Oral Presentation NCGRT/IAH Australasian Groundwater Conference 2019

Hydrogeology of inland basins in NW China (61)

Lihe Yin 1
  1. China Geological Survey, Xi'an, Shaanxi, Christmas Island

The inland basins in NW China include the Junggar Basin, the Caidam Basin, the Tarim Basin and the Hexi Corridor, covering an area of about 2.14 million km2. Groundwater is a major water source in these regions; hence China Geological Survey has launched a series of projects to characterize hydrogeological conditions of these basins. This presentation will summarize the main findings of these studies through related reports, papers and monographs review. Annual precipitation is usually less than 100 mm in most areas except the mountainous areas. In contrast, the annual potential evapotranspiration is higher than 1500 mm over the majority of inland basins. Annual the mean annual groundwater recharge is about 49 billion m3, mainly from river water infiltration, irrigation return flow. Groundwater is mainly used for agricultural section, accounting for over 80%, and has been overexploited in some areas, including the Hexi Corridor, the Junggar Basin and the Tarim Basin, resulting in a severe ecological impact, such as tree dieback and wetland shrink. A key character is the frequent transformation of surface water and groundwater, usually at least three times. Groundwater flows through difference systems, i.e., local or regional systems. In the future, more studies are needed, such as the impact of climate change on groundwater resources and water allocation to ecosystem recovery.