Influence of climate change on saline lakes of the Tibet Plateau, 1973-2010

- We delineated surface extents of 93 salt lakes with areas larger than 20 km2 on the Tibet Plateau from Landsat images.
- Dynamic changes of saline lake surface area were analyzed.
- Over the past forty years, the climate of the Tibet Plateau has changed, becoming warmer and wetter.
- New analyses included factors responsible for the changes, i.e., tectonics, climate, lake basin shape, glaciers, and human activities.

Levels and surface areas of saline lakes are indicators of climate change and climate variability. The surface extents of 93 saline lakes with areas larger than 20 km2, excluding dry saline lakes, on the Tibet Plateau were delineated from Landsat images obtained in 1973-1977, 1989-1992, 1999-2001, and 2008-2010 based on remote sensing spatial analysis techniques and GIS. The dynamic changes of the saline lake surface areas from 1973 to 2010 were analyzed. The total surface area of these saline lakes increased, especially since around 2000, and the total surface area increased by 47% during 1973-1977 to 2008-2010. During 1973-1977 to 1989-1992, saline lakes with decreased areas were mainly distributed in the northern and middle parts of the Tibet Plateau, whereas those in other places tended to expand; since around 2000, nearly all the saline lakes expanded. Mean annual temperature, mean annual maximum temperature, mean annual minimum temperature, annual precipitation and evaporation on the Tibet Plateau were analyzed. Over the past four decades, the climate has become warmer and wetter. Rising temperature and dropping evaporation are two dominant factors responsible for saline lake expansion. The salinity of many saline lakes decreased during this climate warming. New analyses included factors responsible for the changes, i.e., tectonics, climate, lake basin shape, glaciers, catchments, open or closed systems and human activities.