The Kumarik River , which is the head-water of the Aksu River and from the glaciated centre of Central Asia in the Mount Khan Tengry of Tianshan , drainage area of 12 816 km² (which of 2 306 km² in Kyrgyzstan) in which glacier area is 3 195 km² . Inylchek Glacier is the largest one with 61km length and an area cover of 748. 4 km² . The glacial runoff is 54% of average annual runoff at Shehel Gauge Station. In the source region of Kumarik River , sandwiched between the South and the North Inylchek Glaciers , is the mysterious Merzbacher Lake , which is the largest glacial lake in SaryJaz-Kumarik River Basin. Every year , and sometimes twice a year , the lake suddenly empties , only to refill again with the melted glaciers that surround. Merzbacher Lake glacial flash flood occurred 62 times and more than 90% frequency in the period of 1932 -2008. Glaciers melt and glacier flash floods play a vital role in runoff supply and flood control security for the Aksu River and the Tarim River in China. Over the past year s , the Tianshan have started melting down with the increase in temperature leading to formation of increasing number of glacier-fed lakes. The total discharge of glacier flash floods is increasing to 3 ×108 ～ 4 ×108 m³ in 1990s from 1 ×108 m³ of 1960s - 1970s , and the total flood volume is up to 4. 5 ×108 m³ . The Peak discharge has increased 32 % from 1950s to 1990s. Glacier flash floods drainage in Merzbacher Lake by the river way under the ice to downstream and the flood period often lasted a few days to more than two weeks. The changes in glacier mass balance in the Kumarik River Basin have significantly influences on glacial flash flood , the more glacier melt , t he larger the peak discharge. With climate warming , t he pressure of flood control is increasing in the lower reaches of the Aksu River . Therefore , it is vital to strengthen t he observation and monitoring of the glaciers and the water levels of glacial lake , establish early warning systems for the orecasting of glacial lake out burst flood and downstream security.