基于“双评价”的城镇开发边界划定技术——以湘潭县中心城区为例

构建“生态—农业—建设综合统筹”的城镇开发边界划定技术模型,即按“短板理论”计算空间约束下的县域建设开发建议规模,按指标权重计算综合得分进行国土空间开发适宜性评价,按生态优先、耕地保护优先原则确定地块规划功能,结合城镇建设现状、社会经济发展和城乡协调发展等因素划定城镇开发边界。以湘潭县中心城区为例进行实证,划定城镇开发边界4500 hm²。结果表明：与湘潭县土地利用总体规划规模边界、城市总体规划中心城区空间增长边界相比,本次划定的城镇开发边界中生态极重要或极敏感区域由3.49%、12.46%降为0,新增建设用地占用耕地的比例由53.26%、50.94%降低到21.02%,新增建设用地年均增速相比降低了45.65%。该技术模型对优化国土空间开发利用保护布局,促进绿色发展、高质量发展起到了积极作用。

Demarcation technology of urban development boundary based on evaluation of carrying capacity of resources environment and suitability of land space development: A case study of the central city of Xiangtan county

To construct the model of "Ecology-Agriculture-Construction Comprehensive Planning" for delimitation techniques of urban development boundary, this paper calculates the proposed scale of county construction and development under spatial constraints based on "Short Board Theory", evaluates the suitability of land space development by calculating the comprehensive score according to the index weight, determines the land plot planning function and identifies construction priority areas in accordance with the principle of ecological priority and cultivated land protection priority. Then on these bases, the urban development boundary shall be delimited according to the urban construction conditions, laws and regulations, social and economic development, urban and rural coordinated development and other factors, with the priority areas as the base map and the scale of urban construction land as the basis. Through the empirical research on the central area of Xiangtan county, the urban development boundary of 4500 hectares has been determined. Compared with the scale boundary of the land-use master plan and the spatial growth boundary of the central district of the urban master plan, the technical model fully considers the restrictive effects of ecological environment, land resources, water resources, natural disasters and other factors on construction and development. The ecologically important or sensitive areas in the urban development boundary have been reduced from 3.49%, 12.46% to 0. The proportion of cultivated land occupied by new construction has been reduced from 53.26%, 50.94% to 21.02%, without occupying permanent basic farmland and ecological forests. The average annual growth rate of new construction land has been reduced by 45.65%, which is divided into or radiated into the concentrated area of village distribution. There are some problems in the traditional methods, such as determining the scale of construction land in the light of the development needs without considering the constraints of resources and environment on urban development, and ignoring the multiple suitability of land, etc. The research result shows that the technical model proposed in this paper makes up for the above shortcomings, so as to realize the priority of ecology and farmland protection, and promote conservation and intensive land use and urban-rural coordinated development. In addition, it can play a positive role in optimizing the layout of land space development, utilization and protection, and boosting green and high-quality development.