皖江平原冬闲田油菜扩种空间潜力及影响因子研究

RESEARCH ON THE SPATIAL POTENTIAL AND INFLUENCING FACTORS OF WINTER FALLOW FIELDS' EXPANSION FOR RAPESEED CULTIVATION IN THE WANJIANG PLAIN

关键词:  冬闲田  冬油菜  MaxEnt模型  空间潜力  皖江平原

Key words:  winter fallow fields  winter rapeseed  MaxEnt model  spatial potential  Wanjiang Plain

摘要:

目的 长江流域开发冬闲田扩种油菜是实施油料产能提升的重大举措，对保障国家食用油供给安全具有重大意义。然而，在具备冬闲田扩种油菜潜能的皖江平原，冬闲田和油菜的空间布局尚不明晰，如何在冬闲田扩种油菜还有待深入研究。方法 文章基于Sentinel-2影像，利用随机森林法提取冬闲田与油菜空间分布数据，并分析其空间格局特征；同时，选取影响油菜种植分布的高程、坡度、水系、道路、居民点和土壤类型等因子，借助MaxEnt模型模拟皖江平原地区冬闲田扩种油菜适宜分布空间，并结合冬闲田进行油菜扩种分区。结果 （1） 皖江平原约有冬闲田7 422.02 km²，冬季耕地闲置率为64.63%，油菜种植约为495.76 km²，种植率仅为4.32%，冬闲田主要分布在无为市、芜湖市南陵县等地区，整体主要分布于大别山沿线县区，油菜种植整体主要分布在长江沿线的县区；（2） 影响油菜种植分布的因子主要是坡度与高程，贡献率达到64.5%；皖江平原约有6 618.41 km²的耕地适宜和较适宜种植油菜，占耕地面积的57.64%，主要分布在长江沿线的县区，42.36%的耕地不适宜种植油菜，主要分布在长江沿线以北的县区；（3）在冬闲田扩种油菜适宜和较适宜的面积分别为616.38 km²和3 247.85 km²，占冬闲田面积的8.30%和43.77%，主要分布在安庆市望江县、芜湖市南陵县、鸠江区、马鞍山市和县和含山县等主要沿江沿湖地区。结论 皖江平原冬闲田扩种油菜潜力较大，52.06%的冬闲田适宜扩种油菜，年生产油菜约76.5万t。

Abstract:

The development of winter fallow fields for rapeseed expansion in the Yangtze River Basin is a significant initiative to enhance oilseed production capacity, crucial for ensuring national edible oil supply security. However, in the Wanjiang Plain, which has the potential for expanding rapeseed cultivation in winter fallow fields, the spatial layout of these fields and winter rapeseed is not clear. In this study, based on Sentinel-2 imagery, the random forest method was utilized to extract spatial distribution data for winter fallow fields and winter rapeseed, and their spatial pattern characteristics were analyzed. The factors influencing winter rapeseed distribution, such as elevation, slope, water systems, roads, residential areas, and soil types were selected. The MaxEnt model was employed to simulate the suitable areas for winter rapeseed expansion in the Wanjiang Plain, combining winter idle fallow for zoning. Results showed that: (1) There were approximately 7 422.02 km² of winter fallow fields in the Wanjiang Plain, with a winter fallow rate of 64.63%. The area for winter rapeseed cultivation was about 495.76 km², with a planting rate of only 4.32%. Winter fallow fields were mainly distributed in areas like Wuwei city and Nanling county in Wuhu city, primarily along the Dabie Mountains. Winter rapeseed cultivation was predominantly in counties and cities along the Yangtze River. (2) Factors affecting rapeseed planting distribution were primarily elevation and slope, contributing to 64.5%. Approximately 6 618.41 km² of cultivated land in the Wanjiang Plain was suitable and moderately suitable for winter rapeseed cultivation, accounting for 57.64% of the total cultivated land area, mainly distributed in counties and cities along the Yangtze River, while 42.36% of the cultivated land was unsuitable, mainly in counties and cities north of the Yangtze River. (3) The suitable and moderately suitable areas for winter rapeseed expansion in winter fallow fields were 616.38 km² and 3 247.85 km², respectively, constituting 8.30% and 43.77% of the winter fallow fields area, which were mainly distributed in regions along the Yangtze River and lakes. Therefore, there is great potential for expanding winter rapeseed in the winter fallow fields in Wanjiang Plain, with at least 52.06% of winter fallow fields suitable for expanding rapeseed planting, and the annual production of rapeseed is about 7.65 × 10⁵ t.