Yi Bing, Liu Jing-Tao, Lü Xiao-Li, He Wei, Zhu Liang, Zhang Yu-Xi, Yang Ming-Nan
Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang, 050061, China.
College of Water Resources and Environment, China University of Geosciences, Beijing 100083, China.
Huan Jing Ke Xue. 2023 Feb 8;44(2):752-760. doi: 10.13227/j.hjkx.202204232.
Global warming and regional extreme climates will lead to unbalanced rainfall, melting glaciers, and permafrost degradation in alpine and arid mountain plains, thereby changing the regional hydrological cycle. The relationship between surface water and groundwater conversion is one of the important scientific issues of hydrological cycle climate response in alpine arid areas. Taking the Datong River Basin at the southern foot of the Qilian Mountains as the study area, based on 119 sets of basic hydrochemical parameters and deuterium-oxygen isotope data, using multivariate statistical analysis and isotopic techniques, the hydrochemical characteristics of surface water and groundwater in the basin and their mutual transformation process were studied. The results showed that the surface water was HCO-Mg·Ca type, which was mainly controlled by rock weathering, whereas the groundwater was HCO-Mg·Ca type and Cl·SO-Na type, which was controlled by rock weathering and evaporation concentration. There was a small amount of calcium and magnesium feldspar dissolved in the upstream groundwater, and the chemical components of the midstream groundwater were mainly the weathering and dissolution of carbonate rocks. The contribution rates of weathering filtration, anthropogenic activities, native sedimentary environment, alternating adsorption of cations, and other factors to the chemical components of surface water and groundwater in the study area were 39.1%, 15.0%, 12.6%, 13.8%, and 19.5%, respectively. The deuterium and oxygen isotope contents of Datong River water showed a trend of enrichment to depletion along the groundwater flow direction. The D and O isotope test results showed that the deuterium and oxygen isotope content in the Datong River along the groundwater flow showed a trend of enrichment to depletion. The upper and middle reaches of the Datong River were mainly recharged by atmospheric precipitation, whereas the lower reaches were affected by geological structure and influenced by hydrogeological conditions, which was mainly due to diving and spring water overflow to supply river water, as the discharge area of groundwater.
全球变暖和区域极端气候将导致降雨不均衡、冰川融化以及高山和干旱山区平原的多年冻土退化，从而改变区域水文循环。地表水与地下水转换关系是高寒干旱地区水文循环气候响应的重要科学问题之一。以祁连山南麓大通河流域为研究区，基于119组基本水化学参数和氘氧同位素数据，运用多元统计分析和同位素技术，研究了流域地表水和地下水的水化学特征及其相互转化过程。结果表明，地表水为HCO-Mg·Ca型，主要受岩石风化控制，而地下水为HCO-Mg·Ca型和Cl·SO-Na型，受岩石风化和蒸发浓缩控制。上游地下水中溶解有少量钙长石和镁长石，中游地下水化学成分主要为碳酸盐岩的风化溶解。研究区风化过滤、人为活动、原生沉积环境、阳离子交替吸附等因素对地表水和地下水化学成分的贡献率分别为39.1%、15.0%、12.6%、13.8%和19.5%。大通河水的氘和氧同位素含量沿地下水流向呈富集到贫化趋势。D和O同位素测试结果表明，大通河沿地下水流向的氘和氧同位素含量呈富集到贫化趋势。大通河上游和中游主要由大气降水补给，下游受地质构造影响，受水文地质条件制约，主要是潜水和泉水溢出补给河水，作为地下水的排泄区。
