005, the lowest number of dust events (85 dust events) and wet conditions prevailed in the province. Discussion and Conclusion: The results indicate the direct relationship between dust event and drought, and dust event increased or decreased during the years that drought intensity increased or decreased. Manuscript profile -
Open Access Article
6 - Zoning of Drought by Integrating Satellite Imagery and Ground–Based Climate Data (Case study: Malayer Plain)
Ahmad Asadi Meyabadi Davoud Akhzari Hamid NouriBackground and Objective: One of the most important consequences of drought is reducing the amount of vegetation. Reducing vegetation and environmental conditions lead various problems such as soil erosion, increased runoff levels and flood risk. Accordingly, evaluation MoreBackground and Objective: One of the most important consequences of drought is reducing the amount of vegetation. Reducing vegetation and environmental conditions lead various problems such as soil erosion, increased runoff levels and flood risk. Accordingly, evaluation of the effects of drought on vegetation has a great importance. The purpose of this study is to use the Drought Effect Index (IDI), remotely sensed data and terrestrial data in the study area.Method: The IDI index indicates the long-term effects of climate conditions in the study area on the vegetation cover in area. In this study, the IDI index combines data of the meteorological stations of Malayer Plain to prepare rainfall and temperature maps (information from 5 synoptic stations inside and outside of study area with a 19-years scale) and a series of Landsat TM satellites and ETM + were calculated for the NDVI vegetation mapping (including 6 images in May and 2000, 2002, 2007, 2009, 2013 and 2015). The zonation map was prepared based on this information. This investigation has been done in May 2019.Findings: The results showed that there is a meaningful correlation between aggregate data (IDI) and SPI index, indicates the efficiency of combined data. Results of Pearson correlation showed that there is a significant correlation between the mean SPI and IDI of 0.963 at a significant level of P<0.01.Discussion and Conclusions: So far, land and satellite data have been widely used for the study of droughts, but the index derived from the integration of these data has received little attention from researchers, so the aim and innovation of this research is to make it possible to use drought impact index (IDI). Combine terrestrial and satellite data in the study area. Manuscript profile -
Open Access Article
7 - Modeling of villagers' behavior in the face of drought risk in Lake Urmia (Case study: villages in Bonab County)
Alireza Soleimani Majid Parishan Ali Majnouni- ToutakhaneBackground and Objective: Perception of risk leads to the regulation of practical behaviors to deal with it. The purpose of this study is to analyze the experimental behaviors of villagers in Bonab city to understand the risk of drought in Lake Urmia. For this purpose, MoreBackground and Objective: Perception of risk leads to the regulation of practical behaviors to deal with it. The purpose of this study is to analyze the experimental behaviors of villagers in Bonab city to understand the risk of drought in Lake Urmia. For this purpose, a combination of individual and social approaches was used. Material and Methodology: The present study is descriptive-analytical. The statistical population of the study is residents over 15 years old in 29 villages of Bonab city, which is equal to 23653 people. Using Cochran's method and simple random method, 380 people were selected as the sample size. The tool used in this research is a questionnaire. Data were analyzed using SPSS software and multivariate regression tests, and path analysis. Findings: The results of path analysis on the dependent variable showed that drought-tolerant crop, knowledge and skills, income, age, length of stay, participation in training programs, and modernization of irrigation canals have a direct effect on practical behaviors to reduce drought risk. Also, the results of path analysis on the dependent variable of intention to perform risk reduction behaviors in the future, showed that the variables of cultivation of drought-tolerant crops, self-efficacy, age, level of education, trust, previous experience, and responsibility have a positive effect and optimistic bias variables, income, and age. The risk perception variable had a negative effect. Indirect effects through the two variables of believes and income also affect the variable of intention to reduce the risk of drought. Discussion and Conclusion: According to the research results, the perception of drought risk by the villagers, this understanding has not yet changed the behavior of the rural community in practice. Manuscript profile -
