基于GIS的南方丘陵生态脆弱区土地利用适宜性研究——以衡阳盆地为例

Evaluation of Land Use Suitability of Hilly Area in Southern China Based on GIS:A Case Study in the Hengyang Basin

选择了土壤、气候、地形、水文和交通5类11个指标,建立了适用于南方丘陵区的土地适宜性评价指标体系;采用专家打分和层次分析法确定指标权重,并应用GIS技术建立了衡阳盆地的土地适宜性评价模型,对衡阳盆地耕地、林地和建设用地的土地利用适宜性进行了评价。结果表明:耕地适宜性以临界适宜性和一般适宜性为主,耕地不适宜区面积占研究区总面积的49.63%,主要分布在山区;建设用地高度适宜区面积占研究区总面积的5.32%,建设用地不适宜区域分布和数量与耕地不适宜区域分布和数量大致相当;林地适宜性整体较高。通过对比分析评价结果和基于TM数据提取的土地利用现状发现:现有耕地的适宜性以临界适宜和一般适宜类型为主,不适宜区域占耕地总面积的10.56%,主要分布在衡南县东部和西部以及衡阳县南部区域;现有建设用地整体适宜性较高,且分布集中,主要位于衡阳市区。据此提出衡阳盆地土地资源可持续发展对策。

The Hengyang Basin locates in the vulnerable ecological area in Southern China, because of the irrational human activities,soil erosion and red desertification are serious in the area. In this paper, Hengyang Basin is taken as the study area, five types of factors such as soil, climate, topography, hydrology and traffic, including 11 indexes are selected to build index system of land use suitability evaluation that is applicable to the study area, taking advantage of expert scoring and AHP methods to calculate the weight of indexes and using GIS GRID platform to build evaluation model, land use suitability of 3 land use type including arable field,construction land and woodland in Hengyang Basin are evaluated. The result shows： 1） The arable field suitability is mainly to critically suitable and normally suitable,the proportion of unsuitable areas to total area of study area is 49.63% ,and mainly locate in hiller area. 2） The proportion of high building land suitability to total area is 5.32% ,and the unsuitable building land and arable land regions almost share the same distribution. 3） The woodland suitability of study area is high and the area proportion of normal suitability and high suitability to total area is 94.17%. Some conclusions can be drawn by comparing the evaluation result to land use which is obtained from TM images, the arable land use is mainly to critical suitability and normal suitability, and the proportion of unsuitable area to total arable land is 10.560% and the unsuitable regions mainly lo cate in the eastern and western Hengnan County and southern Hengyang County, The suitability of building land is high and has concentrated distribution,and it mostly locates in Hengyang urban area.