基于地形梯度的岩溶槽谷区土地利用空间格局分析

揭示当前多因素驱动机制下岩溶槽谷区典型地貌单元在地形梯度上土地利用分布的一般规律与差异性特征具有重要意义。以2017年landsat TM高清影像和30 m×30 m DEM（Digital Elevation Model）为数据源，并结合实地调查，通过地形位分布指数、土地利用多样性指数、土地利用程度指数及土地利用相对合理性指数指标计算，探讨岩溶槽谷区地形梯度的土地利用类型空间分布共同特征与差异。结果表明：（1）岩溶槽谷区土地利用类型呈现山坡（高地形位）-槽坝（低地形位）两种分布格局特色存在，且土地利用类型在地形梯度上主要以低、中、高3种地形位组合模式；（2）土地利用类型在地形梯度上呈现梯度效应，表现出各自分布特征与差异；（3）岩溶槽谷区土地利用多样性、土地利用程度和土地利用合理性在地形梯度上分布格局既存在一些共同性特征，又存在各自差异性；（4）地形梯度土地利用特征差异性是受自然因素、社会经济因素、政策因素共同作用的结果。

Analysis of spatial pattern of land use based on terrain gradient in karst trough valley area

It is of great importance to identify the general laws and the spatial distribution characteristics of land use in a typical topography unit of karst valley area on terrain gradients influenced by various factors and mechanisms. This study, based on the high-resolution images of 2017 as the data source combined with field survey to verify the images, we calculated the terrain niche distribution index, land use diversity index, land use intensity index, and land use relative rationality index to explore the similarity and differences in the spatial distribution of land use types on terrain gradient in a karst trough valley area of Guizhou province. The results were as follows:(1) Land use type in the karst trough valley area is characterized by two distribution patterns, i.e., hillside (high terrain niche)-trough basin (low terrain niche). However, land use types on terrain gradients are mainly composed of low, middle, and high terrain niche combination models; (2) The land use type presents gradient effects on terrain gradients; it shows individual distribution characteristics and differences; (3) In the karst trough valley area, the distribution pattern of land use diversity, land use degree, and land use rationality on terrain gradients have some common features and some individual differences; (4) The land use characteristics on the terrain gradient are the result of natural, socio-economic, and policy factors.