Open Access Article
8 - Evaluation of drought in South Khorasan province (Iran) using normal precipitation index (PNPI) and standardized method index (Z)
Mohammad Hossein Jahangir Mohammad SaraniradBackground and Objective: Drought is among the natural disasters which happens in a long period of time and intermittently makes problems for human societies and consequently the economy through negative effects on water resources and agriculture compared to other natur MoreBackground and Objective: Drought is among the natural disasters which happens in a long period of time and intermittently makes problems for human societies and consequently the economy through negative effects on water resources and agriculture compared to other natural phenomena. Thus, the basic step in drought studies is to select appropriate indicators for each area based on severity, duration and magnitude of drought in the study area. The aim of this study is to select appropriate indicators to classify and determine the degree of severity of the drought and wet and to identify the drought prone regions in South Khorasan province for planning and better management of drought. The values of drought severity were calculated by the desired index for each station using Matlab software. Then, based on the tables for each index, the drought and wet intensities were determined. Method: In this study, the situation of drought in South Khorasan province was evaluated using the drought index, weather percent of normal precipitation (PNPI) and standard methods of index (Z). Since most stations do not cover the long-term (30 years) statistics of precipitation data, the available stations with the precipitation data for period of 24 years (2014- 1990) were used. Findings: PNPI index results showed that among the studied stations, Khor Birjand stations with 5 months, Boshrooyeh, Ghain and Ferdous stations with 4 months and Birjand and Nehbandan stations with 3 months has the longest wet period. Drought is in the range of moderate drought to moderate humidity in most stations. The highest Z (wet 1/84) belongs to Nehbandan station in March and most of the stations experience moderate drought in June, July, August, September and October. Discussion and Conclusion: The two methods show that the drought is in the range of moderate drought to moderate humidity in most of the stations. According to the results of hypothesis evaluation, the drought has been very severe and has led to occurrence of minimum annual precipitation. In this study, PNPI index was found to be a more appropriate index for the region. Manuscript profile -
Open Access Article
9 - Investigation of meteorological, hydrological and agricultural drought using drought indices (Case study: Gharehsou watershed)
Mahshid Karimi Kaka ShahediDrought as a natural hazard has always affected some parts of the country. Nowadays, it is possible to study drought using remote sensing techniques through its effects on the plants and achieve more accurate and efficient results for drought modelling. This study aims MoreDrought as a natural hazard has always affected some parts of the country. Nowadays, it is possible to study drought using remote sensing techniques through its effects on the plants and achieve more accurate and efficient results for drought modelling. This study aims to investigate the relationship between meteorological, hydrological and agricultural drought using drought indices and remote sensing method in Gharehsou watershed. For this purpose, MODIS images (satellite Terra, product MODO9Q1) and rainfall and discharge data of five meteorological and hydrometric stations for 2000 to 2015 time period were used. The results of the comparison of meteorological, hydrological and agricultural drought represent conformity of the three types of drought in the years 2000, 2001, 2004, 2005, 2007, 2009, 2010, 2011, 2012, 2013, 2014 and 2015. Although the SPI and NDVI values were positive in the years 2002, 2003 and 2008, SDI index showed the occurrence of hydrological drought (negative values). In the year 2006 despite the rainfall increase, but this year has been facing the agricultural and hydrological drought. So the results simultaneity of drought there does not exist in all the years. The results of Pearson correlation showed there is a high correlation between mean NDVI and SPI and SDI indices equal to 0.706 and 0.788 respectively at the significance level of 0.01. Generally, the results of SDI and SPI indices largely confirm the results of the NDVI index. Manuscript profile -
