山地城市边缘土地利用格局与变化的地形梯度分布特征分析——以重庆市巴南区为例

地形作为重要的自然基底因子，在很大程度上影响土地利用变化与空间格局形成。以重庆市巴南区为例，借助GIS和RS手段，利用Landsat TM遥感数据和DEM数据，采用地形位指数、分布指数和土地利用程度综合指数等计算方法，对巴南区2000、2010和2015年土地利用格局与变化的地形梯度分布特征进行了分析，探讨了土地利用格局与变化和地形梯度的相互关系，以期为相似地形条件下的山地城市边缘区的人地关系研究提供支撑或参考。研究结果表明：（1）巴南区土地以中、高级地形位为主，海拔200 m以下，坡度8°以下的土地资源较为匮乏；（2）研究期内，中、低级地形位区间内大量耕地转变为建设用地，土地分布结构变化导致二者的分布优势区间均向更高级地形位区间转移；（3）土地利用程度综合指数曲线呈倒“V”型，波峰逐渐向中级地形位区间移动，可以印证在研究期内巴南区低丘缓坡区域内土地利用强度逐渐提升。

Distribution Characteristic on Terrain Gradient of Land Use Pattern and Change in the Fringe of Mountainous Cities: A Case Study of Banan District in Chongqing

As an important natural factor,terrain affects land use change and the formation of land use pattern remarkably.We analyzed the terrain gradient characteristic of land use change and land use pattern of Banan District,Chongqing in 2000,2010 and 2015 by using terrain niche index,distribution index and land use degree composite index.GIS(Geographic Information System),Landsat TM images and DEM images were used in the study.We explored the relationship between land use change and land use pattern and the terrain gradient,in order to provide reference to the studies on man-land relationship in the fringe of mountainous cities with rapid urbanization and industrialization.The results showed that:(1) land resources of Banan District mainly distributes in the medium and high level of terrain niche,while land in the low level,the most suitable terrain for human production and living (i.e.the land located at the attitude of 200m below and the slope of 8° below),is relatively scarce;(2) during the study period,amounts of cultivated land has been changed to construction land in the low and medium level of terrain niche.As a result,the dominant distribution extent of both cultivated land and construction land has shifted into the higher level of terrain niche due to the land distribution structure change;(3) the land use degree composite index of Banan District showed as an inverted Ⅴ curve,in which the peak approached to the medium level of terrain niche.It proved that the land use intensity in the hillside area has been increased gradually.