Changes of rivers and lakes on the Qinghai-Tibet Plateau in the past 25 years and their influence factors

The present status and changes of distribution of rivers and lakes on the Qinghai-Tibet Plateau in the past 25 years have been analyzed according to the interpretation of the MSS remote sensing images in the middle 1970s and the ETM+ images at the end of the 1990s. Study indicates that: in general there is no appreciable change of rivers on the Qinghai-Tibet Plateau; a few river stretches of exterior drainages in some areas fluctuate slightly and a few river stretches of interior drainages are diverted or run dry; the river-mouth stretches where rivers inflow into lake show extensional and recessional changes. Most natural lakes on the plateau change significantly, mainly manifested by the following aspects: some lakes are reduced or expanded in area, some lakes are disintegrated or merged, water are again collected in some dried-up, and some lakes are nearly dried-up. The main influence factors leading to the changes of rivers and lakes include air temperature change, precipitation change, glacier change and climatic snow line change.