基于综合生产能力核算的河北省耕地重点保护区划定

耕地保护的实质是要保护耕地的综合生产能力，按耕地生产能力重新划定耕地的保护等级是保护耕地资源安全，最终实现耕地综合生产能力稳定的根本举措。基于农用地分等成果，通过抽样补充调查，依据自然等指数与理论生产能力抽样样点构建耕地远景潜在生产能力的核算模型，应用利用等指数与现实生产能力抽样样点的实际调查数据构建耕地现实生产能力的核算模型。在此基础上，采用综合生产力优势指数和生产规模优势指数对耕地生产能力进行分析，从远景潜在生产能力、现实生产能力、耕地投入水平和产出水平4个方面构建耕地重点保护区划分指标体系并将河北省耕地划分为4个保护等级，其中第一级别为国家级耕地保护区，面积为2.02×106 hm2，占耕地总面积的32.1%；第二级别为省级耕地保护区，耕地总面积为2.98×106 hm2；第三级别为市级耕地保护区，占河北省耕地总面积的30.1%；第四级别占河北省耕地总面积的9.7%。通过耕地保护区域的划分，明确不同主体的保护职责，并认真研究与完善耕地保护政策，这对于稳定农业生产、确保粮食安全具有重要的现实意义。

Division of key cultivated land regions based on calculation of comprehensive productivity in Hebei province

The essential of protecting the cultivated land was to protect the comprehensive production capacity. It was the fundamental measure for ensuring resources security and sustaining productivity stability of the cultivated land to divide the cultivated land into different ranks according to the production capacity. The theoretical production capacity of cultivated land was obtained from the linear regression model which was established with the relationship of the natural quality ranks and the standard crop yield per unit from theoretical sampling investigation data on the basis of agricultural land classification. And the practical production capacity of cultivated land was obtained from the linear regression model established with the relationship of the land use quality ranks and the standard crop yield per unit from practical sampling investigation data. Then the scale advantage index and the aggregated advantage index of cultivated land were put forward to analyze the spatial distribution pattern of comprehensive productivity. Combing with the future potential productivity, current productivity and the input and output status, cultivated land in Hebei province was divided into four protective classes. The first class was the state-level protection region. The area was 2.02×106 hm2 which accounted for 32.1% of the total area. The second class was the provincial-level protection region and the area was 2.98×106 hm2. The third-level protection region was the municipal-level protection region which accounted for 30.1% of the total cultivated land in Hebei province. The rest was classified as the fourth-level which accounted for 9.7% of the total area. By the division of protected regions and definition of the protective duties of different subjects, it was of great realistic meanings to stabilize agricultural production and to ensure food security.