Glacier Change of China during the Last 50 Years As Revealed By Glacier Inventories

Thursday, 18 December 2014: 3:20 PM
Shiyin Liu1, Wanqin Guo2, Xiaojun Yao3, Junli Xu2, Donghui Shangguan2, Junfeng Wei2, Qiao Liu4, Xin Wang5 and Zongli Jiang5, (1)CAREERI/CAS Cold and Arid Regions Environmental and Engineering Research Institute, State Key Laboratory of Cryospheric Sciences, Lanzhou, China, (2)CAREERI/CAS Cold and Arid Regions Environmental and Engineering Research Institute, Lanzhou, China, (3)Geography and Environment College, Northwest Normal University, Lanzhou, China, (4)IMHE Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China, (5)Department of Geography, Hunan University of Science, and Technology, Xiangtan, China
The study is based on a new glacier inventory derived from the recent Landsat TM/ETM+ and ASTER images and the modified first glacier inventory from topographical maps of China. Results indicate that glaciers have been generally in retreat during the late 1950s when there were available maps and ~2010, with very few glaciers in advance. The sample glaciers with two inventories covering 83% of the total area of glaciers first mapped during late 1950s and early 1980s have lost 18.1% of their total area in the past 50 years with an annual rate of -0.54%/a or -243.7 km2/a. Some small glaciers have vanished and some large glaciers have disintegrated into several small glaciers. Of all the mountains in China, glaciers in Altai, Gandise and Sawir Mountains are those with the largest area reduction, over 1/3 of the area of their glaciers in the time of first glacier inventory has disappeared, while the area reduction by 20~30% has been found for glaciers in Himalaya, Tangula, Nyainqêntanglha, Tianshan, eastern Pamir, Qilian and Hengduan Mountains. Glaciers in Karakoram, Kunlun (including Altun) and the central Tibetan Plateau are among the least decrease in area of all glaciers in China, their shrinkages are 11.3~ to 8.4%. The spatial pattern is also confirmed while expressing the area reduction of glaciers in annual percentage, i.e., glaciers of the Qangtang Plateau of the Tibetan Plateau show the smallest shrinkage with gradual increase in annual reduction rate in the surrounding mountains over the Tibetan Plateau. We have measured length changes of >1500 glaciers with a total area of 19628km2, 12.7 km2 in average. Only 53 glaciers with average area of 32.8 km2 displayed the obvious advance during the last 50 years. All glaciers with length measurements have lost 8.7% of their total area in the considered period. All advancing glaciers are mostly located in the Tianshan, eastern Pamir, Karakoram and Kunlun Mountains, with 18 glaciers in Karakoram with almost double annual rate of 17.7m/a compared to 9.6m/a of advancing glaciers in other mountains. The big glaciers might experience less area shrinkage, for example, 65 glaciers larger than 50 km2 in China have lost a total area of 577 km2, -3.8% or -0.1%/a. The general retreat of glaciers may be a result of the regional warming especially during the recent 20 years in western China.