Optimization of rural settlement layout in karst mountainous areas based on development vitality and point-axis theory: Taking Salaxi Town as an example

Rural settlements serve as spatial carriers for studying human-land relationships in rural areas, and their layout optimization constitutes a crucial approach to promoting comprehensive rural revitalization. Using the rural settlement patches of Salaxi Town in Qixingguan District, Bijie City-a typical karst mountainous town-as a case study, this research examines the impacts of growth poles (areas with concentrated development vitality) and development axes (transport networks) on rural settlement spatial distribution. The findings indicate: ① Significant variations exist in the spatial distribution of development vitality across rural settlements in Salaxi Town, predominantly concentrated in the Sala Community, Chongfeng Village, Shuijinggou Village, Shuanglong Village, Longchang Village, and Gezuo Village; ② Rural settlements in Salaxi Town can be categorized into four optimization types: urban-rural integration, clustered development, relocation and consolidation, and improvement-oriented development; ③ The rural settlements in Salaxi Town can be categorized into four major optimization zones: the Economic Center Zone, the Rural Restructuring Zone, the Relocation and Consolidation Zone, and the Secondary Center Zone. Through spatial guidance and integration strategies tailored to different optimization types, this study provides reference insights for scientific planning of rural settlements in karst mountainous towns.