Spatial-Temporal Modeling of Groundwater Level Variations of Urban and Rural Areas in Kashan Aquifer Using GIS Techniques

The hydrograph and maps of groundwater level variations in Kashan aquifer demonstrate that during 2002-2011 the level of groundwater with depth moderate of 72.06 meter has decreased about 5.5 meter. When dealing with the quality of water resources for defferent uses, collecting samples from all parts of a study area is not economically possible, In this regard zoning methods are powerful tools in the providing the data based on spatial-temporal variations. This research aimed, modeling of level, depth and spatial-temporal variations Kashan aquifer groundwater table based on Cross validation technique of different methods of deterministic and geostatistic interpolation in GIS environment.
water level data of 67 observational wells in the region have been surveyed and compared to mapping of Kashan groundwater level during 2002-2011. Cross validation techniques have been employed and some criteria such as mean biased error (MBE), mean absolute error (MAE), root mean square error (RMSE) and R2 have been used to assess the performance of different methods and choosing the best one.
Findings: The results indicated that the local polynomials method with MBE = 0.444, MAE = 13.19, RMSE = 20.29 and R2 = 0.999 possessed the highest accuracy.
Discussion and Counclusion: As well as the results of this study showed that residential areas with high population due to the high aggravation of net recharge and forest areas increased groundwater level and activities in the industrial, agricultural and water extraction have caused a drastic reduction in groundwater level.