Degradation severity assessment of groundwater resourses using the modified version of IMDPA and GIS in Shiraz plain, Fars province

Many agriculture and natural resources have turned into desert due to overuse and mismanagement of groundwater. The main cause of desertification and land degradation, in addition to natural factors, is improper human activities that lead to some consequences such as salinity and lowering the groundwater level. In this regard, the degradation severity assessment of groundwater resources was done in Shiraz plain to plan for encountering the degradation of groundwater resources. In this study, the modified IMDPA model was used to determine the severity of groundwater resources degradation. The final map of groundwater resources degradation was created by integrating the information layers of indices of water criterion. The results of this study indicated that about 55% of the main part of the plain is under moderate hazard class of water degradation and about 30% of it is under severe and very severe hazard classes of water degradation. The results of this study showed that the electrical conductivity index had the greatest impact on the degradation of groundwater resources in Shiraz plain. Moreover, it was found that the proposed model has a good performance in estimating the severity of groundwater resources degradation. Therefore, the model is recommended to be applied in similar areas to determine the severity of groundwater resources degradation.