Heidelberg Center for the Environment (HCE), Heidelberg University, Heidelberg, Germany.
Department of Geography, South Asia Institute (SAI), Heidelberg University, Heidelberg, Germany.
Environ Monit Assess. 2018 May 8;190(6):334. doi: 10.1007/s10661-018-6664-9.
This case study examines the geological imprint and land use practices on water quality in the arid Huasco Valley against the backdrop of ongoing water conflicts surrounding competing demands for agriculture and mining. The study is based on a detailed analysis of spatial and temporal variations of monthly surface and bi-monthly groundwater quality samples measured during the Chilean summer of 2015/16. Additional information on source regions and river-groundwater interactions were collected using stable water isotopes. Regarding the geological impact on water quality, high concentrations of Ca, SO and HCO indicate a strong influence of magmatic rocks, which constitute this high mountain basin, on the hydrochemistry. Piper and Gibbs-diagrams revealed that all samples show a homogenous distribution dominated by rock-water interactions. Measured NO concentrations in surface water are generally low. However, groundwater aquifers exhibit higher concentrations. Mn is the only heavy metal with elevated concentrations in surface water, which are possibly related to mining activities. The results illustrate that both surface and groundwater can be classified as suitable for irrigation. In addition, groundwater has been found to be suitable as drinking water. High similarities in isotopic signatures indicate a strong connection between surface and groundwater. Isotopic analyses suggest a strong influence of evaporation. This combined approach of hydrogeochemical and isotopic analysis proved to be a helpful tool in characterizing the catchment and can serve as a basis for future sustainable water management.
本案例研究考察了在干旱的瓦斯科山谷中，地质印记和土地利用实践对水质的影响，背景是围绕农业和矿业竞争需求的持续水冲突。该研究基于对 2015/16 年智利夏季每月地表水和每两个月地下水质量样本的时空变化的详细分析。使用稳定同位素收集了有关源区和河地下水相互作用的额外信息。关于地质对水质的影响，高浓度的 Ca、SO 和 HCO 表明岩浆岩的强烈影响，这些岩浆岩构成了这个高山盆地，对水化学有很大影响。Piper 和 Gibbs 图表明，所有样本都显示出由岩石-水相互作用主导的均匀分布。地表水的测量 NO 浓度通常较低。然而，地下水含水层的浓度较高。Mn 是唯一一种在地表水中浓度升高的重金属，可能与采矿活动有关。结果表明，地表水和地下水都可归类为适合灌溉的水。此外，地下水也被发现适合作为饮用水。同位素特征的高度相似性表明地表水和地下水之间有很强的联系。同位素分析表明蒸发有很大的影响。这种水文地球化学和同位素分析的综合方法被证明是一种描述集水区的有用工具，并可以作为未来可持续水资源管理的基础。
