Development vs. conservation in limited urban sprawl: An integrated framework for resolving the urban boundary dilemma in China

The strategic delineation of the urban development boundary (UDB) is an effective initiative for efficient land resource allocation and for facilitating planned urban development. To align with sustainable development objectives, UDB definitions have evolved to reconcile urban development with ecological preservation. This study presents a UDB delineation framework from an integrated perspective that incorporates both demand-oriented and comprehensive constraints. Specifically, the urban construction land demand area was estimated based on population projections, meanwhile, the ecological red line (ERL) was delineated and integrated into the evaluation of the construction land suitability. Subsequently, with the demand area as the simulation target and unsuitable areas as comprehensive constraints, the UDB was delineated by simulating future land use patterns. The proposed framework was applied to Wuhan, a rapidly urbanizing city in central China, where the delineation of the UDB serves the dual purpose of managing the rapid expansion of built-up land and achieving a harmonious balance between urban development imperatives and ecological protection goals. Moreover, based on the results and analysis, policy implications for the rational spatial planning of Wuhan were proposed, encompassing the spatial patterns and scientific decision-making in ecological conservation and urban development. The results demonstrate that the efficacy of adopting a comprehensive perspective in delineating UDB effectively reconciles the competing needs of urban development and conservation. The framework and the policy insights derived in this study could inform spatial planning efforts not only in Wuhan but also in other cities facing the dilemma of urban development and ecological protection.