Assessing the spatial development of HSR station areas: a method integrating compact city and eco-city principles for building environment

Planning high-density high-speed rail (HSR) station areas in Asia faces a persistent dilemma: balancing intensive land use with ecological conservation. To address the lack of diagnostic tools quantify the complex interplay between spatial compactness and ecological constraints, this study develops an integrated planning support framework. The framework innovatively couples a “natural-industrial-social” tri-dimensional compactness evaluation with a multi-factor ecological constraint analysis. This is operationalized through a comprehensive indicator system encompassing 31 metrics, weighted by a combined PAC and AHP-CRITIC method, and a coupling coordination degree (D-value) model quantifies synergy levels. Empirically applied to 16 station areas along China’s Chengdu-Chongqing axis (2015–2025), the framework yields three key findings: (1) ecological constraints exhibit a “double-edged sword” effect, promoting natural compactness while inhibiting industrial-economic agglomeration; (2) socio-public space compactness adheres to a service-provision principle, independent of ecological constraints; (3) based on these mechanisms, four distinct spatial development typologies are identified – High-level Stable, Synergistic Leapfrogging, Structural Decline, and Lagging Low-coordination. This research provides a practical tool for planners, enabling a shift from passive evaluation to proactive impact diagnosis and risk early-warning. The findings offer evidence for formulating differentiated spatial governance and design strategies toward sustainable built environments around transport nodes.