基于GIS的山区土地资源安全定量评价模型 ——以四川省凉山州为例

土地资源是制约山区资源环境承载力的关键因素,土地资源安全状况在一定程度上决定了山区的资源环境安全状况和社会经济发展水平。在分析山区土地资源安全影响因素的基础上,论文构建了以建设用地安全指数和粮食安全指数为基础的山区土地资源安全评价模型。该模型使用城镇化率作为建设用地安全指数的权重,以反映建设用地安全在区域土地资源安全中的重要性；使用非城镇化率作为粮食安全指数的权重,以反映农村土地安全状态在土地资源安全中的重要性。在GIS 软件支持下,利用该模型对四川省凉山州各县市的土地资源安全指数进行了评估计算,结果表明凉山州土地资源安全情况总体不容乐观,土地资源安全等级为安全和较安全的县市仅有3 个,占全州县市总数的县市总数的17.65%,国土面积的17.23%；而土地资源不安全与临界安全的县就有10 个,占全州县市总数的58.82%,国土面积的55.03%。土地资源安全主要受地形条件约束,地形起伏度每下降0.09,土地资源安全指数约上升0.97。同时,土地资源不安全区与贫困区具有高度叠加的特点,这表明土地资源是主导山区发展和山区资源环境安全的关键因素,提高山区土地生产潜力,节约集约利用土地是保障山区土地资源安全及资源环境安全的重要措施。

Land Resources Assessment Model for Mountainous Areas Based on GIS: A Case Study of Liangshan Yizu Autonomous Prefecture, Sichuan Province

Land resources are key factors of the resources & environment capability in mountainous areas. They determine socio-economic development and sustainable development in the mountainous areas. So, land resources security assessment is an important task in mountain areas development planning. In this paper, a new land resources security assessment model for mountainous areas is developed based on geographic information system and statistical data. Firstly, the paper analyses the import factors for land resources security in mountainous areas. Then, the construction land security index and the food security index were been given in this paper. In order to compute the land security index, a dynamic weight was promoted, which can be computed for urbanization. The weight of construction land security index is the ratio of urbanization, and the weight of food security index is the ratio of non-urbanization. Taking Liangshan Yizu Autonomous Prefecture of Sichuan Province of China as a study area, we used the model to compute the construction land security index, food security index and land resources security index. The results show that the safest and safer land resources in Liangshan cover 17.65% of the counties, or 17.23% of the total land area, but land resources in unsafety and critical safety covers 58.82% of the counties of Liangshan, or 55.03% of the total land area. The result also indicates that topography is the most important factor affecting land resources security in this region, and the unsafe land resources areas are consistent with very poor areas. To improve the land productive potential, economical and intensive utilization of land resources are important measures for sustainable development & resources and environment security in mountainous areas.