| Abstrakt: |
In the semi-arid area, where climate variability is the main challenge, it is a critical issue to develop effective groundwater resource management. The study planned to investigate groundwater vulnerability by comparing the original and modified DRASTIC models. The DRASTIC approach included seven hydrogeological parameters: depth to water (D), net recharge (R), aquifer media (A), soil media (S), topography (T), the impact of vadose zone (I), and hydraulic conductivity (C). Lineament and LULC were included in the original DRASTIC parameters, and the impact of these parameters was determined using sensitivity analysis. The outcomes of the original and the modified DRASTIC index are between 73–204 and 87–263, respectively. These findings led to the classification of the research area into five categories of hazards: very low, low, moderate, high, and very high. The upper catchment is more vulnerable to groundwater contamination than the lower catchment. The sensitivity analysis shows that the depth and impact of the vadose zone are the main parameters that influence the vulnerability map. This study was validated using data on nitrate concentrations in groundwater from the study area. The study also discovered that nitrate contamination of the groundwater should be due to excessive agricultural application, grazing land, and other microbiological hazards in the northwestern portion. According to the validation outcome, the modified DRASTIC model provides better correlation results (R2 = 0.32) than the original (R2 = 0.25). These results serve as a guide for those who are in charge of making decisions regarding prevention of groundwater pollution in such a sensitive area. [ABSTRACT FROM AUTHOR] |
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