中文摘要：

综合应用水文地球化学指标和稳定同位素技术研究了党河流域敦煌盆地地下水补给和演化规律。岩盐、石膏及芒硝等矿物的溶解对Na^＋、Ca^2＋、Cl^-及SO4^2-离子浓度影响较大。阳离子交换作用明显,地下水中Mg^2＋和Ca^2＋浓度增加,并与碳酸盐发生沉淀,导致HCO3~-减少。地下水的δ^18值介于-12.1‰~-7.5‰,δ^2值变化范围为-84.3‰~-61.5‰,指示了盆地不同地带地下水补给来源不同。潜水δ^18和δ^2数值随着地下水径流路径方自西南到东北越来越富集,反映了蒸发浓缩效应,南湖、盆地南部潜水同位素与河水相近,体现了现代补给。相比之下,承压水稳定同位素相对贫乏,指示过去寒冷时期的补给。该研究可以为敦煌区域地下水资源规划和管理提供一定的借鉴意义。

英文摘要：

The groundwater supply in arid areas played a pivotal role in many fields. Firstly,it is closely related with some environmental problems such as desertification,storms and salinization. Secondly,it is a very important factor to control the economic development especially for the irrigation agriculture. The Dunhuang Basin,located in the Danghe River Basin,is facing serious groundwater problems. Additionally,tourism industry in this region is very developed but the ecological environment is rather fragile,therefore,to get an insight into the characteristics of groundwater in this region is the precondition for solving the groundwater problems. The groundwater water chemical type is a concentrated reflection of the groundwater chemical composition,and a system response of the whole water and groundwater circulation characteristics. Studies of the variation characteristics and the evolution of groundwater can better reveal the interaction mechanism of groundwater and environment. By using hydro-chemical and stable isotopic technology,this paper determined the evolution way of ground water hydro-chemical characteristics,the recharge environment of groundwater in the study area,and the physical and chemical properties of groundwater. Results show that the quality of groundwater and surface water was generally good with low salinity and unpolluted. The relationships between Na＋and SO4^2-,Cl^-and Na＋,as well as Ca^2＋ and SO4^2- were quite good,indicating that the dissolution of rock salt,glauber＇s salt and gypsum had great influences on the concertration of Ca^2＋,Na＋,SO4^2- and Cl^-. Reverse cation exchange played an important role in the concentration of Ca^2＋and Mg^2＋,and with the increase of Ca^2＋and Mg^2＋in groundwater,carbonate started to precipitation,leading to a reduction of HCO3^-. This reaction was accelerated by the preceding hydro-geochemical evolution,especially the dissolution of the glauber＇s salt. The increase of Na＋can cause the cation exchange between Na^＋ of the groundwater a