Analysis On The Spatial Pattern Of Sloping Farmland And Abandoned Land In Fengjie County Of The Three Gorges Reservoir

Farmland is the basic resource for human survival and development.With the raid process of national new urbanization,industrialization and agricultural modernization,due to poor conditions,the reform and adjustment of agricultural structure and agricultural production efficiency,the diverse family incomes,the land in the mountainous region marginal is decreasing.The phenomenon of abandoning farmland appeared.Study on the spatial distribution pattern of abandoned land and its relationship with sloping farmland land in the underdeveloped mountains area,will contribute to the reasonable regulation of the mountainous land,improve land use efficiency,and accelerate the integration of urban construction,improving the rural ecological environment and food security.Taking Fengjie County of the Three Gorges Reservoir Area as the study area,using ArcGIS 10.2 and Fragstas 4.2 software,analysis on spatial pattern and factors of sloping land and abandoned land from multi-level and multi-angle,combined with the typical rural cottage in the Town,in order to reveal the space characters and influence mechanism of abandoned land in Fengjie County.(1)Spatial distribution characteristics of sloping farmland and abandoned land.Sloping farmland and abandoned land in various geomorphic regions showed similar characteristics,aggregation intensity from high to low was the southern middle mountains-karst area,the northern hilly area,Yangtze River Valley area,southern low mountains-valley area,northern middle mountains-karst area.The the sloping farmland and abandoned land within 0.5hm~2 were mainly distributed in northern hilly area.The sloping farmland whose area was 0.5~1.5 hm~2 was mainly in low mountains-valley area and southern middle mountains-karst area.The the sloping farmland beyound 1.5 hm2was mostly in Yangtze River Valley area.The abandoned land whose area was above 0.5 hm~2 usually distributed in southern middle mountains-karst area.(2)Spatial relationship between sloping farmland and abandoned land The density and spatial proportion of slope farmland and abandoned land varied greatly in the unit grid,and a significant spatial correlation was showed.The"less abandoned land"was proved the main type,and the"more abandoned land"was merely located in the mountain ranges,the strikes of which were EW and NE to SW.Specific spatial combination patterns were summed up:A.The Settlements were scarce,the sloping farmland were concentrated,and the abandoned land is distributed around the remote small settlements.B.Both settlements and sloping farmland were concentrated,but abandoned land were scarce.C.Settlements were scarce,sloping farmland were scattered,and abandoned land were concentrated.D.Settlements were concentrated and the number of sloping farmland and abandoned land were more.(3)Factors affecting the spatial distribution of sloping framland and abandoned land Affected by elevation,slope,lithology,traffic and location conditions,the spatial differentiation characteristics of sloping farmland and abandoned land wre notable,and showed the restriction of distance.The PD of abandoned land was greater than the sloping farmland in the condition of same area level under the specific distance scales.The larger the area of sloping farmland and abandoned land,the higher the value of MSI,the larger the value of MNN.The MNN of abandoned land was greater than the sloping farmland in the condition of same area level.(4)Spatial and temporal evolution of abandoned farmland in sloping fields:a case study of CaoTang town The number of high density of sloping farmland in Caotang town within 2012-2017 decreased,and transferred from the central region to the East and the west.Abandoned land transferred from the eastern and western region to the north,and the degree of space uniformity is increased.The number of abandoned land with<2 years was smaller,the patches area was large,and the shape was the most irregular.The distribution range of abandoned land with 2~5 years and 5~10 years was wide.The number of sloping farmland with>10 years is more,the patches area is small.The complexity of the edge of abandoned land in each period is roughly the same.Affected by terrain,traffic and location conditions,the degree of abandonment of sloping farmland varied significantly.