高山贫困地区农村居民点空间格局演变特征及驱动机制

Spatial pattern evolution characteristics and driving mechanism of rural settlements in high mountain areas with poverty

科学开展高山贫困地区农村居民点空间格局演变特征及驱动机制研究,可为山区乡村空间治理和脱贫攻坚提供一定的基础支撑和指导意义。该研究以秦巴山区腹地原国家级贫困县湖北省十堰市房县为典型案例,基于GIS、地形梯度分析法、分形理论和地理探测器模型对高山贫困地区农村居民点的空间格局演变特征及驱动机制进行探究。结果表明:1)2001—2018年房县农村居民点空间扩张显著,斑块密度减小,平均斑块规模增大;分布指数随着地形梯度等级升高而逐渐减小,且在2013—2018年内变化幅度最大,表明房县农村居民点向着地形条件优越的低梯度区域集聚发展特征愈发显著;2)房县农村居民点空间结构和形态均具有较强的分形特征,表现为空间聚集维数减小,集聚特征增强;形态维数减小,斑块形状越来越规整,空间形态趋于简单;稳定性指数增大,居民点呈现规则有序的扩张和发展态势;3)自然地理要素是影响山区农村居民点空间格局演变的基本因素,社会经济和区位条件是山区农村居民点分布格局变化的重要因素,而"增减挂钩"和"扶贫搬迁"等政策要素进一步驱动着山区农村居民点空间格局演变,这对2013年后农村居民点空间格局演化产生了重要影响。

Rural settlements include the mainly populated areas for farm production and living.The shape of settlement boundaries is ever changing with the rapid development of the socio-economy in rural areas of China.The purpose of this study is to explore the spatial pattern evolution and driving factors of rural settlements in poverty mountain areas.Taking the Fang County of Hubei Province as a typical case,the geographic information systems(GIS),topographic gradient,and fractals were utilized to analyze the spatial variation in the boundaries of rural settlements from 2001 to 2018,with emphasis on the scale,form and spatial distribution.The regional topographic gradient included the elevation,slope,and topographic index.The fractal analysis was related to the aggregation and morphological dimension.Meanwhile,a geographical detector model was also established to investigate the driving mechanism.Some suggestions were made for the policy of linking the increase and decrease of urban and rural construction land(Link Policy),and targeted poverty alleviation relocation(TPAR),together with physical geography,socio-economy,and location conditions.The results showed that:(1)There was a significant change in the scale,density,and spatial distribution of rural settlements in Fang County from 2001 to 2018.The spatial expansion dominated the rural settlements,where the plaque density decreased,while the average plaque size increased.The distribution index of rural settlements gradually decreased with the increase of topographic gradient grades.The largest change occurred between 2013 and 2018,indicating that rural settlements tended to be concentrated in the low-gradient areas with superior topographic conditions.(2)There was a quite strong fractal feature in both spatial structure and morphology of rural settlements,showing a decrease in the spatial dimension and an enhanced characteristic of the aggregation.The morphological dimension decreased,indicating that the shape of aggregation plaque was more regular,and thereby the spatial form was tending to be simple.In addition,the stability index increased,indicating an orderly developing trend of rural settlements.(3)The fundamental factor was natural geography,and the important factors were the socio-economy and location conditions for the pattern change of rural settlements in mountainous areas.The Link Policy and TPAR further promoted the rural settlements from the small-scale decentralized regions to the concentrated valley and plain with better terrain and location.There was a significant impact of Link Policy and TPAR(quantified as policy factors)on the spatial pattern evolution of rural settlements after 2013.The finding can provide practical support for the optimization of rural settlements and revitalization in mountainous areas.