Assessment of groundwater contamination by using numerical methods

Groundwater vulnerability maps by numerical methods help to set priorities for identifying areas that are most affected by pollutants, enabling decision makers, departments and government agencies to save additional funds in the event of a groundwater monitoring and protection system for the entire study area.Numerical methods as SINTACS and Modified DRASTIC with GIS technologies are depended in this study. SINTACS Vulnerability Index (SVI) is based on seven parameters while Modified DRASTIC Index (MDI) is based on eight parameters but both methods are adopted weighted sum overlay of the parameters. Final results of SINTACS Vulnerability map depicts four classes from very low to high which varies from (77 to 144). About 82.81% of study area is classified under moderate vulnerability; the remaining 15.08% and 1.75% are under high and low vulnerability respectively. MD- DRASTIC vulnerability map ranges (85–179). This range of index values is divided into four classes including very low to high vulnerability classes. About (72.35%) of the study basin has moderate vulnerability. High vulnerability measured as a second effective class of the studied area with (20.5%). While low and very low areas comprise (6.45% and 0.6%) respectively. Comparative study of two vulnerability maps with water quality data represented by nitrate concentration showed that MD- DRASTIC method is more suitable to represent the real reality of pollution of the area. © 2021