Liu Fei, Song Xianfang, Zhen Pinna, Wang Lishu, Wang Shou
College of Water Conservancy and Hydropower, Hebei University of Engineering , Handan , People's Republic of China.
Department of Hydrology and Atmospheric Sciences, University of Arizona , Tucson , AZ , USA.
Isotopes Environ Health Stud. 2019 Oct;55(5):438-458. doi: 10.1080/10256016.2019.1654472. Epub 2019 Aug 22.
Changes in groundwater evolutionary processes due to aquifer overexploitation show a world-wide increase and have been of growing concern in recent years. The study aimed to improve the knowledge of groundwater evolutionary processes by means of stable water isotopes and hydrochemistry in a representative lake basin, Ordos energy base. Groundwater, precipitation, and lake water collected during four campaigns were analysed by stable isotopes and chemical compositions. Results showed that temperature effect predominated the isotope fractionation in precipitation, while evaporation and inadequate groundwater recharge were the key factors explaining high salinity and isotopic enrichment in lake water. Additionally, the Kuisheng Lake was a preferential area of groundwater recharge, while the Subei Lake received less sources from underlying aquifer due to the combined effects of low permeable zone and upstream groundwater captured by the production wells. The homogeneous isotope signatures of groundwater may be ascribed to the closely vertical hydraulic connectivity between the unconfined and the confined aquifers. Isotopically enriched groundwater pumping from well field probably promoted isotopic depletion in groundwater depression cone. These findings not only provide the conceptual framework for the inland basin, but also have important implications for sustainable groundwater management in other groundwater discharge basins with arid climate.
由于含水层过度开采导致的地下水演化过程变化在全球范围内呈上升趋势，近年来日益受到关注。本研究旨在通过鄂尔多斯能源基地这一典型湖盆中的稳定水同位素和水化学方法，增进对地下水演化过程的认识。对在四个采样时段采集的地下水、降水和湖水进行了稳定同位素和化学成分分析。结果表明，温度效应在降水中的同位素分馏中占主导地位，而蒸发和地下水补给不足是导致湖水高盐度和同位素富集的关键因素。此外，奎生湖是地下水补给的优先区域，而由于低渗透带和生产井对上游地下水的截留的综合作用，苏北湖从下伏含水层获得的水源较少。地下水同位素特征的均匀性可能归因于潜水含水层和承压含水层之间紧密的垂向水力连通性。从井场抽取的同位素富集的地下水可能促进了地下水降落漏斗中的同位素贫化。这些发现不仅为内陆盆地提供了概念框架，也对其他干旱气候下的地下水排泄盆地的可持续地下水管理具有重要意义。
