Groundwater vulnerability is normally associated with the potential for contamination, for example the DRASTIC approach, but the increasing importance of groundwater in human, agricultural, and industrial systems, implies that groundwater vulnerability is dependent on a range of other parameters and particularly parameters impacted by climate change. A robust method for evaluating groundwater vulnerability therefore requires the incorporation of multiple indices into one holistic evaluation. In this study, a model for groundwater vulnerability in South Africa was developed, calculating the combined weighted averages of nine spatial datasets; namely: (1) mean annual precipitation, (2) mean annual surface temperature, (3) tritium distribution in groundwater, (4) potential evaporation, (5) aquifer type and yield, (6) terrain slope, (7) electrical conductivity, (8) population density and (9) cultivated land use. The model was run through 36 different weighting scenarios and indicates that on average 22.4% of South Africa’s groundwater is predicted to have a very high vulnerability to depletion in quantity and deterioration in quality (12.2% very low; 35.4% low; 16.8% moderate and 13.1% high). A single weighting scenario (M-I/C-2/P-2) was chosen that showed good alignment to the previous assessments that predicted that 20.9% of groundwater resources in South Africa have very high vulnerability (1.5% very low; 35.7% low; 24.9% moderate and 17.0% high). The model was adjusted to reflect climate conditions 50 years into the future, resulting in a 3% increase in very high vulnerability areas and a 6% decrease in low vulnerability areas. The results suggest that large areas of South Africa have high groundwater vulnerability, especially in areas where groundwater supplements domestic supply and agriculture. The implementation of this method to evaluate groundwater vulnerability across diverse natural environments and political boundaries will supplement comprehensive groundwater vulnerability assessments and the development of effective groundwater management policy.

中文翻译：

---

结合数量和质量控制，确定整个南非的地下水易消耗和恶化的脆弱性

地下水脆弱性通常与潜在污染相关，例如DRASTIC方法，但是地下水在人，农业和工业系统中的重要性日益提高，这意味着地下水脆弱性取决于一系列其他参数，尤其是受气候影响的参数更改。因此，一种可靠的评估地下水脆弱性的方法需要将多个指标纳入一个整体评估中。在这项研究中，开发了南非地下水脆弱性模型，计算了9个空间数据集的组合加权平均值。即：（1）年平均降水量；（2）年平均表面温度；（3）地下水中的tri分布；（4）潜在蒸发；（5）含水层类型和产量；（6）地形坡度；（7）电导率，（8）人口密度和（9）耕地利用。该模型通过36种不同的加权方案进行了分析，结果表明，南非平均22.4％的地下水极易遭受数量枯竭和水质恶化的影响（极低的比例为12.2％；极低的比例为35.4％；中度的比例为16.8％；高13.1％）。选择了单一加权方案（MI / C-2 / P-2），该方案与先前的评估显示出很好的一致性，此前的评估预测南非20.9％的地下水资源具有极高的脆弱性（1.5％极低； 35.7％极低； 1.5％极低）。中度24.9％，高17.0％）。对该模型进行了调整，以反映未来50年的气候条件，从而使高脆弱性地区增加3％，低脆弱性地区减少6％。结果表明，南非大片地区具有很高的地下水脆弱性，特别是在地下水补充了国内供应和农业的地区。评估跨各种自然环境和政治边界的地下水脆弱性的方法的实施将补充全面的地下水脆弱性评估和有效的地下水管理政策的制定。