农产品质量安全导向的耕地质量评价及在城市开发边界划定中的应用——以南通市为例

快速城镇化过程中,耕地面临日益严重的质量和数量安全问题,改进耕地质量评价方法并探索其在城市开发边界划定中的应用研究,对于耕地和农产品质量安全保护、“多规合一”的实施具有重要意义。通过融合农用地自然质量分等和多目标地球化学调查成果,重构耕地质量评价指标体系与集成方法,结合耕地质量与规划城镇用地的耦合分析,探索可占用耕地与城市开发边界识别路径,并以南通为例进行验证。研究表明：沿江地区土壤重金属含量较高,沿海地区土壤肥力较差,西部和北部地区土壤肥沃,耕地质量较好。沿江地区规划城镇用地和耕地质量空间匹配较好,可占耕地和开发边界范围较大,北部地区相反。耕地质量评价—耕地与规划城镇用地耦合—可占用耕地选择与边界框定的方法,可以为城市开发边界划定提供指引,但城市用地需求和耕地可占用规模确定是有待深入研究的问题。

Cultivated land quality evaluation oriented to the safety of agricultural products quality and its application in city development boundary's definition:A case study of Nantong city

During the process of urbanization, cultivated land is confronted with new environmental quality and quantity safety issues, so expanding the connotation of cultivated land quality, improving the methods of cultivated land evaluation and exploring its application in the definition of urban development boundary is beneficial to the implementation of the "multi plans in one" strategy and also affects the improvement of safety of agricultural products and quality of people's livelihood. Based on the classification of natural quality of agricultural land and the results of multi-target geochemical survey, with Nantong as an example for verification, this paper restructures the cultivated land quality evaluation methods, sets up the coupling analysis framework between cultivated land quality and planned urban land and explores ways to identify available cultivated land and urban development boundary. Studies have shown that the content of heavy metals in the soil in areas along the Yangtze River is high, the fertility of the soil is poor and the quality of cultivated land is not high in coastal areas and the quality of cultivated land is high in the western and northern parts of the study area. Contrary to the northern part, the areas along the Yangtze River have perfectly matched planned urban land and cultivated land quality distribution and a wide range of available cultivated land and development boundary. The method system composed of cultivated land quality evaluation, coupling of cultivated land and planned urban land and selection of available cultivated land and definition of boundary can support the definition of urban development boundary, but the determination of urban land demand and cultivated land scale needs further study.