Streamflow Variations and Flow-Break Causes of Four Source Rivers and Mainstream of Tarim River,Xinjiang in 2008

The Tarim Basin is the biggest arid inland basin in China.It is located in Asia European Continent and far away from the sea.The Aksu,Hotan,Yarkant and Kaidu-Konque Rivers are four source rivers of Tarim River drainage.The three tributary river systems(Aksu,Hotan and Yarkant) that contribute flows to the Tarim River join just above the Aler gauging station where the Tarim River begins.From the confluence of its three main contributing tributaries,the Tarim River mainstream extends 1321 km to Taitema Lake.In addition the Kaidu-Konque River Basin,which is hydrologically separate from the Tarim River,contributes water to the Tarim River by means of a manmade transfer channel.In 2008,annual virgin flow of 241.8×108 m3 from four mountains basins of Aksu,Hotan,Yarkant and Kaidu Konque Rivers drain into the Tarim Basin,more 11.5 % than average annual streamflow,is an abundant hydrological year.The annual total virgin flow of Aksu,Hotan and Yarkant above the Aler gauging station are 202.5×108 m3 from the mountains basins,and of the Kaidu-Konque River from Tianshan Mountains 38.83×108 m3.The total discharge of the four source rivers into Tarim River is 29.52×108 m3 in 2008,which three tributary river systems(Aksu,Hotan and Yarkant) contributes 24.74×108 m3 flows to the Tarim River.Most of this water is consumptively used before reaching the confluence.Yarkant is only river no water drain into the mainstream of Tarim Rive.The interzone consumed water of the Tarim River mainstream are estimated to be 21.11×108 m3 for the upper course,the largest consumed section of the Tarim River mainstream;7.63×108 m3 for the middle course,and 0.46×108 m3 for the downstream course.The consumed water of the Tarim River mainstream is too large to emergency water diversion temporarily to downstream for ecological environment in 2008.