New Approach in Assessing Groundwater Quality Using Geo-statistical methods(Hotspot Analysis): Case Study of Kerman Plain

This paper investigates the effectiveness of Kriging and Inverse Desistance Weighting (IDW) methods and Hotspot analysis in evaluation of groundwater quality in Kerman Plain, Iran. In order to conduct this study the information regarding the concentration level of electrical conductivity (EC), total dissolved salts (TDS) and sodium adsorption ratio (SAR) of 60 exploiting wells in the study area were obtained. The positional accuracy and correctness of this information were confirmed. Then, interpolation maps were produced for EC, TDS and SAR parameters using the raw data and the output of hotspot analysis (Z-Score) with the application of IDW and Kriging methods. This result demonstrates preferability of Kriging in regard to IDW using the output of Hotspot analysis (Z-Score), as the experts don’t interfere with the range and number and produced maps are based on geostatistical analysis. Furthermore, the resulted maps indicated sharp boundaries of very high and very low concentration of each parameter and the calculated area for EC (1411, 1063 km2), TDS (1874, 1470 km2) and SAR (321, 396 km2) are very close to reality. Accordingly, applying the output of hotspot analysis in combination with other interpolation methods can assist researchers in determining the extent of very high and very low concentration of a parameter and in calculating the area of the affected region.