The Research Of Glacier Change In The Yulong Snow Mountains Based On RS And Observation Data

Glacier change is the direct result of climate change and has obvious response on climate change in return. Under the background of global warming, the response of temperature glacier to climate change will become more sensitive and directed. On the base of data material including remote sensing image, DEM and glacier variations, this paper mainly studied the 52-year glacier changes in Yulong Snow Mts. through the application of computer, GIS, and remote sensing. Through observation data, weather station data and snow pits, the mass balance was calculated on the Baishui glacier No.1. The degree day model was analyzed and demonstrated to be feasible and practical in this area (the feasibility and application of it in research region). Some conclusions are drawn as follows:(1) In the present study, we investigated the changes of glaciers from Yulong snow Mts. in the Hengduan Mts. by using aerial photos (1957), Landsat TM (2001, 2009) imageries, topographic map and DEM. Comparing with data in 1957 from China Glacier Inventory, the results indicate that since 1957, glacier recession became very fast and universal during the period from 1957 to 2009. A comparative analysis of glacier length/area variations between 1957 and 2009 on Yulong snow Mts. shows that the area reduced to 4.42km2 in 2009, with the annual diminution rate of up to 1.19%. The average of glacier terminus altitude has increased by 221m, with the annual elevation of 4.25m.6 glaciers have entirely disappeared since 1957. Climatic warming was the major reason for glacier retreat in this area.(2) From September 2008 to September 2010, Yulong Glacial and Environment Observation Station made a new observation about accumulation-ablation cycle of the mass balance on the Baishui Glacier No.1 on the Yulong Snow Mts. The observation results show that accumulation of the glacier mainly concentrated from the mid-October to next April, and glacial ablation mainly happened from May to mid-October. The mass balance of the glacier was -1047mm and -1467mm in 2008/2009 and 2009/2010 respectively. The glacier change has characterized by larger negative mass balance, and the equilibrium line had been going up at the same time, reflecting the response of Baishui No.1 glacier to Global Climate Change. Combined with the measured data of glacier terminus in recent ten years, supposing the tendency of global warming continues, the negative value of glacier mass balance will constantly increase, which means glacier thinning and snow lines rising, glacier area will continue to decrease in size.(3) Based on observed mass balance and meteorological data since September 2008 and ablation data obtained by the expedition team of Tibetan plateau from June to August 1982 at the Baishui Glacier No.l region, we analyzed the spatial and temporal changes of degree-day factor (DDF) of the Baishui Glacier No.1. As an important parameter of degree-day model, the research of DDF is a discovery for application of degree-day model, following the changes of space, time, and temperature, which lays a theoretical foundation to establish DDF model. The results demonstrate clearly that the melting DDF of ice showed a significant downward trend with rising temperatures, and larger value of DDF only appeared at low temperature conditions. A larger value of DDF appeared in the high altitude areas, and as altitude rises,the value of DDF increased. The snow DDF is lower than the DDF of ice, and the DDF is higher in temperate glaciers than that in other glaciers. The melting DDF of snow has a more obvious seasonal variation than the melting DDF of ice.