基于RS/GIS的西藏地区湖泊 变化动态监测及气候背景

在RS/GIS技术的支持下,以1970年1∶10万地形图、20世纪70年代末MSS遥感图像、80年代末TM 遥感图像和2000年左右ETM遥感图像为主要数据源,提取了4期湖泊数据,结合1965～2002年来温度、降水 和前人资料,分析了西藏地区湖泊分布及30年来湖泊变迁的时空差异特征。研究结果表明:西藏地区内陆湖泊 对全球和区域性气候变化有着敏感的响应,研究区内的湖泊在20世纪80年代末萎缩比较明显,2000年以来西 藏湖泊出现全面扩张的趋势。湖泊变迁的地区性差异主要体现在“藏北南部大湖区”的湖泊群和喀喇昆仑山地 区湖泊群持续扩张,藏北地区分布的中小型湖泊受温度升高影响最大,气候变化是湖泊面积变化的驱动因素,而 湖泊的地质、地理条件和补给方式等特征决定了湖泊的变迁类型和程度。

Dynamic Monitoring and Climatic Background of Lake Changes in Tibet Based on RS/GIS

Based on the 1∶ 100 000 topographic maps in 1970' s, remote sensing images of Landsat TM in 1990 and Landsat ETM in 2000,and the air temperature and precipitation datum from 1965 to 2002 in Tibet,this paper analyzes the distribution and variation of lakes in time and space. The results show that the change of inland lakes is sensitive to climate changes. Generally, the area of lakes in Tibet shrinked in 1980s, but increased since 2000. The regional differences in the changes of lakes indicate a continuous area-increasing lakes in the southern part of North Tibet and Galakunlun Mountain area. The driving force of area changing of lakes is fluctuant climate, but the other reasons, for example, geological or geographical conditions, riverhead supply mode, and so on,deter- mine the types and grades of change.