近30年来长江源区土地覆被变化特征分析  

Characteristics of Land Cover Change in Headwaters of the Yangtze River over the Past 30 Years

作　　者：吴丹[1,2] 邵全琴[1] 

机构地区：[1]中国科学院地理科学与资源研究所,北京100101 [2]中国科学院大学,北京100049

出　　处：《地球信息科学学报》2014年第1期61-69,共9页Journal of Geo-information Science

基　　金：国家重点基础研究发展计划"973"项目(2009CB421100);国家重点基础研究发展计划"973"项目(2010CB950900);全国生态环境十年(2000-2010年)变化遥感调查与评估项目(STSN-14-00)

摘　　要：长江源区是我国重要的水源涵养地。本文利用20世纪70年代中后期、90年代初期、2004年和2008年共4期土地覆被数据,通过土地覆被转类途径与幅度、土地覆被状况指数和土地覆被转类指数,分析评价了长江源区近30年来土地覆被与生态状况的时空变化特征。结果表明:草地是长江源区主要的土地覆被类型,2008年草地面积占该区总面积的66.93%。在70年代中后期-90年代初期、90年代初期-2004年和2004-2008年的3个时段内,土地覆被状况指数变化率分别为-0.15、-0.24和0.01;土地覆被转类指数分别为-0.20、-0.66和0.08。近30年来,长江源区土地覆被和生态状况总体经历了变差-显著变差-略有好转的过程。2004-2008年,长江源区年平均温度比前期(70年代中后期-2004年)升高了0.57℃,年平均降水量比前期增加了17.63mm。区域气候变化有助于自然生态系统的恢复。后期生态保护与建设工程的实施,对植被恢复产生了一定的积极作用。The water conservation service of headwaters of the Yangtze River is very important for ecological se-curity in China. It is generally acknowledged that the source of the Yangtze River includes the Tuotuohe headwa-ter, Dangqu headwater and Chumaerhe headwater. Based on the land cover dataset of middle and late 1970s, ear-ly 1990s, 2004 and 2008, this paper analyzed temporal and spatial change characteristics of land cover and eco-logical condition in headwaters of the Yangtze River over the past 30 years, using the method of direction and ex- tent of land cover change, land cover condition index and land cover change index. The results showed that grass-land was the main land cover type in this region in 2008, with a ratio of 66.93% in area. The glaciers were main-ly distributed in Tuotuohe headwater, while the marshland was mainly distributed in Dangqu headwater. The change rate of land cover condition index during 1970s-1990s, 1990s-2004 and 2004-2008 was-0.15,-0.24 and 0.01, respectively; while the land cover change index of three periods was -0.20, -0.66 and 0.08, respective- ly. The land cover and ecological condition of the study area had overall experienced a process of degenerated-obviously degenerated-slightly meliorated since 1970s. The mean annual temperature and precipitation from 2004 to 2008 was 0.57℃ and 17.63mm higher than that from 1970s to 2004. Regional climate change over re-cent years was helpful for natural ecosystem recovery. In addition, implementation of the ecological protection and construction project since 2004 also had certain positive effects on vegetation restoration.

关 键 词：土地覆被 状况指数 转类指数 长江源区 

分 类 号：F301[经济管理—产业经济]