基于景观格局的山地型农村居民点空间分布特征及影响因素研究——以南江县为例

On Spatial Distribution Characteristics and Influencing Factors of Mountainous Rural Settlements Based on Landscape Pattern-A Case Study of Nanjiang County

农村居民点是农村区域空间人口聚集形态的表现形式,也是乡村聚落景观的重要组成部分。为研究山地型农村居民点空间分布特征及影响因素,本文以巴中市南江县为例,以南江县国土变更调查数据、哨兵数据和DEM数据等为基础,用核密度估计、最邻近距离的分析方法来研究南江县农村居民点的空间分布特征;用景观格局分析法结合缓冲区分析,并借助地理探测器,从景观生态学的角度分析影响农村居民点空间分布的因素。结果表明:(1)南江县农村居民点在中南部的低山地区分布密集,而北部中山区分布稀疏,且南江县农村居民点从单核式的大集中格局,逐渐转变为多点式的大分散,小集中格局。(2)从景观格局指数进行分析,2016—2022年间,高程、坡度、河流、道路、镇区五个因子对农村居民点的规模和景观破碎程度有着较大的影响。其中河流、道路、镇区三个因子随着城镇化进程的加快,对农村居民点的影响有不同程度的改变。(3)结合地理探测器和景观格局指数,高程是农村居民点空间分布的主导因素,而由于城镇化的影响,镇区对农村居民点的影响力进一步提高,而河流的重要性略有降低。并且各因子之间的交互作用都表现为双因子增强和非线性增强。

Rural residential area is the expression form of spatial population aggregation in rural areas,and it is also an important part of rural settlement landscape.In order to study the spatial distribution characteristics and influencing factors of mountainous rural settlements,taking Nanjiang County,Bazhong City as an example in this paper,the spatial distribution characteristics of rural settlements in Nanjiang County were studied based on the land change data,sentinel data and DEM data by using the methods of kernel density estimation and nearest neighbor distance analysis.The factors affecting the spatial distribution of rural settlements were analyzed from the perspective of landscape ecology by using landscape pattern analysis combined with buffer zone analysis and geographical detector.The results showed that:(1)The rural residential areas in Nanjiang County were densely distributed in the low mountain areas in the central and southern parts of the county,while the distribution was sparse in the middle and mountainous areas in the north.Moreover,the rural residential areas in Nanjiang County had gradually changed from a single-core pattern of large integration to a multi-point pattern of large dispersion and small integration.(2)According to the analysis of landscape pattern index,the scale and landscape fragmentation degree of rural settlements during 2016—2022 were affected by five factors,namely elevation,slope,river,road and town area.With the acceleration of the urbanization process,the three factors,river,road and town,had different degrees of influence on rural residential areas.(3)Combined with the geographical detector and landscape pattern index,elevation was the dominant factor in the spatial distribution of rural settlements.However,due to the influence of urbanization,the influence of towns on rural settlements further increased,while the importance of rivers slightly reduced.And the interaction between each factor was double factor enhancement and nonlinear enhancement.