Groundwater resources and their characteristics in arid lands of Northwestern China
中国西北干旱区的地下水资源及其特征

In this paper the physical geographical setting,the formation and distribution of water resources and their utilizing situations in arid land in Northwestern China are analyzed.The dis-tribution and storing characteristics of groundwater in this region are discussed emphatically.In general,the groundwater resources in the plain area are transformed from water resources(in-cluding precipitation and melted water of snow and glacier)in the mountainous area and the latter is the only source of the former.It is believed that the groundwater in the plain area to-gether with the surface water construct a coherent water resource system,an unique hydrologi-cal unit and a complete water ecological system.Therefore,the features and the regularity of the transformation of the three types of water resources(the precipitation,the surface water,and the ground water)should be fully understood,which will play an important role in the sustainable development of this region.