基于地形梯度的皖南地区土地利用分布特征

以安徽省皖南地区为例,利用GIS空间分析技术,通过计算高程、坡度和地形位指数等地形梯度上的土地利用分布指数,分析了3种地形梯度上不同土地利用类型的分布特征,探讨了该区土地利用分布特点与地形间的关系。结果表明:(1)研究区在高程0~600 m、坡度0~21°和地形位指数0~1.575 0区域内的面积占皖南地区总面积的93.10%、83.11%和93.89%,影响着该区的土地利用类型分布;(2)土地利用类型分布分层明显,耕地、水域和建设用地主要分布在海拔较低、坡度平缓和地形位指数较小的区域,相应的土地利用分布指数随地形梯度的增大而减少直至趋于0;林地、草地分布则与之相反;(3)依据土地利用和地形的关系,皖南地区土地利用格局趋于合理,但不合理的土地利用方式仍然存在,需要加强其土地利用的规划管理。

Distribution Characteristics of Land Use Types Under Different Terrain Index Gradients in Southern Anhui Province

The spatial distribution characteristics of land use types under different terrain index gradients as well as the relationship between land use distribution pattern and topographic factors were studied in southern Anhui through calculating land use distribution indexes corresponding to different elevation, slopes and terrain indexes based on GIS technique. The results showed that: 1) The areas at altitude of 0-600 m, slope 0-21°and terrain index 0-1.575 0 occupy 93.10%, 83.11% and 93.89% of the total study area, respectively, dominating the distribution of land use types. 2) The study area is mainly composed of cultivated land, forest land and grassland. The terrain distribution of land use types has obvious hierarchical characteristics, cultivated land, water and construction land are mainly distributed in low terrain gradient, while forest land and grassland are mainly distributed on higher terrain gradient. 3) According to the relationship between land use and terrain features, land use pattern in southern Anhui tends to be more reasonable, but unreasonable land use is still existed, thus planning and management of land use need to be strengthened.