شاخص spI

Open Access Article

1 - Predict The drought situation in the province of lorestan during the Years of 2013-2030 Using Down-scaling output of 4 general circulation model
Fatemeh Dargahian Behrooz Parvaneh Hengameh Shiravand

  One of the consequences of climate change, is drought. Identification, monitoring, and evaluation of the occurrence of droughts is very important.Studying the drought phenomenon in the Lorestan province of Iran is important, both in terms of agricultural producti More

  One of the consequences of climate change, is drought. Identification, monitoring, and evaluation of the occurrence of droughts is very important.Studying the drought phenomenon in the Lorestan province of Iran is important, both in terms of agricultural production and horticulture . In this study, the effects of droughts due to climate change were studied. We analyzed the standardized precipitation index (SPI) to accomplish this. We analyzed the circulation model (HADCM - INCM-IPCM-NCCCSM). We examined scenarios (B1, A2, A1B) with a statistical model. The statistical model we used was LARS-WG version 5, the fine-scale LARS-WG. Nine synoptic stations have been approved to evaluate the climate parameters. The climate parameters evaluated were: Minimum temperature, Maximum temperature, Rainfall and sunshine hours. This study covered the period 2011-2030 using this model. The final forecast according to the weight of each scenario and Hormel, The Synoptic prediction Nasraqlymy for all sites in this study has been done. The results show that the average of all the stations in the first and second volume will increase rainfall forecast .Next, we analyze the rainfall data, to evaluate the status of drought in the province. We reviewed the SPI drought index on the scale annually. The results show that over the next two decades, drought at most stations is reduced. We also found that wet conditions increased in the overall state of synoptic stations in through most of the coming years to 2030. Manuscript profile

Open Access Article

2 - Drought Forecasting Using Wavelet - Support Vector Machine and Standardized Precipitation Index (Case Study: Urmia Lake-Iran)
Mehdi Komasi Soroush Sharghi

10.22034/jest.2020.9578

Background 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 More

Background 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

3 - Evaluation of the role of drought in frequency of dust in Khorasan Razavi province
mehdi boroghani Hamidreza moradi Mohamadali Zangane Asadi Sima Pourhashemi

10.22034/jest.2019.10464

Background 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 More

Background 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

4 - The Investigation of the relationship between groundwater level variation and drought index (Case study: Sharifabad Watershed in Qom Province)
Elham Forootan Fatemeh Golpayegani

10.22034/jest.2018.29165.3774

Background and objective: The climate change phenomenon affects water storage in aquifers through changes in rainfall volume. In this study, the aim is to estimate the average groundwater level using the most appropriate geostatistical method and then investigate the re More

Background and objective: The climate change phenomenon affects water storage in aquifers through changes in rainfall volume. In this study, the aim is to estimate the average groundwater level using the most appropriate geostatistical method and then investigate the relationship between groundwater index and one of the drought indices on monthly and annual scale in order to specify the importance of rainfall in groundwater recharge. Method: The watershed of this study was Sharifabad watershed located in Qom province with an aquifer area of 27035/2 hectares. There are 16 observation wells in this area. In this study, during the period of 1384-1384, the water level of observation wells in the area was investigated using variogram models. The average water level was determined using the best model per year, then the SWI index at the watershed was calculated. The SPI index, one of the drought indicators, was also used to investigate precipitation variation and then, using Pearson coefficient, the correlation of these indices was investigated on monthly and annual scale. Findings: The results showed that among the variogram models that were used to interpolate the monthly water level data, Kriging model is the most appropriate. Also, Pearson correlation coefficient between SWI and SPI indicators is not significant on monthly basis at confidence level of 99% in both observations of Mozafarabad and Alborz. Moreover; this correlation coefficient on the annual scale is not meaningful either. Discussion and Conclusion: In this study, the insignificance relationship between SPI and groundwater index in the study area indicates that precipitation has a small proportion in groundwater recharge in the water balance of these areas on monthly and annual scale. Therefore, it can be concluded that the most part of rainfall is out of reach due to excessive evapotranspiration and is not able to recharge the aquifer  in the region. Manuscript profile

