Wei-Zu Gu¹ and Mebus A. Geyh²

¹ Nanjing Institute of Hydrology and Water Resources, Nanjing, China
² Geological Survey of Lower Saxony, Hannover, Germany

Alxa Plateau, the west part of the Inner Mongolia, is one of the most arid area of China. It includes various geomorphological units, the Gobi of about 12000 km², Gurinai grassland of about 3000 km2 and the Badain Jaran Desert of 44300 km². The Black River (Ruo Shui) flows across its west part and ends into lakes. Aimed at its water resources evaluation, phreatic and confined groundwater were sampled for all the wells and springs which could be found during expeditions from 1987 to 1999 including several sites in the Gobi area of Mongolia Republic.

Looking at the hydrochemical facies of both the phreatic and confined groundwater of the Gobi area with ancient city ruins, the Gurinai grassland and, that of the confined groundwater of Badain Jaran Desert and that of the Black River water it is presumed that:

• Precipitation recharge still exist in this extreme arid region with annual precipitation only about 50 mm.
• A relationship between the percolation of Black River and the confined groundwater of the Gobi area appears to exist, but it seems that no significant relations exist with the Gurinai groundwaters.
• The groundwater at the south of Altai Mountains of Mongolia appears to be related with the confined groundwater of the Gobi and Ejina area.
• The confined groundwater of the Badain Jaran Desert may be one of the groundwater sources of the confined groundwater of the Gurinai and, very likely of the Gobi area.

** Copies of the full paper are available for distribution.