Variations And Characters Of Glacier And Glacial Lakesin Altai Mountains In Recent 25 Years

As the population increased,and social and economic developed,demand for fresh water resource of human society was increasing.Under the background of global warming,the aggravation of glacial retreat changed water from solidity into liquite which could be used by,on the one hand.On the other hand,the water yield disembogued into basin increased,which broked the material balance of water cycle.Then the expansion trend of glacial lake became obvious,and disasters such as glacial lake burst,landslide and debris flow,increased.Hence,monitoring and researching change of glaciers and glacial lakes in typical region has theoretical and realistic significance.Northwest area of China is inland,poor in precipitation lack of fresh water.The Altai Mountains in this area is surrounded by glaciers and glacial lakes,with abundant freshwater resources,which is important source of fresh water of this area.This study analyzed the characters of geological landforms,climate and hydrology of the Altai Mountains first,then picked out the image data of the Alty Mountains in 1990,2000 and 2015,based on Landsat TM/ETM+image data,by the method of artificial visual interpretation,catalogued glaciers and glacial lakes of the mountains,and analyzed the changes and change characters of the glaciers and glacial lakes in Altay region between 1990 to 2015.The result showed:the area of glaciers decreased 127.55 km~2,retreated 0.59%a-1 per year on average.The rate of glacial recession was fast in east orientation and slow in west orientation,and the former was almost twice as fast as the latter.The area of glacial lakes in the Alty Mountains increased 30.029 km~2,on an average increase of 0.58%a-1.The increase of the area of the glacial lakes mainly due to the new glacial lakes.The area of the glacial lakes at various elevations all appeared expanding trend,while the region where the area of the glacial lakes decreased were mainly distributed at relatively lower elevations(<2100m)and high elevations(>3000m),the area of the glacial lakes at the elevation between 2100m to3000m expanded rapidly,in which the rapidest growth is the elevation between 2400m to2700m,the net appreciation can be 3.20km~2-4.31 km~2,occupying 49.8%of the net increased area of the glacial lakes.The expansion rate of the glacial lakes varied in the regions studied,the amount of glacial lakes increased fastest in north orientation,and the area increased biggest in northwest orientation.The Expansion of the glacial lakes resulted from the interaction of glacial recession and climatic change in the region...