• OpenAccess
    • List of Articles Drought

      • Open Access Article

        1 - Modeling the correlation between drought, number of rainy days and evapotranspiration in Fars province
        maryam khosravian alireza entezari Mohammad baaghide rahman zandi
        Drought is one of the recurring phenomena in all parts of the world with high-rainfall and low-rainfall climates and it is consider as a natural disaster. Iran is also one of the countries which involved in this phenomenon in different places. Its characteristics, such More
        Drought is one of the recurring phenomena in all parts of the world with high-rainfall and low-rainfall climates and it is consider as a natural disaster. Iran is also one of the countries which involved in this phenomenon in different places. Its characteristics, such as the severity, duration, and extent of the drought, are vary from place to place and its damages is depending on the country's planning. In this regard, the necessity of knowing the correct weather conditions and climatic characteristics of different regions have become clear to planners through environmental, economic, agricultural and industrial potentials and their optimal use, as well as predicting the occurrence of natural disasters such as floods and droughts. In this study, for evaluating and comparing drought and wetness events, the precipitation data for the period (1987-2017), as well as the evaporation and transpiration data and the number of rainy days during a statistical period of 10 years (2008-2017) were obtained from 9 stations in Fars province. The standardized precipitation index (SPI) was used, and the Arc GIS software, the drought zoning, evaporation and transpiration maps, and the number of rainy days in the province were plotted. In the studied years, Fars province has faced a near-normal state for 24 years in and drought for 5 years and wetness for one year. The drought situation was studied and analyzed in Shiraz city in the continuation. According to the obtained results, the drought in Shiraz city is more severe than the other parts of the province and it will continue in the future. The SPI index has the highest correlation with the parameters of the number of rainy days with a rate of (0.46) and evaporation and transpiration with a rate of (0.26) in 2012 and 2008. Manuscript profile
      • Open Access Article

        2 - Evaluation of trend of rainfall and temperature changes and their effects on meteorological drought in Kermanshah province
        Maryam Teymouri Yeganeh Liela Teymouri Yeganeh
        Climate change is one of the natural features of the atmospheric cycle, which results in anomalies or fluctuations in the process of meteorological parameters such as rainfall and temperature. Also, drought is one of the weather and climate disasters, including catastro More
        Climate change is one of the natural features of the atmospheric cycle, which results in anomalies or fluctuations in the process of meteorological parameters such as rainfall and temperature. Also, drought is one of the weather and climate disasters, including catastrophic events. It alternates with floods and causes significant damage each year. Lack of rainfall has different effects on groundwater, soil moisture and river flow. For this reason, the study of changes in precipitation and temperature has always been the focus of researchers in various sciences, including natural resources and the environment. In this study, using the data of Kermanshah Meteorological Organization related to 30 years of rainfall, average minimum temperature and average maximum temperature in three stations of Kermanshah, Islamabad West and Sarpol-e Zahab to assess the severity of drought each year by DIC software Using standard precipitation index (SPI) and examining the trend of temperature changes using two non-parametric Mann-Kendall tests, Sensitimator and also linear regression. In order to study the drought trend during the 30-year period, statistical software was used and the results showed that during the 30-year period, all three stations are in near normal condition. Also, the results of temperature changes using the mentioned tests indicate the increasing trend of temperature and this trend is significant at the level of 99% using two non-parametric Mann-Kendall tests. Manuscript profile
      • Open Access Article

        3 - Comparison of the effects of pollution caused by Saravan wastes on Kacha River during drought and wet year
        مینا جعفری هانیه میربلوکی fatemeh ghanbari
        Waste landfills change over time due to exposure to physical and biological factors, these changes include the production of leachate and its penetration into the subsoil, groundwater pollution, production and emission of gases from waste decomposition, and finally the More
        Waste landfills change over time due to exposure to physical and biological factors, these changes include the production of leachate and its penetration into the subsoil, groundwater pollution, production and emission of gases from waste decomposition, and finally the settlement in the site. The leachate produced flows in different layers of waste and carries toxic and polluted substances to surface or groundwater. Kacha River, which carries the contamination load from Saravan landfill, flows into Siahrud River; Siahroud passes through this lands on its way, flows to the north and after joining Goharroud, enters the eastern part of Anzali Wetland. In this study, sampling stations were located in Saravan landfill and Kacha River and sampling was done in winter and summer and COD, BOD, TDS, pH, EC, ammonia, phosphate and nitrate parameters were measured. Comparison of the results of leachate analysis of Saravan landfill and Kacha River in summer and winter showed that all parameters, including BOD and COD parameters, which are indicators of contamination load in the Kacha River, increased in the drought season (summer) compared to the wet season (winter) Which indicates the amount of more pollution from Saravan landfill to Kacha River and from there to Gohar River and finally Anzali wetland. Manuscript profile