Open Access Article
10 - Drought prediction and modeling by hybrid wavelet method and neural network algorithms
Jahanbakhsh Mohammadi Alireza Vafaeinezhad Saeed Behzadi Hossein Aghamohammadi Amirhooman HemmasiBackground and Objective A drought crisis is a dry period of climate that can occur anywhere globally and with any climate. Although this crisis starts slowly, it can have a serious impact on health, agricultural products, the economy, energy, and the environment for a MoreBackground and Objective A drought crisis is a dry period of climate that can occur anywhere globally and with any climate. Although this crisis starts slowly, it can have a serious impact on health, agricultural products, the economy, energy, and the environment for a long time to come. Drought severely threatens human livelihood and health and increases the risk of various diseases. Therefore, modeling and predicting drought is one of the most important and serious issues in the scientific community. In the past, mathematical and statistical models such as simple regression, Auto-regression (AR), moving average (MA), and ARIMA were used to model the drought. In recent years, machine learning methods and computational intelligence to model and predict drought have been of great interest to scientists. Computational intelligence algorithms that have been previously considered by scientists to model drought include multilayer perceptron neural network, RBF neural network, support vector machine, fuzzy, and ANFIS methods. In this research, the purpose of modeling and predicting drought is by using three neural network algorithms, including multilayer perceptron, RBF neural network, and generalized regression neural. The drought index used in this research is the standardized precipitation index (SPI). In this research, the wavelet technique in combination with artificial neural network algorithms for modeling and predicting drought in 10 synoptic stations in Iran (Abadan, Babolsar, Bandar Abbas, Kerman, Mashhad, Rasht, Saqez, Tehran, Tabriz, and Zahedan) have been used in different climates and with suitable spatial distribution throughout Iran.Materials and Methods This study, initially using monthly precipitation data between 1961 and 2017, SPI drought index in time scales of 3, 6, 12, 18, 24, and 48 months through programming in soft environment MATLAB software implemented. The results of this step were validated using the available scientific software MDM and Drinc. Then, prediction models were designed using the Markov chain. In this study, a total of six computational intelligence models, including three single models of multilayer perceptron neural network (MLP), radial basis function neural network (RBF), and generalized regression neural network (GRNN), and three hybrids wavelet models with these three models (WMLP-WRBF-WGRNN) have been used to model and predict the SPI index in 10 stations of this research. In implementing all these six models, the MATLAB software programming environment has been used. In this study, four types of discrete wavelets were used, including Daubechies, Symlets, Coiflets, and Biorthogonal. Due to the better performance of the Dobbies wavelet, this type of wavelet was used as a final option in the research. In the Daubechies wavelet used between levels 1 to 45, level 3 showed the best performance among different SPI time scales; therefore, the Daubechies level 3 wavelet was used in all hybrid models of this study. After training all six algorithms used, the evaluation criteria of coefficient of determination (R2) and root mean square error (RMSE) was used to measure the difference between actual and estimated values.Results and Discussion The results of this study showed that computational intelligence methods have high accuracy in modeling and predicting the SPI drought index. In the first stage, the results showed that the individual MLP, RBF, and GRNN models, if properly trained, have close results in modeling and predicting the SPI drought index. In the next step, it was