基于3D理论与SEM的县域交通可达性与空间贫困的耦合机制

为获取连片特困地区县域交通可达性与空间贫困程度之间的耦合关系，运用路网-栅格集成法的加权时间成本距离模型对县域综合交通可达性进行测算，构建了基于“3D”理论的空间贫困评价指标体系，基于结构方程模型获取了二者的空间耦合机制，并以滇西边境山区为例进行分析验证。结果表明：滇西边境山区各贫困县（区）可达性水平的空间分异特征显著，且邻近效应突出，骨干路网的完善在一定程度上提高了贫困县域的县外可达性水平；滇西边境山区的贫困发生率呈现中心发散、集聚分布的空间特征，贫困程度的改善与地均GDP、市场距离、产业距离、交通分割、贫困分割呈正向相关，与地均人口密度呈负相关；区域空间贫困程度与交通可达性的耦合强度为023，呈显著负向影响。通过提升可达性水平和县域间通达程度，可为扶贫攻坚和经济社会发展提供有力支撑

Coupling Mechanism of County Traffic Accessibility and Spatial Poverty Based on 3D Theory and SEM:A Case Study in Mountains Border Regions of Western Yunnan

In order to obtain the coupling relationship between the accessibility and the degree of spatial poverty in the counties, this paper first uses the weighted time cost distance model of the road network and grid integration method to calculate the traffic accessibility of the county, and constructs the spatial poverty evaluation index system based on “3D” theories, respectively. Then, the spatial coupling mechanism of the traffic accessibility and spatial poverty is obtained based on the structural equation model, taking Western Yunnan border area as an example. The results show that first there are significant spatial differentiation and proximity effect of the poor counties (regions) in the western Yunnan border area. Improving the backbone road network has a positive relationship with the outside accessibility of counties. Second, the incidence of poverty in the western Yunnan border area shows the spatial characteristics of divergence and agglomeration distribution. The poverty alleviation is positively related to GDP per land, market distance, industrial distance, traffic segmentation and poverty segmentation. However, it has a negative effect on population density. Third, the coupling intensity of spatial poverty and traffic accessibility in this region is 023, showing significant negative interactions. Improving the whole accessibility level especially that between counties could provide strongly support for poverty alleviation and the development of social economics