Assessment and Mapping of Qualitatative and Quantitative Severity Degradation of Groundwater Resourses using the Modified IMDPA Desertification Model and GIS. A Case Study: Firuz-abad Plain of Fars province

Increasing of agricultural activity and industry cause Lowering of Water Table and problems like change in quality of groundwater, over-cost of pumping and subsidence of land. In order to optimal management of water resources, maintain and improve the quality and quantity of them, water data as their location, amount and distribution in a defined geographical area is required and necessary. According to this issue, in this study, hazard assessment of both qualitative and quantitative degradation of groundwater were done using the modified IMDPA model and geographical information system (GIS) in Firuz-abad plain of Fars province. In this research based on the indicators like Lowering of Water Table, Electrical conductivity (EC), Cl and SAR, severity classes of degradation were evaluated in the plain of study area. The required data of this study is related to precise data gathered by Fars Regional Water Company. The results of this study indicate that the Lowering of Water Table (quantitative status) in 97% of the plain is at very severe hazard class. The quality status of about 36% of the plain is at moderate hazard class. Overall, about 99 % of the plain are in a state of severe hazard class of ground water resources degradation.