Evaluation of the groundwater resources vulnerability index using nitrate concentration prediction approach

Abstract

This study evaluates the vulnerability of aquifers to the nitrate concentration variations. Prediction of nitrate concentration using MT3DMs modeling for a period of 10 years. The results showed that most of the wells have faced concentration increment, where it is exacerbated in the lower areas of agricultural and urban lands. The prediction of nitrate concentration zoning map obtained from the model was used to calibrate the DRASTIC vulnerability index in the aquifer. The AHP and Wilcoxon method was applied to calibrate the parameters of the DRASTIC index. The final results of the vulnerability index showed that the central aquifer parts located downstream of the agricultural lands and urban areas along the main drainage had the highest vulnerability degree. Correlation analysis showed that the correlation coefficient improved from 0.47 to 0.72, and the accuracy of the index was increased to identify the areas susceptible to development where have the least vulnerability.