CAJ | 학술논문

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。
장강원구시아국중요적수원함양지。본문이용20세기70년대중후기、90년대초기、2004년화2008년공4기토지복피수거，통과토지복피전류도경여폭도、토지복피상황지수화토지복피전류지수，분석평개료장강원구근30년래토지복피여생태상황적시공변화특정。결과표명：초지시장강원구주요적토지복피류형，2008년초지면적점해구총면적적66.93%。재70년대중후기-90년대초기、90년대초기-2004년화2004-2008년적3개시단내，토지복피상황지수변화솔분별위-0.15、-0.24화0.01；토지복피전류지수분별위-0.20、-0.66화0.08。근30년래，장강원구토지복피화생태상황총체경력료변차-현저변차-략유호전적과정。2004-2008년，장강원구년평균온도비전기（70년대중후기-2004년）승고료0.57℃，년평균강수량비전기증가료17.63mm。구역기후변화유조우자연생태계통적회복。후기생태보호여건설공정적실시，대식피회복산생료일정적적겁작용。
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.