observed that the wavelet technique would improve the modeling results. In using the wavelet technique in combination with three single models MLP, RBF, and GRNN, the choice of wavelet type is also more effective in modeling, so in this research, the first of the four types of discrete wavelets Daubechies, Symlet, Qoiflet, and Biorthogonal in combination with Three single models of this research were used and the results of these four types of wavelets showed the relative superiority of the Daubechies wavelet over the other three wavelets. In using the Daubechies wavelet, since this wavelet has 45 times and the choice of order was also effective in modeling, it was observed by testing the wavelet 45 times that the 3rd wavelet, in general, has higher accuracy in all time scales of SPI index, 3, 6, 12, 18, 24 and 48 months and also in all three algorithms MLP, RBF, and GRNN. Therefore, in this research, the third-order Daubechies wavelet was used in all three algorithms of this research, as well as in all time scales. The results showed that combining the wavelet technique with all three models MLP, RBF, and GRNN will improve the results. The research graphs showed that for the quarterly time scale, the values obtained from the single model prediction in MLP and RBF modeling have a somewhat one-month phase difference compared to the hybrid model, while in the GRNN model, this prediction difference is negligible. The modeling results for both single and hybrid modeling modes indicate that there is no phase difference between the single and hybrid modeling methods in time scales of 6, 12, 18, 24, and 48. For the 12- and 24-month time scales, the single GRNN model had more fluctuations and errors in SPI monthly modeling and forecasting, while the hybrid model in these two-time scales had much better behavior in monthly modeling and forecasting. Distribution diagrams of data related to observational SPI of Abadan station showed that the modeling results for single and hybrid modes in 3 and 6-month time scales are less accurate than other time scales and fit line separation, and its uncertainty is higher than others. However, in all neural network models and in all time scales, the hybrid method has shown more accuracy. The numerical results of the study indicate that in all SPIs and stations under study, the differential values of R2 are positive, which indicates higher values of R2 in the hybrid model than in single neural network modeling, which indicates an improvement in hybrid modeling compared to individual models. Also, the differential values of RMSE are negative in all studied models and stations, which indicates that the amount of RMSE in predicting hybrid models is lower than individual neural network models. In the research graphs, it can be seen that the amount of differences in RMSE and R2 indicates a greater difference in time scales 3 and 6 than the time scales 12, 18, 24, and 48, which somehow goes back to the nature of the data of these time scales. The most significant improvement in R2 and RMSE is from the 3-month low to the 48-month high, respectively.Conclusion From the findings of this study, it can be concluded that artificial neural network algorithms are efficient methods for modeling and predicting the SPI drought index. The use of wavelets in all three models of artificial neural networks will also improve the results. It can also be concluded that for better modeling of the SPI drought index, it is necessary to select the optimal wavelet type and order. From the results of this study, it can be concluded that the wavelet technique has a greater impact on the lower time scales, i.e., 3 and 6 months, than the higher scales, i.e., 24 and 48 months. Manuscript profile -
Open Access Article
11 - شبیه سازی و آشکارسازی نوسانات جریان آبراهه ای با شدت خشک سالی با بهره گیری از مدلWEAP
