镇域尺度的规模农地演变特征及其驱动机制研究——以重庆奉节县为例

Evolution Pattern and Driving Mechanism in Farmland of Scale on Town Level:A Case Study of Fengjie County in Chongqing,China

在土地利用逐步集约化以及乡村振兴战略背景下,厘清山区规模农地时空演变规律及其驱动机制,对于整合山区有限的农地资源,推动农业适度规模化经营意义重大。为揭示山区镇域尺度规模农地演变规律,本文基于重庆市奉节县典型山区乡镇2008年、2018年两期4类农地斑块数据,综合运用GIS空间分析技术和景观格局指数等方法对比分析草堂镇、康乐镇规模农地发展演变特征,并引入地理探测器模型进一步探讨规模农地演变的驱动因子。结果显示:传统型耕地数量呈下降态势,现代型果园数量均有所增长,现代型蔬菜、茶园数量比较稳定;传统型耕地分布热点区域缩减,现代型果园核密度最高值是2008年的2~3倍,各类型规模农地在镇级尺度分布呈聚集、均匀和随机3种模式,集聚特征空间尺度范围缩小;斑块特征上CA、NP、MNN三项指标变化最大,CA与NP呈正相关,最小平均最近距离MNN由传统型耕地变为现代型果园,现代型蔬菜斑块形状最为规整;距河流距离、距道路距离和农业人口密度等主导因子以及距河流距离∩高程、距道路距离∩农业人口密度等交互因子是推动规模农地演变的重要驱动力。本研究对于山区农地资源整治、规模农地发展以及转变农业发展模式具有借鉴意义。

In the context of gradual land-use intensification and rural revitalization strategy,clarifying the spatiotemporal evolution of farmland of scale(FS)in mountainous areas and its driving mechanism is of great significance for integrating limited mountainous agricultural land resources and promoting moderately large-scale agricultural operations.Based on four FS types of typical mountain towns in Fengjie County,Chongqing Municipality in 2008 and 2018,this paper compared and analyzed FS in Caotang and Kangle Town using GIS spatial analysis technology and landscape pattern index comprehensively to reveal the town-scale FS evolution in mountainous areas.Meanwhile,the Geo-detector model was introduced to explore the driving factors of FS evolution further.The results showed that the number of traditional cultivated land has declined,the number of modern orchards has increased,and the number of modern vegetables and tea gardens has been relatively stable.The distribution hotspots of traditional cultivated land have shrunk,and the highest kernel density value of modern orchards was 2~3 times than that in 2008.Overall,the distribution of various FS types at the town level howed three patterns of aggregation,uniformity and randomness,and the spatial scale of agglomeration feature has reduced from 2008 to 2018.In patch characteristics,the three indicators of CA,NP and MNN had enormous changes,in which CA and NP were positively correlated;minimum MNN has changed from traditional cultivated land to modern orchard,and modern vegetable patch shapes were the most regular.Besides,the single leading factors(distance to river,distance to road and agricultural population density)and interactive factors(distance to river∩elevation and distance to road∩agricultural population density)were critical driving force for the FS evolution.Summarily,this research has reference significance for agricultural land consolidation,FS development and agricultural development mode transformation in study area and other mountainous areas.