Characteristics and changes of streamflow on the Tibetan Plateau: A review

Study region: The Tibetan Plateau (TP). Study focus: The TP exerts great influence on regional and global climate through thermal and mechanical forcings. The TP is also the headwater of large Asian rivers that provide water for billions of people and numerous ecosystems. Understanding the characteristics and changes of streamflow on the TP will help manage water resources under changing environment. Three categories of rivers (the Pacific Ocean, the Indian Ocean, and the interior) on the TP were examined for their seasonal and long term change patterns. Outstanding research issues were also identified. New hydrological insights for the region: Streamflow follows the monthly patterns of precipitation and temperature in that all peak in May–September. Streamflow changes are affected by climate change and human activities depending on the basins. Streamflow is precipitation dominated in the northern, eastern and southeastern basins. In the central and western basin either melt water or groundwater, or both contributes significantly to streamflow. Human activities have altered streamflow in the lower reaches of the eastern, northern and western basins. Long-term trends in streamflow vary with basins. Outstanding research issues include: (1) What are the linkages between streamflow and climate systems? (2) What are the basin-wide hydrological processes? And (3) What are the cryospheric change impacts on hydrological processes and water balance?