ارمین بنی بیات حسین قربانی زاده خرازی حسین اسلامی صائب خوش نواز بهروز دهان زادهدر این مطالعه نیاز به انتقال آب در سطوح مختلف توسعه کشاورزی در قالب طرح انتقال آب از سولگان (ونک) به خان‎میرزا مورد بررسی قرار گرفت. در تمامی سناریوهای این گروه اجرای طرح انتقال آب از سولگان به دشت خان‎میرزا (طرح سد ونک) در نظر گرفته شده است. سناریوهای اجرا شده Moreدر این مطالعه نیاز به انتقال آب در سطوح مختلف توسعه کشاورزی در قالب طرح انتقال آب از سولگان (ونک) به خان‎میرزا مورد بررسی قرار گرفت. در تمامی سناریوهای این گروه اجرای طرح انتقال آب از سولگان به دشت خان‎میرزا (طرح سد ونک) در نظر گرفته شده است. سناریوهای اجرا شده در مدل WEAP شامل اجرای طرح تغذیه مصنوعی و همچنین افزایش سطح زیرکشت و افزایش راندمان آبیاری برای به تعادل رسیدن بیلان دشت خان‎میرزا می­باشد. نتایج سناریو اول نشان داد که برای به تعادل رسیدن بیلان آب زیرزمینی دشت باید سالیانه حداقل 45 میلیون مترمکعب آب از سولگان به دشت خان‎میرزا انتقال داده شود. نتایج سناریوی دوم نشان داد که در صورت انتقال کامل آب سولگان به خان‎میرزا می­توان میزان سطح زیرکشت اراضی را تا 21000 هکتار توسعه داد. نتایج سناریوی سوم نشان داد که در صورت انتقال کامل آب سولگان به خان‎میرزا و اجرای کامل طرح آبیاری تحت فشار می­توان علاوه بر تعادل بخشی آبخوان خان‎میرزا، میزان سطح زیرکشت اراضی را تا 26000 هکتار توسعه داد. همچنین سناریوی چهارم نشان داد که در صورت انتقال کامل آب سولگان به خان‎میرزا (یعنی انتقال رقم 200 میلیون مترمکعب در سال) و اجرای کامل طرح آبیاری تحت فشار و اجرای طرح تغذیه مصنوعی سالانه 10 میلیون مترمکعب، می­توان میزان سطح زیر کشت اراضی را تا 30000 هکتار توسعه داد. Manuscript profile -
Open Access Article
12 - Drought Evaluation and Climatic Impact Assessment in Guilan Province
Pejvak Rastgou Bahman Ramezani parviz rezayiIran is affected by subtropical high pressure in the arid belt of the world and its annual rainfall is less than one third of the world average rainfall. The aim of this study was to assess the vulnerability of Guilan province to drought with fuzzy GAMA, SUM and CVI mod MoreIran is affected by subtropical high pressure in the arid belt of the world and its annual rainfall is less than one third of the world average rainfall. The aim of this study was to assess the vulnerability of Guilan province to drought with fuzzy GAMA, SUM and CVI models and to identify appropriate measures to reduce potential damage. The research method was spatial and applied in terms of purpose. First, , the components of resources (R), meteorological (W), access (A), capacity (C), use and economic productivity (U), maintaining environmental integrity (E), Geographical features (G) were determined. The variables were matched with fuzzy membership functions. In the SUM model, the highest vulnerability was in the west, center and large areas of the east of the province, Rudsar city with an area of 78.23%. In the GAMA overlap model, large parts of the west of Talesh city and Rasht city with an area of 31.92% were observed in a very high vulnerability class. In the study of CVI components, the CVI index of the whole province was 44.5%. The CVI index had the highest rank in the resource component (R) at 56.12% and the lowest rank in the 36.94% component. In the CVI model, the highest vulnerability is in the whole city of Talesh with an area of 15.57%. High vulnerability rate of 26.84% was observed in Rasht, Soomehsara, Rudsar and Shaft counties and Astara and Rezvanshahr counties with an area of 20.88% were observed in very low vulnerability class. Manuscript profile -
Open Access Article
13 - Urban development and the characteristics of short and medium-term hydrological drought in the Samian watershed of Ardabil province
Saeed Rasinezami hadi izadifard Raoof Mostafazadeh Hassan KhavarianHydrological drought is affected by many factors and is quantified using SDI index. The purpose of this research is to evaluate the urban development with satellite images between 1992 and 2016 and to evaluate its effect on the characteristics of hydrological drought ev MoreHydrological drought is affected by many factors and is quantified using SDI index. The purpose of this research is to evaluate the urban development with satellite images between 1992 and 2016 and to evaluate its effect on the characteristics of hydrological drought events in the Samian area of Ardabil province. Land use change assessment shows that the agricultural and residential areas have been increased. Examination of the one-month SDI index in all stations shows an increase in droughts in different periods. The highest number of dry months is related to the last period (2017-2008) of Samian station for 80 months. The highest increase in the number of dry months is related to Gilande station, which has increased from 1 month in the first period to 66 months in the last period. The study of the quarterly SDI index in all stations except Atashghah station shows the increase of drought in different periods. The highest increase in the number of dry quarters is related to Gilande station, which has increased from zero in the first period to 36 in the last period. Despite the increase in rainfall during the period and the presence of wet climatic months, as well as the relative increase in temperature in the region and due to increased agricultural use and residential areas that have increased the harvest of surface water, the number of dry months in the region has increased. Manuscript profile -
