Reason Analyses And Strategies For The Water Tabel Drop-off Of The Qinghai Lake

The Qinghai Lake located in the northeast of the Qinghai-Tibetan planteau has surface area of 4282.3 km2 and catchment area of 31200 km2. It is an important water system to maintain ecology safety of northeast Qinghai-Tibetan Planteau, a world-known damp land, the natural preserve region, water and gas sources of high arid area as well as demonstrated base of high-efficient farming and livestock production in Qinghai province For many decades, the water table has been lowering due to changes of weather and natural envionment. Between 1959-2000, its water table descended 3.35 m. The mean annual drop-off of 8.2cm has resulted in the ecological environment deterioration, affected the ecological environment and farming and livestock production in the Yangtze River and the Yellow River source areas, in the Chaidamu Basin, in the east of the Qilian Mountain and in the Huangshui valley of east Qinghai.Study on the reason and strategies of the Qinghai Lake's water table drop-off is of significances for improving ecological environment in the Qinghai Lake area, reducing the drop-off speed of water table, maintaining ecological safety of northeast Qinghai-Tibetan plateau, obstructing desertification spread ofthe west and ensuring the sustainable development of the regional economy.The paper aims at analyzing the historical evolution of the Qinghai Lake and the data from observing and measuring between 1959 - 2000 and research materials, studying the changing trend of the Qinghai Lake's water table and the cause of the drop-off, carrying out the balance calculation of 42-year water volume in the lake area in accordance with information on fundmental situation and monitoring data of the Qinghai Lake and its catchment area, thereby, proving that the major reason of the water table drop-off and the water volume reducing in the lake has resulted from the warm and dry weather for aproximately ten decades.Based on the above-mentioned reason, the paper will put forward to some strategies, which include: strengthening water resources management in near future, conserving the water source, enlarging vegetation construction, retreating farming land into forest and grassland by big margin, carrying out comprehensive control with a combinition of water and soil conservation.engineering measures and building the ecological oasis in order to decrease the drop-off speed of the Qinghai Lake's water table. In a long run, the implementation of water divertion project such as "Diverting Water from Datong River to the Lake" is the fundamental measure to resolve the problem of the Qinghai Lake's water table drop-off and to conduct ecological environmental construction.