Acta Geographica Sinica ›› 2013, Vol. 68 ›› Issue (7): 886-896.

### Spatial-temporal variations of lake area in Hoh Xil region in the past 40 years

YAO Xiaojun1,2, LIU Shiyin2, LI Long1, SUN Meiping1, LUO Jing1, FENG Yaya1

1. 1. College of Geography and Environment Sciences, Northwest Normal University, Lanzhou 730070, China;
2. State Key Laboratory of Cryosphere Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou 730000, China
• Received:2013-03-21 Revised:2013-04-16 Online:2013-07-27 Published:2013-07-27
• Supported by:
National Natural Science Foundation of China, No.41190084; National Science-technology Support Plan Project, No.2012BAC19B07; National Natural Science Foundation of China, No.41071044; No.41261016; Youth Teacher Scientific Capability Promoting Project of Northwest Normal University, No.NWNU-LKQN-10-35

Abstract: As one of the areas with numerous lakes on the Tibetan Plateau, the Hoh Xil region plays an extremely important role in the fragile plateau eco-environment. Based on topographic maps in the 1970s and Landsat TM/ETM+ remote sensing images in the 1990s and the period from 2000 to 2011, the data of 83 lakes with the area above 10 km2 were obtained by digitization method and artificial visual interpretation technology, and the causes for lake variations were also analyzed. Some conclusions can be drawn as follows. (1) From the 1970s to 2011, the lakes in the Hoh Xil region firstly shrank and then expanded. In particular, the area of lakes generally decreased during the 1970s-1990s. Then the lakes expanded during the 1990s-2000 and their area was slightly higher compared with the 1970s. The area of lakes dramatically increased after 2000. (2) From 2000 to 2011, the lakes with different area scales in the Hoh Xil region showed an overall expansion trend. Meanwhile, some regional differences were also discovered. Most of the lakes expanded and were widely distributed in the northern, central and western parts of the region. Some lakes merged together or overflowed due to their rapid expansion. A small number of lakes with the trend of area decrease or strong fluctuation were scattered in the central and southern parts of the study area. And their variations were related to their own supply conditions or hydraulic connection with the downstream lakes or rivers. (3) The increase in precipitation was the dominant factor resulting in the expansion of lakes in the Hoh Xil region. The secondary factor was the increase in melt water from glaciers and frozen soil due to climate warming.