Department of Structures and Environmental Engineering, University of Agriculture Faisalabad, Faisalabad, 38000, Pakistan.
Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK, 74078, USA.
Environ Sci Pollut Res Int. 2022 Apr;29(18):27257-27278. doi: 10.1007/s11356-021-17882-9. Epub 2022 Jan 3.
The quality of groundwater in the study watershed has worsened because of industrial effluents and residential wastes from the urbanized cities; therefore, there is an important need to explore the aquifer vulnerability to pollution for sustainable groundwater management in the Irrigated Indus Basin (IIB). This study proposed a novel methodology to quantify groundwater vulnerability using two fully independent methodologies: the first by reintroducing an improved recharge factor (R) map and the second by incorporating three different weight and rating schemes into a traditional DRASTIC framework to improve the performance of the DRASTIC approach. In the current study, we composed a recharge map from Soil and Water Assessment Tool (SWAT) output (namely SWAT recharge map) with a drainage density map to retrieve an improved composite recharge map (SWAT-CRM). SWAT-CRM along with other thematic layers was combined using weightage overlay analysis to prepare the maps of groundwater vulnerability index (VI). The weight scale (w) and rating scale (r) were assigned based on a survey of available literature, and we then amended them using the analytical hierarchy process (AHP) and a probability frequency ratio (PFR) technique. Results depicted that the region under high groundwater vulnerability was found to be 5-22% using traditional recharge maps, while those are 9-23% using improved SWAT-CRM. The area under the curve (AUC) revealed that groundwater vulnerability zones predicted with SWAT-CRM outperformed the DRASTIC model applied with the traditional recharge map. Groundwater electrical conductivity (EC) was>2500 mS/cm in the high groundwater vulnerability zones, while it was <1000 mS/cm in the low groundwater vulnerability zones. The outcomes of this study can be used to improve the sustainability of the groundwater resources in IIB through proper land-use management practices.
研究流域的地下水水质因工业废水和城市居民废物而恶化；因此，需要探索含水层对污染的脆弱性，以实现灌溉印度河流域（IIB）的地下水可持续管理。本研究提出了一种使用两种完全独立的方法来量化地下水脆弱性的新方法：第一种方法是重新引入改进的补给因子（R）图，第二种方法是将三个不同的权重和评分方案纳入传统的 DRASTIC 框架中，以提高 DRASTIC 方法的性能。在当前的研究中，我们从土壤和水评估工具（SWAT）输出中组成了一张补给图（即 SWAT 补给图），并结合排水密度图，以获取改进的复合补给图（SWAT-CRM）。SWAT-CRM 与其他专题图层一起使用权重叠加分析进行组合，以制备地下水脆弱性指数（VI）图。权重尺度（w）和评分尺度（r）是根据现有文献调查分配的，然后使用层次分析法（AHP）和概率频率比（PFR）技术对其进行修正。结果表明，使用传统补给图，高地下水脆弱性区域的面积为 5-22%，而使用改进的 SWAT-CRM 的面积为 9-23%。曲线下面积（AUC）表明，使用 SWAT-CRM 预测的地下水脆弱性区域的表现优于应用传统补给图的 DRASTIC 模型。地下水电导率（EC）在高地下水脆弱性区域>2500 mS/cm，而在低地下水脆弱性区域<1000 mS/cm。本研究的结果可用于通过适当的土地利用管理实践来提高 IIB 地区地下水资源的可持续性。
