Bukhtarma Reservoir water availability fluctuations on the China-Kazakh trans-boundary Irtysh River

English Abstract:

Reduction of surface runoff in the Irtysh River Basin in recent decades is leading to disastrous consequences on the aquatic ecosystem in the region. As a result of the runoff reduction the Bukhtarma reservoir and connected Lake Zaysan are experiencing dramatic problems with water availability. The major tributary is the Black Irtysh River with the upstream located in China. The research work is based on data collected for the period 1960 to 2014. We used the water fluctuations of river runoff, water levels and water release from the Bukhtarma reservoir. Scenarios of the future changes were analyzed with analyses of the natural and anthropogenic impacts on the water availability fluctuations on the Bukhtarma reservoir. With the water intake from the Irtysh River estimated at 2 km³ per year, flow decreases by 21.8% compared to the natural conditions in average watered years. When water subtraction is equal to 3 km³ per year, river flow during the dry year can be reduced by 69.0% compared to the natural conditions.