Evaluation Groundwater quality parameters using GIS and Geostatistics (Case Study: Mehran Plain and Dehloran Ilam)

In this study, Mehran and Dehloran groundwater chemical variables were studied using geostatistical methods (kriging and co-kriging). Sodium, chloride, sulfate, TDS and TH of 29 water wells, were chemical analyzed from 2001 to 2014. The method of co-kriging and kriging interpolation was done using Arc GIS 10 software. Lower RMSE and strong spatial structure were used to select the appropriate model to fit the experimental variogram. The results of RMSE and MAE showed that the co-kriging is better than the kriging method. This is due to a low RMSE and MAE in co-kriging method indicates the high precision and lower error, and the results show that water quality data in this area are the strong correlation and their spatial structure follow spherical and exponential models. Finally, zoning map of the study area were obtained using co-kriging method, fuzzy logic and Sholer classification. According to the final map, 32, 18 and 50% of the area are suitable for drinking, relatively good and inappropriate, respectively. The results showed that water quality in the study area is not desirable for drinking. Areas with high concentrations of the warning threshold are located next to each other and in inappropriate zoning map class with overlay zoning map and the map of Hot spot analysis.