Geo-Statistics and its Application for Creating Iso-Maps in Hydro-Geology Electric Conductivity contours of Atrak sub basin, Iran

Taking discrete sampling from the water resource and measuring the parameters in quantity and quality and using the procedures of turning discrete points to integrated surface can lead the research process to surface variations consideration. There are different procedures for turning broken discrete points to integrated surface like procedure of Geostatistics which conclude Kriging procedure, Inverse Distance Weighting (IDW), Radial Basis Functions (RBF), Local Polynomial Interpolation, Global Polynomial Interpolation and Co-kriging. This research is going to explain any applications of Geostatistics for creating iso-maps such as underground water table contours, Iso-quality (for example EC and pH) contours, and place changes of too many other hydro-geological parameters. In this way, statistic signs such as Mean Absolute Error (MAE), Mean Absolute Relative Error (MARE), Root Mean Square Error (RMSE), MBE and Coefficient of Correlation, could be employed to select the best Geo-Statistic model in a GIS framework. Eventually, the power in IDW method has been optimized and also best Geo-Statistic method has been introduced for predicting the Electric Conductivity (EC) of underground water in Atrak plain. Finally any conclusions have been extracted. Table No. 1: Comparison of Statistical Indices for Best Estimator Selection G.S Method r RMSE MBE MAE Kriging 0.81 2200 485 1740 RBF 0.79 2263 427 1662 GPI 0.63 2981 347 2031 LPI 0.64 2942 349 2002 Power Optimized IDW 0.459 4816 -183 2845 The use of MAE shows the amount of absolute error, With regard to table No.1 kriging and RBF models have the best estimation which has the least absolute estimation error. As one of results figure No. 2 shows the Iso-Electric Conductivity Map which has been created by Kriging Method in a GIS Framework.; Figure No. 1: Power optimization in IDW method and the minimum of RMSE ; Figure No.2: Iso-Electric Conductivity Map which has been created by Kriging Method in a GIS Framework