应用环境同位素方法测定了不同类型地下水的年龄，识别了西北干旱、半干旱地区地下水的补给源，进行了补给量的计算，建立了地下水流系统，并取得了新的成果。 The isotope method was used to determine the age of different types of groundwater. The recharge sources of groundwater in the arid and semi-arid regions of Northwest China were identified. The recharge amount was calculated. The groundwater flow system was established and new achievements were achieved.