鄂西北山区土地利用的地形梯度效应与空间结构特征

地形因素在一定程度上影响着土地利用变化,对区域土地利用格局与空间结构特征有着重要影响。该文以鄂西北山区房县为研究对象,利用DEM提取高程和坡度信息,并生成地形位指数,借助GIS的空间分析功能,采用地形位指数、分布指数和土地利用强度综合指数,系统分析房县土地利用的地形梯度效应;在此基础上,应用分形理论探讨其土地利用的空间结构特征。结果表明:(1)房县各土地利用类型的空间分布具有明显的地形梯度特征,高程、坡度及地形位对房县土地利用格局的形成有着重要影响;(2)水域、交通用地、居民点及工矿用地、耕地的优势分布区间集中在低地形位区间,园地、草地和未利用地的优势分布区间集中在中地形位区间,林地的优势分布区间集中在高地形位区间;(3)房县土地利用强度综合指数随着地形位指数的增加逐渐降低;(4)房县各土地利用类型分布具有明显的分形特征,分维数介于1. 275 3～1. 759 3之间,各类用地的稳定性大小依次为:水域居民点及工矿用地园地林地耕地草地交通用地未利用地。研究结果可为该地区土地利用总体规划及土地资源优化配置提供科学的决策依据。

Terrain Gradient Effect and Spatial Structure Characteristics of Land Use in Mountain Areas of Northwestern Hubei Province

Topographic factors affect land use changes to a certain extent and have an important influence on regional land use patterns and spatial structure characteristics. The study area of this study is Fang County in the Northwestern Hubei Province. We used DEM to extract elevation and slope information, and generated the topographic index. With the help of the spatial analysis function of GIS, we systematically analyzed the land use terrain gradient effect of Fang County by using terrain index, distribution index and land use intensity index. Subsequently, we explored the land use spatial structure characteristics of Fang County using the fractal theory. The results showed that: (1) The spatial distribution of land use types in Fang County had obvious topographic gradient characteristics. Height, slope and topography had an important influence on the formation of land use patterns in Fang County. (2) Waterbody, transportation land, residential area and industrial and mining land, and arable land were mainly distributed in area with low terrain niche index. Garden land, grassland, and unused land were mainly distributed in area with medium terrain niche index, while forest land were mainly distributed in high terrain niche index area. (3) The comprehensive index of land use intensity in Fang County decreased gradually with the increase of topographic index. (4) The distribution of land use types in Fang County had obvious fractal characteristics, and the fractal dimension was between 1.275 3-1.759 3. The orders of stability of all types of land were: waterbody, residential area and industrial and mining land, garden land, forest land, arable land, grass land, transportation land, unused land. The results of this study can provide scientific supports for decision-making of the overall land use planning and land resource allocation in this region.