Open Access Article
14 - Comparison of CVI and AHP methods in drought assessment and climate vulnerability assessment of Guilan province
Pejvak Rastgoo Bahman Ramezani Parviz RezaeiDrought is one of the most costly natural disasters in Iran and the need for a study to determine vulnerability and identify the factors affecting it in different parts of the country.The aim of this study was to compare CVI and AHP methods in assessing drought and meas MoreDrought is one of the most costly natural disasters in Iran and the need for a study to determine vulnerability and identify the factors affecting it in different parts of the country.The aim of this study was to compare CVI and AHP methods in assessing drought and measuring climatic vulnerability in Guilan province in order to identify its dimensions.The research method is spatial and applied in terms of purpose. In the AHP model, the importance of the resource component (R) with a weight of 0.293 is the highest and the weight of the component of geographical features (G) with a weight of 0.045 is the lowest. In the study of variables in the AHP model, the variable of total rainfall with a weight of 0.750 was the most effective variable and the variety and quality of agricultural products with a weight of 0.088 was the least effective variable according to experts. In the study of CVI components, the CVI index of the whole province was 44.5%. The CVI index had the highest rating in the resource component (R) at 56.12% and the lowest rating in the 36.94% component. The zoning of the AHP model showed that the middle part of the province, including Rasht, Saravan, Kasma, Anzali, has the highest area with an area of 42.11%. In the CVI model,the highest vulnerability is in the whole city of Talesh with an area of 15.57%.Astara and Rezvanshahr cities with an area of 20.88% were observed in a very low vulnerability class. Manuscript profile -
Open Access Article
15 - Analysis of the effect of drought phenomenon on dust events in different regions of Ghazvin province
Samira Zandifar mohammad khosroshahi Zohre Ebrahimi-KhusfiThis study was conducted to investigate the effect of drought on dust events in different cities of Qazvin province. Rainfall and temperature data were used to calculate the standardized precipitation-evapotranspiration index (SPEI) and three-hourly dust events data wer MoreThis study was conducted to investigate the effect of drought on dust events in different cities of Qazvin province. Rainfall and temperature data were used to calculate the standardized precipitation-evapotranspiration index (SPEI) and three-hourly dust events data were used to calculate the number of dusty days in the study stations. Based on the Spearman correlation coefficient, the impact of dust events on the drought phenomenon was investigated by considering different time delays. The maximum correlation between SPEI and the number of dusty days in Ghazvin city without considering the time delay of -0.38 and at the level of 99%, was significant, indicating the simultaneous impact of dust events from the drought phenomenon in the center of the province. The results also showed that the response time of dust events to meteorological drought with a delay of one year in Moallem Kalayeh city is significant at 90% confidence level (r = -0.52). Meanwhile, in other cities of Ghazvin province, no significant relationship was observed between the two phenomena of dust occurrence and meteorological drought. Manuscript profile -
Open Access Article
16 - Investigating the Relationship between Northern Hemisphere Transplant Patterns and Drought in Northwestern Iran
