Glacier Change and Its Impact on Water Resources

Abstract

Glaciers play an extremely important role both on water resource and stabilization of river runoff in this northwest arid region of China. Urumqi Glacier No.1, located at the head water of Urumqi River is the monitored glacier with the longest continuous history of any glacier in China. The glacier has experienced remarkable shrinkage from 1962 to 2009. Its length has shortened by about 215.2 m (9.7 %) and its area has diminished by 0.304 km2 (15.6 %). The cumulative mass balance of the glacier was − 13,693 mm, equivalent to 15.2 m of glacier ice, showing particular sensitivity to temperature change. Annual glacier melt runoff and discharge at gauging site have also exhibited increasing trends. The volume of glaciers in Xinjiang is about 23,611.2 × 108 m3 water equivalent and rank first in the country. It is extremely sensitive of glaciers in Xinjiang to climate change. As temperatures rise, the melting of glaciers is accelerated and the meltwater runoff has increased to over 200 × 108 m3, accounting for more than 25 % of the quantity of surface water 789 × 108 m3. Due to serious melting, glacier area reduced by 11.7 % in the recent 30 years and the volume loss is more rapid. Changes of the spatial and temporal distribution of water resources and process of hydrologic cycle initiated by glacier changes will exercises a great influence on construction layout of Xinjiang and development patterns, which has attracted the common concern from the governments from central to local and people. It has been one of the important problems that needed to be solved in the pace of development and construction of Xinjiang nowadays. For the Qilian Mountains, water stress and ecological problems are bottlenecks of social economic development. All of glaciers, seasonal snow and permafrost water resources account for the vast majority in the components of water resources. Among them, glacier is the most active factor because of its high sensitivity, river runoff regulate effect and feedback mechanisms of mountain climate. One thousand and seventy-eight glaciers in the middle of Qilian Mountains, including Heihe River Basin and Beidahe River Basin with the area of 420.55 km2 are studied. Areas of these glaciers have reduced by 21.7 % in the past 50 years. It is estimated that glacier meltwater runoff account for over 10 % of river runoff and play an important role in the stabilization of river runoff, regulation of annual change and allocation.