Open Access Article

5 - Investigating the Effects of Climate Change on Meteorological Drought Characteristics of Hablehrood Basin Using the HADCM3 General Circulation Model and the SPI and DI Index
Afshin Ashrafzade jaber salehpoor arezoo sharifi

Climate change is one of the most important challenges that affect different parts of human life. One of the most important consequences of climate change is the impact on water resources and the occurrence of droughts. In this research, the effects of climate change on More

Climate change is one of the most important challenges that affect different parts of human life. One of the most important consequences of climate change is the impact on water resources and the occurrence of droughts. In this research, the effects of climate change on the drought condition of Hablehrood watershed during the next three decades were evaluated using Decile Drought Index and Standardized Precipitation Index (SPI). Initially, the monthly data of the output of the HADCM3 General Circulation Model )GCM(, under the A2 scenario were Downscaled in the LARS-WG5 statistical model and the ability of this model to simulate the past climate (1995-1995 period) Firoozkooh synoptic stations basin Hablehrood watershed was approved. Then, climatic parameters of the minimum temperature, maximum temperature, precipitation and sunshine for the period 2040-2011 were simulated for the station studied. The results obtained from the station showed that the average annual maximum temperature would increase to 0.47 degrees Celsius, and the minimum temperatures would be 0.56 degrees Celsius. Annual precipitation fluctuations are not significantly different with rainfall during the base period, so that precipitation 0.06mm will be changed in the future period. Then, using rainfall data, the drought condition of the basin was studied using the two droughts Index mentioned in the annual scale. The results showed that these two Index are well-matched Manuscript profile

Open Access Article

6 - تحلیل و بررسی تاثیر نوسانات اقلیمی بر کوچ عشایر فارس (مطالعه موردی طایفه عمله)
حسن لشکری محمد ابراهیم عفیفی زهرا پربار

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Open Access Article

7 - Environmental sustainability assessment with emphasis on drought and water resources using multi-criteria artificial neural network technology (case study of Babak city)
محمد ابراهیم عفیفی ahmad mangeli meydook ali vakhsoori

In this study, first, by studying the research, criteria and sub-criteria were identified that are effective in terms of environmental sustainability. After the Delphi stages, the criteria of environmental resources and services, environmental health and energy were sel More

In this study, first, by studying the research, criteria and sub-criteria were identified that are effective in terms of environmental sustainability. After the Delphi stages, the criteria of environmental resources and services, environmental health and energy were selected as the most important criteria for assessing environmental sustainability in Babak, then using the neural network model to analyze and evaluate the environmental sustainability of Babak. In this study, drought in Babak city was analyzed with a SPI index of drought during a statistical period of 32 years 1361-1392. This index is specifically for time series six; Twelve and forty-eight months were calculated. The city of Babak has been facing drought during the statistical period of thirty-two years, especially the last seven years, and on an annual scale of six months, most of its droughts are mild to moderate droughts. But in the long-term Myas 48 months, 75% of the droughts were severe and very severe, which shows a high relationship with the quantitative and qualitative decline of groundwater in this area. Manuscript profile

Open Access Article

8 - The Examination of Evaluating Modei of Drought and Wet Year at Mahshahr and Andimeshk Stations
Farideh Azimi Gholam Ali Farhadvand Manizheh Zohourian

Drought is a climatic phenomenon caused by a period of unusual dry conditions which is stable enough to cause instability in the hydrological situation of an area. The average annual rainfall of the country is about 250 millimeters that is less than the average rainfall More

