Indicators and methodologies for assessing urban agglomeration sustainability.

Urban agglomerations are crucial for achieving the United Nations Sustainable Development Goals (SDGs). However, uncertainties remain in the indicators and methodologies used to measure their sustainability. This paper establishes and analyzes the SDGs network at national and urban agglomeration levels, highlighting that urban agglomerations are key scale to achieving sustainable development but are far more complex than a single city scale. Then, this paper proposes an assessment framework for urban agglomeration, which includes indicators, methodological approaches, and validation processes. By introducing the multi-level coupling coordination degree, various influencing mechanisms are integrated into the evaluation stage. In addition, this paper constructs redundancy and sensitivity analyses and establishes a correlation network between indicators and SDGs to collectively validate the robustness and international compatibility of the indicator system. This study provides strong support for understanding and promoting the sustainable development of urban agglomerations, contributing to the achievement of the 2030 Agenda.