Yosof Toloei Amir Gandomkar Mohsen Bagheri BadaghabadiDrought is a climatic phenomenon that is likely to occur in any region and leads to social, economic and environmental damage. Due to the importance of remote linking patterns and their impact on climate, therefore, the present study aimed to investigate the relationshi MoreDrought is a climatic phenomenon that is likely to occur in any region and leads to social, economic and environmental damage. Due to the importance of remote linking patterns and their impact on climate, therefore, the present study aimed to investigate the relationship between remote linking patterns and drought in northwestern Iran. In this regard, the precipitation statistics of 17 synoptic stations located in the provinces of East Azerbaijan, West Azerbaijan, Ardabil and Zanjan during the statistical period 1988 to 2018 and the statistics of 16 connection patterns from the Northern Hemisphere during the same period were used. First, using the drought index (SPI) of the study area on an annual scale, with a delay of one month and a delay of two months. Then, the relationship between drought and remote grafting patterns was investigated using Pearson correlation and linear regression methods. The results show that on a monthly scale, the PNA pattern showed a correlation with the studied stations more than other patterns in the one-month delay time of the TNA pattern and in the two-month delay time of the NAO pattern. Spatially, Maragheh and Jolfa stations have shown more correlation with remote connection patterns than other stations. Examination of seasonal correlation coefficients also showed that in winter HCNA and SNA patterns; NAM, NPI and PN patterns in spring; In summer, the SNAO pattern and in autumn, the POL / PEP pattern were more correlated with the drought of the studied stations than other patterns. Manuscript profile -
Open Access Article
17 - Analysis and Comparison of SPI and GRI Indices in Assessing Meteorological Drought and Groundwater, Case Study: Mehran Plain, Ilam Province
Ali Abbasinia jafar morshedi Mnizheh Zohoriyan Jebrael GhorbaniyanDroughts are one of the most devastating weather events, causing significant damage to both natural resources and human life. The purpose of this study is to analyze and compare meteorological drought and groundwater of Mehran plain using standardized precipitation inde MoreDroughts are one of the most devastating weather events, causing significant damage to both natural resources and human life. The purpose of this study is to analyze and compare meteorological drought and groundwater of Mehran plain using standardized precipitation index (SPI) and groundwater index (GRI). In order to study the meteorological drought, the monthly rainfall information of Mehran synoptic station was used and in order to study the dryness of the groundwater of Mehran plain, the changes of groundwater level of Mehran plain were analyzed based on water level data of 23 observation wells. Also, SPI index was used for meteorological drought monitoring and GRI index was used for hydrological drought monitoring of Mehran plain. The statistical period required for drought analysis of a 25-year statistical period from the water year of 75-74 to 97-96 was selected. After determining the moisture periods of the indices, monthly groundwater zoning maps were prepared. To prepare these maps, the kriging model was selected from among different models. Finally, by applying the optimal half-change model in kriging and entering groundwater data as a point layer, raster maps were prepared using Arc GIS software. The results of the study of SPI index show that during the statistical periods in question, 4 severe droughts occurred, the most severe of which was 90-91, with a value of SPI index of -1.73. Also, the results obtained from the GRI index in the region show that an 11-year drought period of groundwater occurred, ie it started from the water year 88-87 and continued until the water year 98-97, the most severe of which was 90-91 with the amount of The index is -1.11. Manuscript profile -
Open Access Article
18 - Assessing the relationship between the occurrence of drought and changes in the water area of Anzali Wetland using Landsat satellite images
Kivan Asadi Parviz Rezaei Bahman Ramezani GorabiClimate change is one of the greatest dangers facing human beings now and in future generations. The phenomenon of climate change has caused many changes in spatial patterns of rainfall and has led to an increase in marginal phenomena such as drought. It is also predict MoreClimate change is one of the greatest dangers facing human beings now and in future generations. The phenomenon of climate change has caused many changes in spatial patterns of rainfall and has led to an increase in marginal phenomena such as drought. It is also predicted that climate change will affect the frequency, severity and duration of drought. Drought occurs in all climates, even in humid and semi-humid climates, so wetlands, which are one of the most important habitats on Earth, are no exception. In this