Drought is a climatic phenomenon caused by a period of unusual dry conditions which is stable enough to cause instability in the hydrological situation of an area. The average annual rainfall of the country is about 250 millimeters that is less than the average rainfall of Asia and about one-third of world’s average rainfall. According to Khuzestan station’s rainfalls and based on the Belter’s method, Khuzestan is located on the dry to mid-humid climatic region. Due to the importance of drought and its effect on the economic, social, biological, and even cultural issues, it is necessary to exactly assess this phenomenon. One of the significant and fundamental elements in drought studies in each area is the detection of some indexes for the intensity and lasting of drought period. In this paper, drought phenomenon in two stations of Mahshahr and Andimeshk in a period of twenty years (1370-1389), was analyzed by using the rainfall standardized index (SPI), percent ofnormality (PN), Nietzsche method, normal Z and decileindex. The results proved that in all the indexes, the years with normal rainfalls are more stable and lasting than the dry and humid years. So, based on the SPI index, Andimeshkstation has 13 years of almost normal rainfall. During this twenty years period, a terrible drought had happened on the year 87. Mahshahrstation has 15 years of almost normal rainfalls that is 2 years more than Andimeshk. Very strong humid year only happened on the year 76 and on the year 87,and the average drought was recorded for this station. According to PN index, on the year 87 on both Andimeshk and Mahshahr stations a terrible drought happened. According to Nietzsche method, 13 normal years in Andimeshk and 15 normal years for Mahshahr had happened. According to normal Z index, 2 years on Andimeshk(1381-1387) station and 1 year on Mahshahr (1387) was attributed as a rainfall with drought. According to deciles index, the driest years in both Andimeshk and Mahshahr stations are 87 and 78 which are in the first decile. Manuscript profile

Open Access Article

9 - تحلیل و بررسی تاثیر نوسانات اقلیمی بر کوچ عشایر فارس (مطالعه موردی طایفه عمله)
حسن لشکری محمد ابراهیم عفیفی زهرا پربار

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Open Access Article

10 - Temporal and Spatial Vvariability Analysis of Drought Hazard in Khuzestan Province Using Standardized Precipitation Index (SPI)
fatemeh zohrabzadeh hossein eslami

Drought is a natural hazard with climatic nature. It caused by the precipitation anomalies and irregularities. This paper examines the phenomenon of drought and its spatial and temporal changes in Khuzestan province. In order to determine the severity of the drought, it More

Drought is a natural hazard with climatic nature. It caused by the precipitation anomalies and irregularities. This paper examines the phenomenon of drought and its spatial and temporal changes in Khuzestan province. In order to determine the severity of the drought, it used Standardized Precipitation Index (SPI) for spatial analysis benefits and temporal communication creation between occurrences of drought. In this study, 48 rain gauges and synoptic stations data from Khuzestan province have been used in years (1982-2014). Zoning maps of Standardized precipitation index (SPI) was drawn using ordinary kriging interpolation method during the study period and the driest and wettest years were identified. The 1999 and 2008 was severe drought years and extreme wet occurred in 1992. According to the results, 1999, 2007 and 2008 were years with the largest percentage of the area of drought and years 1991, 1992, 1997 and 2001 with the highest percentage of wet. Manuscript profile

Open Access Article

11 - Using several drought indices in Water resources management in drought condition (Case Study of Shahid Abbaspour Dam Station)
ABBAS SAFAEI Masoud Choramin kimiya korkani

Drought is one of the natural disasters that cause great damage to human life and natural ecosystems and is different from other natural disasters. The main differences in the gradual impact of drought over a relatively long period are the impossibility of determining t More

Drought is one of the natural disasters that cause great damage to human life and natural ecosystems and is different from other natural disasters. The main differences in the gradual impact of drought over a relatively long period are the impossibility of determining the exact time of onset and end and the geographical extent of its impact. On the other hand, the lack of an accurate and acceptable global definition of drought has added to the complexity and confusion of this phenomenon. And the severity of droughts was determined and described based on drought indices ZSI, PNPI, SPI. These indicators are consistent with each other so that based on the above indicators. the results show that in Shahid Abbaspour Dam in the wet years (2007-2008) the most severe drought occurred in the statistical period. SPI index of drought periods Shows more, so it is a more sensitive index than ZSI and PNPI and has a higher sensitivity and more complete classification in the study of dry periods. Manuscript profile

Open Access Article

12 - بررسی دوره های خشکسالی و تاثیر آن بر منابع آب پایین دست کرخه
علیرضا شکیبا فریده عظیمی فاطمه بوعذار

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