三峡库区腹地规模农地空间分布规律

山区农业转型对于我国山区耕地可持续利用效率、土地整治方向以及生态建设方向具有一定的指导意义,渝东北生态涵养发展区是重庆市农用地整治项目的主要分区,通过定义作为农业转型产物的"规模农地"相关概念及其判读标准,旨在提出一种新的研究路径对重庆市典型山区地貌的耕地利用现状给予指导和改善意见。首先选取三峡库区腹地5个区县为研究区,并结合研究区实际对"规模农地"进行等级划分,利用Arc GIS10.2等软件通过景观格局指数、核密度测算、空间自相关等方法从斑块特征、数量分布、空间格局三方面对研究区内规模农地的空间分布规律进行探讨。研究表明:(1)不同类型规模农地斑块特征呈现一定的规律性,小规模农地斑块密度最大为6.004,大规模农地平均最近指数MNN值最低为643.401,且农地规模越大,面积加权平均斑块分维数AWMPFD值和聚集度AI值越高;(2)中、大规模农地数量多集中在奉节县,微、小规模则多集中在巫山县,且规模农地自身及其相互之间存在固定的邻接性规律,即同类斑块之间的邻接性与其斑块大小成反比,不同类型斑块之间则与之相反;(3)研究区规模农地整体空间分布主要集中在奉节县中部以及巫溪县东部,沿江流域的平坝地区分布相对密集,且不同类型规模农地在空间上存在明显的自相关性。

SPATIAL DISTRIBUTION LAW OF SCALE FARMLAND IN THE HINTERLAND OF THE THREE GORGES RESERVOIR AREA

Making a study on the mountain agricultural transformation plays a guidance role in the sustainable utilization of cultivated land,and it is also important for the improvement of land consolidation and ecological construction in China.The ecological conservation area in Northeast is the main partition of agricultural land consolidation project in Chongqing City.By defining the concept of "scale farmland",this paper aims to propose a new research path to put forward a new research approach to guide and improve the utilization of cultivated land in typical mountainous areas of Chongqing.In this paper,five districts and counties of the Three Gorges Reservoir areas were selected as the study area,combined with the actual research area to classify the scale farmland.By using ArcGIS10.2 software and other landscape pattern index,kernel density estimation and spatial autocorrelation method to discuss the spatial distribution of " scale farmland" from three aspects:patch characteristics,quantity distribution and spatial pattern.The results showed that:(1)The characteristics of different types of scale farmland patches showed a certain regularity,The patch density of small-scale farmland was the largest 6.004,and the value of MNN of large-scale farmland was the lowest 643.401,and the larger the farmland scale,the higher the weighted average patch fractal dimension (AWMPFD) value and the aggregation (AI) value;(2) The number of large and medium scale farmland were concentrated in Fengjie County,and the micro scale and small scale farmland were mostly concentrated in Wushan County,and the scale farmland itself existed a fixed adjacency law.The adjacency between the same kind of pathches were inversely proportional to the patch size,while the adjacency Law of different types of pathes were opposite;(3) The spatial distribution of scale farmland in the study area mainly concentrated in the middle of Fengjie county and the eastern part of Wuxi County,but the river valley Pingba area was relatively dense,and the different types of scale farmland had obvious self-correlation in space.