Spatiotemporal Differentiation and Evolution of the Coupling Coordinated Development of Transportation, Population, and Ecology on the Qinghai–Tibet Plateau

Abstract

Coupling coordination analysis provides a quantitative basis for balancing development and conservation in ecologically fragile regions; however, existing frameworks are predominantly designed for urban agglomerations and seldom integrate transportation, population, and ecology at fine spatial scales. This study develops a township-scale analytical framework that combines ecosystem service value (ESV) accounting, subsystem development evaluation functions, and a coupling coordination degree model, and applies it to the Qinghai–Tibet Plateau (QTP) for the period 2000–2020. Road density and potential accessibility characterize the transportation subsystem; population size and density characterize the population subsystem; and the Normalized Difference Vegetation Index (NDVI), Net Primary Productivity (NPP), and ESV characterize the ecological subsystem. Entropy weights are assigned within each subsystem, and spatial autocorrelation together with cold and hot spot analysis is used to identify differentiation patterns. The application demonstrates that the framework effectively captures the spatiotemporal differentiation of coupling coordination at the township scale: on the QTP, the coordination level retreated from good coordination to primary coordination during 2000–2020, with the decline concentrated in 2010–2020; coordinated townships remained confined to central towns and their surroundings, whereas low-coordination areas were contiguously distributed across ecologically sensitive zones. The framework is transferable to other regions facing similar development–conservation tensions and can support territorial spatial planning and ecological security management. The QTP application further suggests that, in plateau contexts, coupling coordination outcomes should be interpreted jointly with regional functional orientations such as ecological red lines.