Mountains have been described as the water towers of the world. Almost all major rivers have their sources in mountains; glaciers are important water resources that contribute meltwater to river discharge. Glaciers participate in the global water cycle and, with their solid water storage, are an important component of the water balance. As solid reservoirs, glaciers continue to receive the mass nourishment of solid precipitation from the atmosphere, and their meltwater feed and regulate fiver discharge. Physical changes in glaciers are an indicator of climate change. Over the past half century, the global temperature has increased by 1-2 ℃, which emphasizes the urgent task of monitoring glaciers and predicting their trend. As an example, we have investigated, researched, and surveyed Glacier No. 1 in the Urumqi River source, Tianshan （abbr. Glacier No. 1 Tianshan or Glacier No.l） for half a century. We have found an increase by degrees of the glacial regression during the last 400 years and discovered a terminal moraine which is forming today. The global temperature is rising continually, while the local glacial temperature is 0.4 times that of the global temperature change. Thus, we forecast that Glacier No. 1 Tianshan will disappear during the late 21 st Century （2074-2100 A.D.）.
The Yangtze River Source Region has an area of 137,704 km2.Its mean annual runoff of 12.52 billion m3,which was recorded by the Chumda Hydrological Station in 1961–2000,accounts for only 0.13 percent of the Yangtze River's total annual streamflow.The extensive rivers,lakes,wetlands,glaciers,snow fields,and permafrost of the Yangtze River Source Region,as well as the region's vast alpine grasslands,play a critical role in storing and regulating the flow of water not only in the upper Yangtze River watershed of Qinghai,Sichuan,the Tibet Autonomous Region (TAR) (Tibet) and Yunnan,but also throughout the entire lower Yangtze River basin.Climate change has been the dominant factor in recent fluctuation in the volume of the Yangtze River Source Region's glacier resources.The Chumda Hydrological Station on the lower Tongtian River has registered a mean annual glacial meltwater of 1.13 billion m3 for the period 1961–2000,makes up 9 percent of the total annual runoff.Glacial meltwater makes up a significant percentage of streamflow in the Yangtze River Source Region,the major rivers of the upper Yangtze River Source Region:the Togto,Dam Chu,Garchu,and Bi Chu (Bu Chu) rivers all originate at large glaciers along the Tanggula Range.Glaciers in the Yangtze River Source Region are typical continental-type glaciers with most glacial meltwater flow occurring June–August;the close correlation between June–August river flows and temperature illustrates the important role of glacial meltwater in feeding rivers.Glaciers in the source region have undergone a long period of rapid ablation beginning in 1993.Examination of flow and temperature data for the 1961–2000 period shows that the annual melting period for glacial ice,snow,and frozen ground in the Yangtze River Source Region now begins earlier because of increasing spring temperatures,resulting in the reduction of summer flood season peak runoffs;meanwhile,increased rates of glacier ablation have resulted in more uneven annual distribution of runoff in the source regio
YongPing ShenGuoYa WangGenXu WangJianChen PuXin Wang
