Multidimensional Analysis of the Population–Land–Economic Vitality Nexus: Coordination, Decoupling, Efficiency, and Development Typologies in the Jinan Metropolitan Area

Under the Yellow River Basin’s strategic imperative of ecological protection and high-quality development, the critical question is whether rapid urbanization’s population agglomeration and land expansion are genuinely aligned with-or increasingly decoupled from-underlying economic vitality. To address this, we construct a unified analytical framework that synchronously captures coupling coordination, decoupling trajectories, and land-use efficiency, operationalized through multi-source county-level panel data for the Jinan Metropolitan Area in lower Yellow River Basin across 2000, 2010, and 2020. Unlike conventional two-dimensional assessments, the framework distinguishes system coordination, evolutionary direction, and input–output performance while using harmonized nighttime light data to capture the spatial intensity of economic vitality. The results show that: (1) the mean county-level coordination grade increased from 4.76 to 5.32, although strong core–periphery disparities persisted; (2) the decoupling structure shifted from relative homogeneity to pronounced differentiation, and strongly decoupled counties accounted for 48% of all units by 2020; and (3) average efficiency rose from 0.25 to 0.39, but most counties remained below the efficiency frontier, producing a pattern of central agglomeration and peripheral dispersion. Cross-classification further identifies coordinated but inefficient, efficient but dysfunctional, and low-coordination–low-efficiency trajectories that cannot be detected using a single model. The framework therefore provides a transferable diagnostic tool for differentiated territorial planning in metropolitan regions undergoing rapid structural transformation.