Dynamic Changes of Saline Lakes in Xizang and Its Response to Climate Fluctuations from 1973 to 2017
Xizang is one of the main saline lake distribution areas in China.The surface extents of 93 saline lakes,with the area larger than 20 km2,in the study area were delineated from Landsat images obtained in 1970's,1990's,around 2000,around 2010,and 2017 based on RS and GIS.The dynamic changes of these lake surface areas from 1970's to 2017 were analyzed.The results were as followed:(1)The total surface areas of these saline lakes increased by 68%during 1990's to 2017;(2)during 1970's to 1990,saline lakes with area decreasing mainly distributed in the northern and middle parts of Xizang.Since 2000,most lakes have expanded;(3)Dynamic changes of saline lake areas are closely related to climate fluctua-tions.From 1971 to 1990,there were few temperature and rainfall fluctuations,and the decrease of glacier and snowmelt water supply caused the shrinkage of saline lakes in the northern and middle parts of Xizang.From 1991 to 2017,the temperature and rainfall increased while the evaporation decreased,leading to the overall expansion of saline lakes in Xizang.(4)The remote sensing interpretation of Zabuye Salt Lake areas are basically in agreement with the long-term data on water level from the monitoring station.From 1973 to 2009,the water levels of Zabuye Salt Lake showed an overall upward trend,and then,declined.Landsat 8 provides free multi-temporal remote sensing images from 2013,which can be used for continu-ous observation of the saline lake dynamic changes in Xizang.The change of areas and chemical composi-tions of saline lakes should be highlighted in the future research.
XizangSaline lakeRemote sensingDynamic changesZabuye Salt LakeDepth
NETL
NSTL
万方数据
