山地丘陵区耕地质量可提升潜力空间分布及保护分区——以重庆市江津区为例

Spatial distribution and protection zoning of cultivated land quality improvement potential in mountainous and hilly regions:A case study of Jiangjin District, Chongqing City

基于地貌尺度划定耕地保护区可为山地丘陵地区国土空间规划编制提供新的视角。本研究采用耕地质量提升潜力模型和空间自相关分析方法,探讨重庆市江津区耕地质量可提升潜力空间分布特征;在与耕地质量可改良因子限制程度相结合的基础上,根据耕地保护分区识别与强度诊断模型,划定不同地貌类型的耕地保护区。结果表明:研究区耕地质量可改良因子限制程度总体呈“南北高中间低”的带状分布形态;高限制区所占面积最大,占比34.78%。研究区耕地自然等可提升潜力指数呈现东南向西北降低的分布趋势“,随机”型分布较多,占比41.71%;耕地利用等可提升潜力指数呈“北高南低”的分布趋势“,高-高”型“、低-低”型和“随机”型三者分布占比相当。浅丘平坝区应以重点保护为主,将其划为永久基本农田保护范围;中丘区应将一般保护与重点保护相结合,尽力避免非农建设的挤占;高丘区和山地区应将一般保护与限制保护相结合,通过退耕还林还草、农业结构调整促进生态农业建设。将耕地质量提升潜力与耕地质量限制程度相耦合能够更加明确耕地近期重点保护的区域,同时从地貌尺度划定耕地保护区能够与耕地差异化保护的现实需求相适应,两者可为山地丘陵区耕地资源保护与可持续利用提供理论支撑。

This study demarcated the protection areas of cultivated land based on the landform scale, which provided a new perspective for territorial spatial planning in mountainous and hilly districts. The improvement potential model of cultivated land quality grade and spatial autocorrelation analysis were used to explore the spatial distribution characteristics of the improvement potential of cultivated land quality in Jiangjin District, Chongqing City. According to the cultivated land protection zoning identification and intensity diagnosis model,farmland protection areas with different physiognomy types were obtained, combined with the limited degree of quality improvable factors of farmland. The results showed that the limiting degree of cultivated land quality′ s improvable factors were zonal distribution with“high in the north and south but low in the middle”and highly limited areas accounted for 34.78%, which was the largest part of the study area. The distribution of improvement potential index of cultivated land nature quality grade decreased from southeast to northwest;most of study areas were“random”type distribution, accounting for 41.47%. The distribution of improvement potential index of cultivated land utilization quality grade showed“high in the north but low in the south”, and the area ratio of“high-high”,“low-low”, and“random”type were the same. Cultivated land should be protected mainly in hillock and zero-slope districts, which are demarcated into permanent prime farmland protection areas. General and key protection should be combined for cultivated land in low-maintenance and hill districts to avoid crowding out of non-agricultural construction. General and restricted protection should be combined for cultivated land in high mountain and hill districts, which can be strengthened by returning farmland to forest or grassland and adjusting the agricultural structure. Coupling the promotion potential index of the cultivated land quality grade with a limited degree of cultivated land quality can clarify the key areas of cultivated land protection in the near future. Cultivated land protection zones demarcated from the geomorphic scale can meet the actual needs of differentiated protection of cultivated land. Both can provide theoretical support for the protection and sustainable utilization of cultivated land resources in mountain and hilly districts.