Recent glacial retreat and its effect on water resources in eastern Xinjiang

Abstract

The eastern Xinjiang Basin is desperately short of water. Most rivers in the basin originate in the high eastern Tianshan, which has abundant precipitation and numerous alpine glaciers. Fieldwork conducted on three reference glaciers around Mt. Bogda in 1981 and suggests that they all strongly melt in summer, a process that has tended to accelerate in recent decades. Based on topographic maps from 1962 and 1972 and 2005/2006 . South-facing glaciers lost more of their area than those that are north facing, yielding an areal loss of 25.3% and 16.9% for southern and northern slopes of Mt. Bogda, respectively, and 12.3% and 6.6% for the comparable slopes of Mt. Harlik. Glaciers smaller than 0.5 km 2 in area experienced the strongest retreat, whereas glaciers larger than 2 km 2 in area experienced gentle recession but may be the main contributors in the future to river runoff. Glacial ablation in eastern Xinjiang tends to be strong, and the water resources in this region are deteriorating. Also, a heavy reduction in the capacity of the local karez system, as well as a significant change in river runoff, can be related to glacial retreat. Combined, this will adversely affect the downstream city of Urumqi and the Turfan Basin. Climate change is of great concern the world over, particularly regarding the effect of humanity on the existing environment and vice versa. Under continued warming over the last several decades, alpine glacier retreat has accelerated. Surface melting has occurred even on high-altitude glaciers [1]. Moreover, about 75% of the fresh water of the world comes from glaciers [2], thus retreating glaciers will have a strong influence on the regional hydrologic balance and economic sustainability. Climate warming, regardless of whether it is caused by anthropogenic factors or by nature, has led to strong global glacier recession. In fact, changes in alpine glaciers are one of the best natural indicators of climate change because a small change in climatic parameters will result in pronounced geometric changes in glacier shape and size. Many studies show that strong glacial wastage has been the major trend [3,4] over the period from 1993 to 2003 during which time sea level has risen about 0.77 ± 0.18 mm as a result, primarily, of that glacier melting [5]. Using two climate models, sea level is estimated to rise 0.046 m and 0.051 m as a result of mountain glaciers and ice caps melting by 2100 [6]. The estimate of China's potential contribution to cryospheric change is a sea level rise of 0.14-0.16 mm a 1 , of which the contribution of meltwaters from glaciers is assessed at about 0.12 mm a 1 [7]. The problems associated with strong mountain glacier melt are glacial hazards such as glacial lake outburst floods and

Mapping changes in the glaciers of the eastern Tienshan Mountains during 1977–2013 using multitemporal remote sensing

“…Because the snow layer temperatures are high, the same amount of melting glacier consumed a lower amount of energy, thereby increasing the sensitivity of the glacier to air temperature rise. 36 An increase in precipitation creates a favorable condition for the accumulation of glaciers. Because the main glacier ablation period is in summer, the increase of the summer temperature causes an increase in the liquid precipitation but not in the solid precipitation, thus causing the glacier mass income to decrease and the glacier retreat to excelerate.…”

The hydrological linkage of mountains and plains in the arid region of northwest China

“…With global climate warming and population explosion, water resources in mountains are facing a severe test. The rise of temperature cause glaciers retreat dramatically [21][22][23]. In the coming short period, the contribution of glacier melt water to basinal runoff perhaps will increase, but in the long run, the compensation capacity of melt water is bound to gradually reduce .…”

Methodologies and applications in Digital China

“…Li et al [42] studied the effects of glacier retreat on the water resources in eastern Xinjiang basin. They analyzed, through maps and imagery data, a total of 278 glaciers around Mount Bogda and Mount Harlik and further correlated the water shortage in eastern Xinjiang with the physical changes in the glaciers caused by retreat and recession due to global warming phenomenon.…”