Applying fundamental geostatistical approaches to determine potential zones of groundwater recharge of Tehran-Karaj Plain Aquifer

Groundwater, especially in arid and semi-arid is one of the main sources of drinking water. Contrary to public perception in these areas the water quality is more important than quantify. Therefore, monitoring of water quality and identification of pollution sources is one of the main concerns of researchers in this area. In this study, in order to identify sources of groundwater contamination, areas are likely aquifer recharge sources of Tehran-Karaj plain detected. So, after extraction of groundwater level data different interpolation and geostatistics methods are used to create surface images. The Gstat software and Geostatistical Analyst were used for this study then performance and ability of each one to produce surface images are evaluated. According to the results, the Geostatistical Analyst software has better flexibility to do the special analysis. Based on the training and test data interpolation methods were very similar, but the surface images regarding groundwater direction flow and histogram look very different. According to the results, universal kriging showed better performance. Accordingly, surface images of different time created by an appropriate method to simulate groundwater flow direction and eventually areas were identified which are more likely ground water recharge source of Tehran-Karaj aquifer.