江苏沿海地区可承载城乡建设用地能力及匹配性评价

城乡建设用地是土地利用的重要类型,确定区域可承载城乡建设用地能力即承载规模和承载边界对土地利用开发具有重要的指导意义。研究从生态限制与适宜性的角度尝试确定城乡建设用地的承载能力,选择地形条件、地质条件、土壤条件、陆域生物多样性保护和水生态保护5个方面的指标要素作为城乡建设用地空间扩展的生态约束条件,基于GIS空间分析方法和“水桶效应”原理,对江苏沿海地区综合生态适宜性和城乡建设用地可承载性进行评价,制作了综合生态适宜性和可承载性格局分布图,确定了江苏沿海地区城乡建设用地承载阈值及其分布,统计了各县市区可承载城乡建设用地丰度,比照江苏沿海地区现状建设用地分布图与城乡建设用地可承载性分布图,开展了可承载与现状城乡建设用地匹配性评价,核算了城乡建设用地承载潜力,得到江苏沿海地区、南通市、盐城市和连云港市承载潜力分别为14.37%、15.29%、12.58%和17.07%,从而为江苏沿海地区城乡建设用地的优化配置和差异化管理决策提供依据。

Carrying Capability and Matching Evaluation of Urban and Rural Construction Land in the Coastal Areas of Jiangsu Province

Urban and rural construction land is one of the important land use types. Setting bearing capacity of urban and rural construction land, i.e. bearing scope and border is significant for guiding land development. Based on ecological suitability, five types of ecological security elements, including terrain conditions, geological conditions, soil conditions, land biodiversity conservation and water ecological protection, were selected as the ecological constraints for the spatial expansion of urban and rural construction land, and then the integrative ecological suitability and bearing capacity of urban and rural construction land in the coastal areas of Jiangsu Province was evaluated using the GIS spatial analysis tools based on the principle of buckets effect. The spatial distribution of ecological suitability and bearing patterns was mapped, the bearing thresholds were set, and the abundance of bearing capacity in each county and city was counted. According to current distribution of bearing capacity of construction land, the match between bearing capacity and current construction land was evaluated, and bearing potentiality was accounted. The results showed that the ratio of the area of construction land with carrying capacity to the total land area was 29.53% in the case of no harm to ecological security in the coastal areas of Jiangsu Province, however, the area percent of current urban and rural construction land was 15.16%, so there was still 14.37% bearing space of current urban and rural construction land. The ratios of the area urban and rural construction land with carrying capacity to the total land area were 32.12%, 25.28% and 35.41% in Nantong city, Yancheng city and Lianyungang city, respectively. Their area percents of current urban and rural construction land were 16.82%, 12.69% and 18.34%, respectively, so there were still big bearing space of urban and rural construction land for these cities. According to the spatial pattern of ecological suitability in the coastal areas of Jiangsu Province, the seven counties (or cities or districts) including Rugao City, Chongchuan District, Gangzha District, Nantong Economic and Technological Development District, Tinghu District, Xinpu District and Lianyun District have abundant resource for urban and rural construction land, then the nine counties (or cities or districts) including the Qidong City, Hai’an County, Tongzhou District, Funing County, Yandu District, Ganyu County, Donghai County, Guanyun County and Haizhou District are moderate in urban and rural construction land resource, and the left nine counties (or cities or districts) including Haimen City, Rudong County, Dongtai City, Dafeng City, Jianhu County, Sheyang County, Binhai County, Xiangshui County and Guannan County lack of urban and rural construction land resource. The results will benefit to the spatial optimization allocation of the urban and rural construction land and differentiated management.