伊犁河跨界流域土地利用变化特征分析

土地利用变化引发的水资源问题往往成为跨界流域各国矛盾的焦点，如何充分考虑跨界流域的特殊性和复杂性，对土地利用变化研究提出了新的要求。本文利用 MODIS产品提取了伊犁河流域2001-2009年土地利用数据，划分流域的产水/耗水区，结合流域跨界特点分析其土地利用变化特征。研究时段内，伊犁河流域土地利用以农田和天然植被为主，农田总面积有所下降，天然植被面积基本稳定。其中上中游产水区林地出现萎缩，草地面积增幅较大；中游水库耗水区内农田大幅度转化为天然植被；下游三角洲耗水区土地利用开发受限，人类干预程度下降。产流区内中国农田面积相对境外持续增加，而天然植被面积相对境外则持续缩小。受制度影响，哈萨克斯坦境内土地利用变化波动明显，中国境内土地利用变化幅度相对稳定。

Land Use/cover Change Analysis in Transboundary Ili River Basin

Water resources problems caused by land use/cover change often become the focus of conflicts among countries in transboundary basin, and taking the particularity and complexity of transboundary river basins into account in the land use/cover changes anal-ysis is proposed. In this study, the land use/cover data from 2001 to 2009 in Ili River basin was extracted on the basis of MODIS products, then regions divided into the water resources production and consumption, and characteristics of land use/cover change were analyzed. The results showed that farmland and natural vegetation accounted for the largest areal proportion in the Ili River basin, the area of farmland declined during the study period while the natural vegetation stays considerably stable. In the upper and mid-dle reaches water production region, the woodland shrank while the grassland expanded;in the midstream reservoir water consumption area, farmland was dramatically transformed the natural vegetation, and the large area of reservoir lead to seriously invalid water sur-face loss; in the delta, the area of land use/cover that most closely associated with hu-man activities were all decreased which means the decline in the degree of human inter-vention. In the runoff generation region upstream, the difference between farmland in and out of China continued to increase, while the natural vegetation area suffered the inverse relationship. Due to the fluctuations of institutional, land use/cover in Kazakhstan fluctuat-ed more obviously while the land use/cover in China changed relatively stable.