重庆山地都市区1985-2010年土地利用变化地形特征分异研究

Research on the Differentiation of Land Use Terrain Feature from 1985 to 2010 in Chongqing Mountainous Metropolitan Area

随着城市化的不断推进,在低强度土地利用类型逐步向高强度土地利用类型转移的过程中,土地利用受地形因子的制约性越显突出。以重庆山地都市区为例,利用TM数据和DEM数据,综合研究分析1985—2010年间重庆都市区的各类用地在高程、坡度以及地形位不同地形因子中的分布变化过程。研究表明:重庆都市区各用地类型在不同地形因子等级下分异性特征显著,各地形因子等级中土地利用随时间变化的规律性特征明显。近25a来,重庆都市区高强度土地利用类型主要分布在500m高程以下的平地和400m高程以下的低缓坡,结构相对稳定;在500～1 200m的平地、400～600m的低缓坡以及500m以下的高缓坡区域内耕地、林地、建设用地、草地等土地利用类型空间竞争态势明显,人地矛盾突出,是协调人地关系的核心区域;重庆都市区内的陡坡、500m以上的高缓坡以及600m以上的低缓坡内的草地、林地面积减少,土地利用将对生态环境产生严重影响,应作为重庆都市区土地利用的重点监测对象。文章旨在为重庆都市区土地利用的合理规划提供参考。

Along with the shift of low-intensity land use type into high-intensity land use, the conditionality of land topography on land use is more and more outstanding in the process of urbanization. Chongqing Moun- tainous Metropolitan Area was taken as an example in this paper. Based on the data of DEM and annual TM of Chongqing Mountainous Metropolitan Area from 1985 to 2010, the change rule of distribution index of land use in different altitude, slope and terrain niche was comprehensively analyzed. The results indicated that the distribution index of different land utilization types in different terrain factors had significant differ- entiation characteristics. The change rule of land use in every terrain factor level had obvious regularity with time process. During the 6 years since 1985, the high strength utilization land was mainly concentrated in the flatland with the altitude lower than 500 m and low gentle slope with the altitude lower than 400 m. The structure of land use was always stable in these areas. The regions in flatland with altitude of 500-1 200 m, low gentle slope with the altitude of 400-600 m and high gentle slope with the altitude lower than 500 m be- cause of the obvious contradiction between human and land. Various types of land use showed a clear trend of competition in these areas. The phenomenon of the area reduction of grassland and woodland was happened in the high gentle slope with the altitude higher than 500 m, low gentle slope with the altitude higher than 600 m and the entire steep slope. These are key areas of land-use monitoring in Chongqing Mountainous Metropoli- tan Area because human will seriously affect the ecological environment through the land use in these regions. The results provide reference for the reasonable plan of land use in Chongqing Mountainous Metropolitan Area.