Once the eastern gateway to the Silk Road, the Hexi corridor lies between the Qilian mountains to the south-west, and lower mountains bordering the Gobi desert to the north-east. It once was an important trading and military route into Central Asia.
In the extremely arid area, the water table began to rise unexpectedly in 2003 and floods have been frequent since 2005, according to Chi-Yuen Wang, a geologist and hydrologist at the University of California, Berkeley. Wang and a hydrology colleague — Jian Sheng Chen of Hohai University in Nanjing — determined that most of the additional water appears to be coming from glaciers in the surrounding mountains.
Because precipitation at high altitude has not increased significantly in recent years, Wang told New Scientist, it is very likely that the extra water in the Hexi corridor has come from increased glacier melt. The cities of Zhangye and Jiuquan have flooded repeatedly in the past few years, the researchers said, and families have been forced to evacuate.
The researchers say the situation is unlikely to improve; that most of the glaciers along the Hexi corridor are predicted to disappear by 2050; and that the region desperately needs new ways of managing its water supply. Some 26 million people live along the corridor and rely on the mountain springs for water.
See full story