基于GIS的秦岭山区聚落用地适宜性评价

利用自然地理、生态和社会经济方面共14个因子构建秦岭山区聚落建设用地适宜性评价指标体系,采用AHP法确定各评价因子的权重,在地理信息系统(GIS)和遥感(RS)技术支持下,利用适宜性评价模型定量评价聚落建设用地适宜性,将聚落建设用地适宜性分为五个等级,并结合已建设区进行空缺分析。结果表明:(1)秦岭山区最适宜聚落用地面积为3378.1 km2,占研究区总面积的5.87%,说明秦岭山区适宜聚落开发的土地相对较少。(2)最适宜聚落用地集中在秦岭北、南坡山麓和东部的山间河谷地带,山地型特征明显。(3)有9.15%已建成区分布在限制建设区内,存在生态安全风险。(4)可用适宜聚落建设用地为3192.27 km2,空间分布不平衡。研究结果可为该区域城镇体系布局与用地规模的核算提供科学依据。

Suitability analysis of mountain settlements in Qinling using a GIS system

Understanding the spatial characteristics of land suitable for settlement construction underlies urban master planning and subject planning and helps to alleviate the pressure of population growth and economic development in areas of limited land resources. The research community, however, has mainly focused on rapid urbanization areas such as regional metropolitan areas. This study used the multi-factors overlay comprehensive evaluation method to evaluate the spatial characteristics of land suitable for settlement construction. Specifically, we chose the Qinling mountains as a typical example, which are of vital importance in determining suitable land in mountainous areas where the carrying capacity of the environment is sensitive and weak. Using a geographic information system (GIS) and remote sensing technology, we revealed the spatial characteristics of settlement construction suitability, which utilized 14 indicators taken from natural geography, ecology and socio-economic data. We ascertained the weight of each indicator using an analytic hierarchy process method, and thereby determined the amount of land suitable for settlement construction in various counties. The main results were as follows: (1) Areas with different levels of suitability appeared to have significant differences. Most of the Qinling mountains are not suitable for settlement construction. The area of optimum land available for settlement construction in this region was 3378.1 km², accounting for 5.87% of the study area-a relatively small proportion of suitable land. (2) Land suitable for settlement construction in the Qinling mountains showed an obviously spatial heterogeneity: The most appropriate land was concentrated in North and South Piedmont and East Valley, which showed obvious mountainous features. (3) Results of gap analysis in the built-up area showed that 9.15% of built-up settlements were distributed in restricted construction regions, especially in counties such as Foping, Zhouzhi, Huxian, Taibai as well as Yangxian, which presented ecological safety risks. (4) There were 3192.27 km² of land suitable for settlement construction, distributed unequally in spatial terms. Most of these areas were distributed in counties such as Shangluo, Hangyin, Shanyang and Lueyang, and some other counties. In Foping, there was only 2 km² available for settlement construction. (5) In order to more effectively apply the results to urban system planning and biodiversity conservation in the Qinling mountains, we proposed the following recommendation: Consider both the actual location of the various towns and the results of the suitability evaluation for settlement construction when determining the future pattern of urban development. This study provides an insight into a suitability evaluation for settlement construction in a mountainous area. These findings provide scientific support for urban planning and for estimating the area of suitable land, while the research methods and reasoning used can help to achieve a win-win scenario between urbanization and biodiversity conservation.