运用DEM剖析土地利用类型的分布及时空变化--以北京延庆县为例

以北京延庆县为例，从土地利用类型分布频率的角度，结合地形因子分析区域土地利用类型分布及变化规律。由于坡向影响着日照时数和土壤水分的再分布，而这对农业用地和园地等土地利用类型来说具有研究意义，因此，在前人的综合海拔和坡度两个地形因子的分布指数的基础上，提出坡向分布指数，即分别从海拔、坡度和坡向三个角度，对延庆县1996年和2001年土地利用现状数据进行比较分析，得出其耕地、园地和林地三种土地利用类型的分布及变化规律：耕地主要集中分布于低的地形等级上，园地则趋于高地形等级方向发展，并且阴坡上的分布频率有所增加，林地分布变化不明显。作者认为，人为干扰因素对园地分布格局的变化起到了一定的作用，而对耕地和林地的作用不明显，这为该区未来发展规划提供了参考。

Analysis of the Land Use Spatiotemporal Variation Based on DEM --Beijing Yanqing County as an Example

The rules of distribution and variation of territorial land use have been one of the hotspots ever so long. They are analysised in this paper from the point of view of frequency combining terrain factors, taking Beijing Yanqing county as the example.Elevation and slope are two important factors of land resource,which are closely related to land use and determine the ways of land use to a certian extent.For slope aspect has effect on the redistribution of sunshine hours and soil moisture, which is important for cultivated land and garden plot,slope aspect distribution index is brought forward based on the distribution index including altitude and slope proposed by the former.Namely,the distribution index of altitude,slope and slope aspect are used here,which represent the frequency of distribution of land use.The land use data of Yanqing county in 1996 and 2001 from altitude, slope and slope aspect is ulilized for further analysis. Finally we conclude that the rules of distribution and variation of cultivated land, garden plot and woodland:cultivated land mainly distribute in the lower grades of terrain,while garden plot in the trend of higher grades of terrain with increase distribution frequency in shady hillside,woodland's change doesn't show clear.It is believed that artificial interference has effect more on the distribution variation of garden plot while little on cultivated land and woodland..