study, drought events in Anzali wetland and its relationship with changes in wetland area during the statistical period 1975-2016 have been investigated. Two SPI and RDI indices have been used to study drought. Landsat satellite imagery was used to determine the blue zone. The study of drought indices in Anzali wetland shows that the values obtained by RDI index estimate drought with less intensity than the values obtained by SPI index. The results also showed that the water area of Anzali wetland has a decreasing trend during the years under study, which is completely consistent with the increasing trend of drought in terms of frequency and severity. Manuscript profile -
Open Access Article
19 - پایش شاخصهای خشکسالی در شهر زاهدان در بازههای زمانی مختلف
محمدرضا پودینه محمدرضا پودینه محمدحیدری نیا محمدحیدری نیا سید روح ا...موسوی سید روح ا...موسوی حسین دوستی مقدم* حسین دوستی مقدم*هدف پژوهش حاضر بررسی شاخصهایخشکسالیدر بازههای زمانی مختلف در شهر زاهدان است. جهت دستیابی به اهداف پژوهش از دادههای بارش ماهانهایستگاه سینوپتیک زاهدان در دوره زمانی (2012– 1995) استفاده شد. نتایج این پژوهشنشان میدهد که خشکسالی شدید و بسیار شدید بهوسیله شاخص Moreهدف پژوهش حاضر بررسی شاخصهایخشکسالیدر بازههای زمانی مختلف در شهر زاهدان است. جهت دستیابی به اهداف پژوهش از دادههای بارش ماهانهایستگاه سینوپتیک زاهدان در دوره زمانی (2012– 1995) استفاده شد. نتایج این پژوهشنشان میدهد که خشکسالی شدید و بسیار شدید بهوسیله شاخص ZSIدر هیچیک از دورههای زمانی تشخیص داده نشد. این شاخص برای مطالعات مقایسهای چندان مفید تشخیص داده نشد. همچنین برای پی بردن به رابطه بین شاخصها ضریب همبستگی تمام شاخصها در سه بازه زمانی سه، شش و دوازده ماهه بهدست آمد که نتایج نشان داد که هر چه بازه زمانی افزایش مییابد هماهنگی سه شاخص جهت پایش خشکسالی در زاهدان افزایش مییابد. هماهنگی در رفتار این سه شاخص را میتوان در بررسی نوسانات مشاهده کرد که بهطور کلی شاخص SPI نسبت به شاخصهایZSIو CZIخشکسالی را بهتر نشان میدهد. همچنین شاخص ZSI بیشترین درصد خشکسالی کلی را نسبت به شاخص SPI و CZI در همه بازههای زمانی داشته است که علت آن سهم زیاد این شاخص در وضعیت خشکسالی ضعیف و متوسط است Manuscript profile -
Open Access Article
20 - Investigation of PN, SIAP, RAI indices in Khuzestan Province with Emphasis on Ahwaz, Abadan, Dezful and Omidieh stations
mussa molaei Peyman GravandIn this paper, the meteorological droughts of four selected stations in Khuzestan based on the annual precipitation index (SIAP), Normal precipitation (PNPI) and precipitation anomalies (RAI) in a 32-year statistical period (1983-2003) were investigated. Drought index c MoreIn this paper, the meteorological droughts of four selected stations in Khuzestan based on the annual precipitation index (SIAP), Normal precipitation (PNPI) and precipitation anomalies (RAI) in a 32-year statistical period (1983-2003) were investigated. Drought index coefficients and frequency and severity of drought were determined based on each indicator. Each of the indicators was calculated at the stations. The results showed that frequency and sequence (continuity period) of drought were different in different degrees according to the index of (SIAP) in Dezful in the statistical period. In the PNPI survey, Abandon droughts were more frequent than other stations. The most severe drought occurred in Ahwaz based on this indicator. According to the RAI index, the frequency of drought in Dezful is greater And due to the severity of drought in Omidieh, the highest severity of drought occurred. Finally, among the three indexes studied, the highest drought persistence is related to the( PNPI) index Manuscript profile -
Open Access Article
21 - The evidences for the prominence of the Goddess Anahita during the reign of Artaxerxes II(358-405 B.C)
Atousa AhmadiThis article strives to explain the factors leading to the prominence of the Goddess Anahita in that particular epoque based on the evidence found in the inscriptions in the Achaemanid era, and Aban Yasht in Avesta. Also reference is made to the writings of Greek histor MoreThis article strives to explain the factors leading to the prominence of the Goddess Anahita in that particular epoque based on the evidence found in the inscriptions in the Achaemanid era, and Aban Yasht in Avesta. Also reference is made to the writings of Greek historians to justify the significance of the Goddess Anahita, at the time of the drought, happening probably during the reign of Artaxerxes II. The climate of Iran’s plateau is also taken into consideration. Manuscript profile
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