Research on the Differentiation Pattern and Sustainable Optimization of Residential Employment Relationships in Linear Cities: A Case Study of Lanzhou, China

The spatial matching of jobs and housing is central to urban operational efficiency, congestion alleviation, and sustainable development. River-valley linear cities face unique jobs–housing challenges due to rigid topography. Taking the main urban area of Lanzhou, a typical linear city, as a case study, this research uses large-scale Location-Based Service (LBS) data and integrates kernel density estimation and Ordinary Least Squares (OLS) to analyze commuting behavior, jobs–housing balance, driving mechanisms, and associated sustainability effects. The results indicate that (1) commuting exhibits a prominent “east–west corridor” pattern; constrained by rigid topography, its efficiency is lower than that of plain linear cities, increasing energy consumption and emission pressures. (2) The jobs housing ratio shows significant spatial differentiation, with employment surplus in the core area and “dormitory town” characteristics in peripheral clusters, raising social equity concerns. (3) Topographical features (“two mountains flanking a river”) form the rigid foundation of the jobs–housing landscape, while unbalanced industrial layouts and concentrated public service resources are the primary socio-economic drivers of jobs housing separation. From a sustainability perspective, these patterns generate coupled environmental, economic, and social effects: corridor commuting intensifies congestion and emissions, jobs–housing mismatch raises commuting costs and reduces labor-market efficiency, and peripheral residents face longer commutes and unequal access to jobs and services. This study provides a theoretical basis and policy references for spatial optimization, low-carbon commuting, and equitable development in topographically constrained linear cities.