陇中高原山地－丘陵区黄土地下水循环的同位素水文学研究

甘肃陇中高原，干旱缺水，赋存于黄土中的潜水是山区居民赖以生存的基本生活水源，弥足珍贵。但对地下水如何形成，其补给源、补给方式、更新周期及相互间的水力联系一直未能查明，现有观点争议颇多，成为黄土高原长期悬而未决的理论问题。本项目拟选择典型黄土山地、丘陵地带为重点研究区，黄土地下水及区域降水、河水、剖面土壤水为主要研究对象，H、O同位素及14C、CFCs、T地下水年代学等水文学方法为手段，辅以典型区必要的地下水动态监测。围绕黄土高原降水如何补给潜水，补给方式与更新周期，除降水外是否还有古补给水存在或其它补给源为关键科学问题，研究黄土地下水的补给源、循环更新周期及不同时空分布含水层之间的水力联系，旨在揭示黄土山地干旱缺水地区潜水水文循环理论机制。这一研究对指导国家正在大规模实施的新农村建设战略及用水结构调整，特别是对当地地下水资源合理规划利用及优化管理、山区移民政策的制定有极为重要的指导意义。

Longzhong Loess Plateau, one of the most arid areas in China, the groundwater occurred in loess aquifer is very valuable and becomes the basic water resources for human living. However, some key theoretical questions about groundwater circulation have long been unclear. Many opinions about how the groundwater has been formed, what the recharge source and the main approaches to recharge and circulation periods exist great controversies. Thus, in this program, some typical loess mountains and highlands will be selected as basic research area. Groundwater in loess aquifers and soil water in loess sections, regional precipitation, rivers will be collected as research samples. Isotope hydrology of stable hydrogen and oxygen isotopic tracing as well as radio-carbon 14, tritium and CFCs dating will be utilized as main research methods. The program will focus on uncovering the formation and circulation mechanism of the loess groundwater and answering the disputed questions of groundwater recharge source, circulation periods and hydraulic connections between different aquifers in the space or time. The expected research findings will be significant to help state well carry out the New Country Foundation Strategy and adjust structure of water utilization. Moreover, it will also provide some practical advice on regional reasonable exploration and manage water resources and attract residents rightly emigrate in arid loess plateau.