Understanding Urban Cooling of Blue–Green Infrastructure: A Review of Spatial Data and Sustainable Planning Optimization Methods for Mitigating Urban Heat Islands

<p>Many studies in the literature have assessed the blue–green infrastructure (BGI)<br>characteristics that influence its cooling potential for sustainable urban development. Common<br>assessment methods include satellite remote sensing, numerical simulations, and field<br>measurements, each defining different cooling efficiency indicators. This methodological<br>diversity creates uncertainties in optimizing BGI management. To address this, a literature<br>review was conducted using Google Scholar,Web of Science, and Scopus, examining how<br>the BGI cools urban space, which spatial data and methods are most effective, which<br>methodological differences may affect the results, and what the current research gaps<br>and innovative future directions are. The results suggest that remote sensing is ideal for<br>large-scale BGI comparisons, numerical simulations for local development scenarios, and<br>field measurements for assessing conditions closest to residents. Maximum BGI cooling<br>intensity averages show 4 ◦C from remote sensing, 3 ◦C from field measurements, and<br>2 ◦C from numerical simulations. Differences in conclusions may arise from differences<br>in the data resolution, model scale, BGI delineation method, and cooling range calculation.<br>The key BGI characteristics include object size, vegetation fraction, foliage density,<br>and spatial connectivity. Future research should prioritize the integration of the different<br>methods, BGI shape complexity effectiveness assessment, and effects of urban morphology<br>on evaluating BGI characteristics’ effectiveness, and explore digital twin technology for<br>BGI management optimization. This study integrates key information on BGI’s cooling<br>capabilities, serving as a useful resource for both practitioners and researchers to support<br>resilient city development</p>