新疆和田河流域土地利用及其生态服务价值变化

Study on Land Use Change and Its Effect on Ecological Service Value in the Hotan River Basin,Xinjiang

土地利用结构决定土地生态系统服务价值,生态服务价值也反映了土地利用结构的生态优劣。基于遥感和G IS技术及数理统计学方法,利用1990年、1999年、2002年和2005年遥感影像解译得到的4期土地利用数据,对和田河流域1990-2005年土地利用变化进行定量分析,估算出研究区15年间的生态服务价值变化量。结果表明:①耕地、林地和城乡建设用地面积增加,草地、水域和未利用地面积减少;研究区土地利用处于发展时期,土地利用综合程度日益提高;优势度没有发生明显的变化,未利用地一直最高。②土地生态系统服务价值量有所增加,土地利用总体生态效应趋良。但环境也存在着局部恶化,主要表现在上游山地生态系统冰川退缩、天然植被退化;中游绿洲生态系统耕地扩张迅速,土壤盐渍化,人工渠、水库增加显著;下游荒漠生态系统植被退化,水资源严重不足,土地沙漠化。

It is of significance to study land use change and its effect on ecosystem service value. Ecosystem service value is affected by land use structure, and ecological service value reflects the ecological situation of land use structure. In this paper, the land use change in the Hotan River Basin in Xinjiang during the period from 1990 to 2005 is quantitatively analyzed using the land use data interpreted from the RS images in 1990, 1999, 2002 and 2005 based on RS and GIS means and＇ statistical approach. On which the ecological service values in the study area in recent 15 years are estimated. The results are as follows： （ 1 ） At the 15-year scale, the areas of cultivated land, woodland and building land in the Hotan River Basin were enlarged, while the areas of steppe, unused land and waters were reduced; land use in the study area was at developing stage, and the comprehensive level of land use was gradually increased; the dominance degree change was not obvious, and the dominance degree of unused land was the highest all along; （2） The ecosystem service value was increased to some extent and the ecological effect was tended towards a virtuous circle through land use change in the Hotan River Basin. However, the ecological environment was deteriorated in some areas, such as the shrinkage of modern glaciers and the degeneration of natural vegetation in mountainous region in the upper reaches, enlargement of cultivated land, soil salinization and obvious increase of irrigation canals and reservoirs in the middle reaches, and degeneration of natural vegetation, serious shortage of water resources and land desertification in the lower reaches.