摘要
气候变暖是全球性问题,而西藏对全球变化的响应尤为剧烈。以西藏冰冻圈为研究对象,在已有研究成果基础上,论述了西藏冰冻圈的消融退缩与全球气候变化之间的关系,认为西藏冰冻圈消融与退缩是对全球气候变暖的直接响应。西藏冰冻圈的消融退缩对该区生态环境产生了重要影响,主要包括:冰川消融直接导致了河川径流量变化以及冰川型泥石流、冰湖溃决等灾害的频发;高原冻土层的消融导致了冻融侵蚀增强、高寒草甸以及高寒沼泽草甸的退化和种群演替,同时还导致了地表向干化方向发展,加剧了区域荒漠化趋势。
Global warming,having a deep impact on the global ecological system,has inevitably induced changes in the cryosphere,one of the five earth layers.Major changes are as follows: the shrinking and reducing of the coverage and volume of icecap covering North and South poles and mountain glaciers,the melting of permafrost and thickening of the frost layer.The cryosphere swifts as mentioned above have inevitably necessitated ecological and environmental changes in its zone.While some of these changes are of benefit to mankind,such as the increased water circulation,water volume increase in a short term and the enlargement of plantable zone,most others are hazardous to mankind like the lowland flooding caused by the elevation of sea level,debris flow caused by glaciers,glacier lake bursts,undermined building safety caused by permafrost melting,the deterioration of alpine cold meadow,land drying and desertification.Tibet,a major part of the cryosphere in China,is home to the most widely spread glaciers and permafrost,which play a vital role in water resources,climate environment and ecological safety in China and Asia at large.However,due to the global warming,the glaciers and permafrost in Tibet have recently changed dramatically featured by shrinkage and melting,which has threatened the water resource,ecological and environmental safety.Based on the existing research results,this paper discusses the relationship between climate warming and cryosphere's melting and shrinkage.The result shows that the cryosphere's melting and shrinkage in Tibet are the direct result of the global climate warming.The melting of glaciers led to a series of disasters,such as river runoff change,the heightened frequency of debris flow induced by glaciers and glacier lake outbursts;The permafrost melting also resulted in a series of ecological and environmental problems in Tibet,such as degradation and population succession of the alpine grassland and alpine meadow and moor,drying and desertifying of the land surface,and the heightened
出处
《干旱区地理》
CSCD
北大核心
2010年第5期703-709,共7页
Arid Land Geography
基金
西藏自治区科技厅科技专项"西藏高原拉萨市区土壤侵蚀分类分级研究"
国家科技支撑计划项目"西藏高原国家生态安全屏障保护和建设关键技术研究与示范(2007BAC06B06)"资助
关键词
西藏
冰冻圈
气候变暖
生态环境
Tibet
cryosphere
global warming
ecological environment