THE RECENT CHANGES OF LAKES AND DRAINAGE SYSTEMS IN THE SOUTH PIEDMONT OF WEST KUNLUN MTS., CHINA
Wang Fubao Cao Qiongying (Department of Geo and Ocean Sciences, Nanjing University) Liu Futao (Changchun Institute of Geography, Chinese Academy of Sciences)
West Kunlun Mts. is one of the centers of present-day glaciers in China. Glaciers, lakes, and drainage system in the region have changed greatly since the middle late-Pleistocene as the global climate changing and the Qinghai-Xizang Plateau rising. Radiocarbon dates of lacustrine sediments and geomorphological survey of the ancient lake shorelines show that the lakes in the south piedment of West Kunlun Mts. have suffered strong drops of water level and separated into a number of small ones in the past 50 000 a. However, these lake level drops were fluctuating, and high level status in the following time periods, around 46 000, 39 000—24 000, 22 000—18 500, 16 000—13 000, 11 000—9 000, 6 000 and 4 500-3 500 a B.P. are identified. Streams in the piedmont region were parts of the upper reach of the Kalakashew River, a side river of the Hetian River in the early time, then changed into interior rivers as Kunlun Mts. rising and climate becoming drier.