Understanding Urban Cooling of Blue-Green Infrastructure: A Review of Geospatial Data and Planning Optimization Methods for Mitigating Urban Heat Islands

Many studies aim to assess the characteristics of blue-green infrastructure (BGI) that influence its cooling potential. Commonly used methods include satellite remote sensing, numerical simulations, and field measurements, each defining different cooling efficiency indicators. However, the methodological diversity creates uncertainties in optimizing BGI planning and management. This gap was addressed through a literature review, examining how BGI cools urban space, which spatial data and methods are most effective, which methodological differences may affect the results, and what are current research gaps and innovative future directions. Results suggest that differences in conclusions may arise from geographic and seasonal variations, as well as the spatial resolution of data, model scale, BGI delineation method, cooling range calculation approach, and urban morphology differences. The most influencing BGI characteristics include object size, vegetation fraction, density, height and multi-layering, foliage density, and spatial connectivity. The role of shape complexity remains uncertain across methodological approaches. Future research should prioritize the effects of urban morphology on BGI characteristics effectiveness and explore innovative approaches like Digital Twin technology for BGI management optimization. This paper comprehensively integrates key information related to BGI's cooling capabilities, serving as a useful resource for both practitioners and researchers to support resilient cities development.