Investigation of Groundwater quality under Climate Change and Drought Conditions in a mountainous catchment in Zagros

The Study of the spatial and temporal variations of groundwater quality plays an important role in the management of watershed fields in arid and semi-arid regions. Future climate parameters were predicted using HADCM3 and LARS-WG models under B1 and A2 scenarios and the data of minimum temperature, maximum temperature, precipitation and sunny hours of the base period (1992-1993) in the Silakhor -Borujerd agricultural plain. Dry and wet years were determined Using SPI drought index during the base period and future. Using the water quality data of 18 wells in the study area, the distribution of TDS, EC, PH, SAR parameters was studied using four main methods of geostatistic zoning (IDW, RBF, Kriging and Cokriging). The best model was selected using the root mean square root mean square error (RMSE). Finally, the effects of climate change and droughts on the geochemical parameters of water were investigated using factor analysis and analysis of variance. The results showed that for pH, TDS, SAR and EC parameters, conventional cokriging, simple coccygeal, simple cokriging and simple cokriging were more suitable. Among the studied parameters, TDS and EC had the highest correlation with mean temperature and SAR had no high correlation with the climate parameters. The pH parameter has a strong negative and significant negative temperature. The findings indicated that drought periods have no significant effect on water quality except PH. Climate change studies shows that by increasing the minimum and maximum temperatures, TDS and EC will increase in the future.