The assessment vulnerability of Qazvin-plain aquifer, sensitivity analysis removing parameters by using GIS

These days, boom in agricultural section, use of pesticide lavishly, disposal of Industrial and urban wastes result in boosting the probability of aquifer pollution. So, it needs to identify the vulnerable regions for preventing of groundwater pollution and land use management. Thus, we use four methods (AVI، GOD، DRASTIC و SINTACS) for evaluating of ground water contamination in Qazvin- plain. Based on the comparison between indexes and classifications show the majority of vulnerability classification in this region is low to moderate. DRASTIC and SINTACS indexes are the most sensitivities in the central of plain. AVI index is low sensitive and GOD index is classified in moderate. By comparison the following indexes, the vulnerability of SINTACS index region calculated more conservative than other indexes, but AVI index is the lowest vulnerability. Among the above indicators with respect to the groundwater sensitivity in the area, SINTACS index is the better estimation than other indexes. The amount of effective parameters for determining vulnerability in DRASTIC and SINTACS by using the remove of parameters been evaluated, finally the analytical results show that the net nutrition parameters and the type of soil were the most impact on vulnerability of this region.