基于地形梯度的贵州省土地利用时空变化分析

Spatio-temporal Patterns of Land Use Change in Guizhou Province Based on Terrain Gradient

【目的】探讨贵州省不同地形梯度上的土地利用变化特点。【方法】采用遥感解译和GIS统计分析相结合的方法,从高程、坡度、地形起伏度、地形位指数视角,分析了1990-2010年贵州省土地利用变化的地形梯度特征。【结果】研究期间贵州省土地利用类型分布表现出明显的梯度性。在坡度、地形起伏度和地形位梯度上,耕地、建设用地和水域主要分布于低梯度带。林地、草地和未利用地集中于高梯度带。在高程梯度带上,高海拔梯度带是耕地、草地和未利用地的优势区,低海拔梯度带是建设用地、水域和林地的优势区。1990-2010年各地形梯度带的耕地和未利用地面积降低,而林地、草地、建设用地和水域面积增加。主要表现为大量耕地和未利用地转为林地和建设用地。其中,耕地、草地、林地和未利用变化集中于中等及以下梯度带。建设用地和水域变化主要分布于中等高程带以及其他低地形梯度带。【结论】研究区土地利用变化地形梯度差异突出。自然条件,社会经济因素以及退耕还林还草政策是其主导因素。

[Objective]The aim of the study was to explore the characteristics of land use change in different terrain gradients.[Method]In this study,a method combining remote sensing and GIS statistical analysis was used.The terrain gradient characteristics of land use change were analyzed according to elevation,slope,landform relief and terrain niche from 1990 to 2010.[Results]The distribution characteristic of land use from 1990 to 2010 in Guizhou had a significant effect of ter-rain gradient.Farmland,construction land and waters were mainly distributed in the low terrain gradient of slope,landform relief and terrain niche.Conversely,woodland,grassland and unused land were distributed in high terrain gradient.Farmland,grassland and unused land were in high elevation.However,woodland,construction land and waters were in the low elevation.The area of farmland and unused land decreased in each terrain gradient from 1990 to 2010 while the area of woodland,grassland,construction land and waters increased.The most obvious is the conversion from farmland and unused land to woodland and construction land.The change of farmland, grassland,woodland and unused land concentrated in the average or lower terrain gradient.The change of construction land and waters were mainly distributed in the average elevation or other lower terrain gradient.[Conclusion]There were obvious differences in terrain gradients of land use change as a resust of natural condition,socio-economic factor and reforestation policy.