Drought is an insidious hazard of nature. It is often referred to as a ''creeping phenomenon,'' and its impacts vary from region to region. Studies show that the best approach to managing drought is to apply a comprehensive drought management plan. This system necessitates collecting reliable information to make decisions to decrease the risk and damages caused by drought. Therefore, the first step of the comprehensive drought management is accomplished by preparation of the drought vulnerability map. The main object of this study was to provide for agriculture drought vulnerability mapping for Taft town located in Yazd Province, Iran. To do so, with regard to factors affecting on agricultural drought, maps were prepared for each factor and analytic hierarchy process technique was applied to determine the importance of each map as an input parameter on agricultural drought vulnerability. All input maps and the output of this research, an agricultural drought vulnerability map, were provided and analyzed by geographic information systems.Then, to evaluate and validate how accurately the vulnerability map shows the degree of proneness to agricultural droughts, some ground control points (GCP) were taken into consideration. Results indicated that there is a good agreement between agricultural drought vulnerability map and GCPs in many cases. Also, results showed that mountainous regions of the study area are more vulnerable to agriculture droughts compared with plains. These results can be helpful for decision makers to mitigate agricultural drought impacts over the region, although implementing a drought risk management plan requires a detailed study covering different aspects of drought.

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Geostatistical methods are one of the advanced techniques used for interpolation of groundwater quality data. The results obtained from geostatistics will be useful for decision makers to adopt suitable remedial measures to protect the quality of groundwater sources. Data used in this study were collected from 78 wells in Varamin plain aquifer located in southeast of Tehran, Iran, in 2013. Ordinary kriging method was used in this study to evaluate groundwater quality parameters. According to what has been mentioned in this paper, seven main quality parameters (i.e. total dissolved solids (TDS), sodium adsorption ratio (SAR), electrical conductivity (EC), sodium (Na + ), total hardness (TH), chloride (Cl − ) and sulfate (SO 4 2− )), have been analyzed and interpreted by statistical and geostatistical methods. After data normalization by Nscore method in WinGslib software, variography as a geostatistical tool to define spatial regression was compiled and experimental variograms were plotted by GS + software. Then, the best theoretical model was fitted to each variogram based on the minimum RSS. Cross validation method was used to determine the accuracy of the estimated data. Eventually, estimation maps of groundwater quality were prepared in WinGslib software and estimation variance map and estimation error map were presented to evaluate the quality of estimation in each estimated point. Results showed that kriging method is more accurate than the traditional interpolation methods.