南水北调西线一期工程区水文地质条件评价

针对南水北调西线一期工程区地形、地质、地貌和气候条件复杂,及工作条件差、工期短、基础资料缺乏等特点,建立了以遥感水文地质判释为主,结合野外地面调查、现场钻孔地下水流速流向测试、现场钻孔压水试验资料分析、水化学分析、环境同位素测试分析等多手段多方法的水文地质条件综合评价方法,研究了该工程区的地下水类型、地下水化学特征及其形成条件、主要含水层的分布,主要水文地质单元及其地下水运动和补径排条件。结合水利工程勘探的特点,充分利用钻孔压水试验成果,分析探讨水文地质参数及其变化特征,对沿线隧洞涌水量进行初步估算。探讨了主要的水文地质问题。为高山覆盖地区的水文地质条件研究提供了一种新思路。

EVALUATIONS FOR HYDROGEOLOGICAL CONDITIONS ALONG WEST ROUTE OF SOUTH-TO-NORTH WATER TRANSFER PROJECT

In the region of the west route of South-to-North Water Transfer Project in China,the topographical,geological and climatic conditions are very complicated and the field investigations are also very difficult to be performed.With the consideration of the above reasons and limit research time,an integrated evaluation method is developed to study the related hydrogeological conditions of the region,in which the remote sensing technique is mainly adopted with combination of field ground surface investigation,environmental isotope research,field data analysis of borehole water pressure test and isotope trace test,hydrogeochemical analysis of groundwater from springs,and numerical modeling,etc..The hydrogeological conditions of west route region in the South-to-North Water Transfer Project are also studied,such as the major types of groundwater and the geochemical properties,the spatial distribution of main aquifers,the main hydrogeological elements and the relations among supply-runoff-drainage,groundwater movement,etc..There are two main aquifers in the region:the pore aquifer and the weathered fracture aquifer with a large groundwater runoff intensity caused by physical weathering process.It is the basic hydrological characteristics that there is an active deep groundwater cycle through tectonic fractures and faults with rich water storage.Considering the application to the hydraulic engineering,the hydrogeological parameters are also investigated.The possible water quantities flowing into tunnel are finally studied;and the possible hydrogeological problems of the engineering are presented.The water flow from rock mass into tunnel will be the main hydrogeological problem.The research also provides a new way to evaluate the hydrogeological conditions for the region covered by high mountains.