Groundwater Vulnerability Assessment in Saveh-Nobaran Basin, Iran Using GIS Based DRASTIC Model

The main goal of this paper is to assess groundwater pollution potentials of Saveh- Nobaran Basin, Iran, by producing the vulnerability maps of the aquifer. To achievethis aim the DRASTIC model has been applied to the study area with the help of GIS. DRASTIC method is a seven hydrogeological parametric model including: Depth toAquifer, Net Recharge, Aquifer Media, Soil Type, Topography, Impact of vadose Zone, and Hydraulic Conductivity. The required data were obtained from the relevant localorganizations. The groundwater intrinsic vulnerability map has been created byoverlaying the available data and the resulting map were then integrated with the land use map as a extra parameter in the DRASTIC model to assess more accurately thepotential risk of groundwater to contamination. Based on the research outcome, it was found that 10% and 8% of the study area is under very high and high vulnerability ofgroundwater pollution, respectively. Moreover, more than 20% of the basin is classified as having moderate vulnerability potential and finally, about 61% of thestudy area can be designated as an area of low vulnerability of groundwater contamination. Furthermore, single parameter and parameter removal sensitivity analysis were performed to evaluate relative importance of each DRASTIC modelparameters. Both analyses results show that the most sensitive parameter to influence the variation of the aquifers vulnerability index is impact of the vadose zone. Thepresent model can be used for assessment and management of both land use andgroundwater.

کلیدواژه ها:

DRASTIC ، GIS ، Groundwater Intrinsic vulnerability ، Land use ، Saveh- Nobaran basin