清水江流域土地利用及其变化的地形特征分异研究

Research on the Topographic Differentiation of Land Use and Land Use Change in Qingshuijiang Watershed

以清水江流域为研究区，综合应用3S技术，基于遥感影像数据，提取研究区2002年及2013年土地利用现状图；基于研究区DEM数据，提取流域高程、坡度、坡向及坡位数据；通过土地利用与地形的叠加分析，获得属性数据库，采用分布指数分析了清水江流域土地利用及其变化的地形特征分异。研究结果表明：清水江流域各地类在不同地形等级下分布特征明显；在2002-2013年间，各地形因子对土地利用变化的影响程度不同，高程对土地利用变化影响较大，除个别地类外，坡度、坡向及坡位对土地利用变化均有一定的影响；流域内推进“退耕还林还草”工程有待延续及加强；在高程为750～1500m、坡度范围为〈15°、缓坡区域各地类竞争激烈，人地矛盾突出，是协调人地关系的核心区域，合理配置该区域土地利用具有深远意义；流域内未利用地分布广泛，对未利用地的合理开发利用有利于缓解清水江流域的人地矛盾；流域内对水的开发利用强烈的影响水域的地形特征，同时对其他地类也造成了不同程度的影响，由此可能导致的生态环境问题不容忽视。

Taking Qingshuijiang watershed as the study area, with the comprehensive application of 3S technology, basing on remote sensing images, the paper calculated the present land use map in 2002 and 2013; with the extracted elevation, slope, aspect, and slope position on DEM, the paper made them overlay to the land use variation map to get the attribute database. And then using the distribution index, the paper analyzes the topographic differentiation of land use and land use variation in Qingshuijiang Watershed. The research results showed： There are significant characteristics on the distribution of each land use type at different terrain levels; During 2002 to 2013, different topographic factors have various degree impact of land use change, while the elevation makes obvious impact on land use variation, in addition to individually land use types, slope, aspect and slope position have some significant affect on the land use change ; In the watershed, to continue and strengthen the ＂Grain for Green Project＂ is needed; At elevation in 750-1500 m, slope〈 15~, slope position in gentle slope, there is intense competition in land use types, and the relationships between human and land is obviously contradictory, and it is the core area to coordinate man-land relationship, and reasonable allocation of land use in the region has far-reaching significance; Unused land is widely distributed in the basin, rational development and utilization of unused land will help ease the contradiction between people and land in Qingshuijiang basin; it can＇t be ignored that the exploitation of water strongly influenced topographic features of waters in the basin, and that caused different degrees of influence of the other land use types, which may lead to environmental problems.