Designing multisource blue-green cooling networks by coupling landscape pattern metrics and circuit theory.

The surface urban heat island effect is a growing environmental concern amid accelerating urbanisation and climate change, posing significant threats to sustainable development and public health. While urban green spaces are recognised as effective in mitigating the surface urban heat island effect, most studies focused on isolated patches or local interventions, and thus lack a systematic, network-based cooling strategy. This study proposes an integrated framework of “cool-source identification–ventilation corridors–network integration”, combining multi-source remote sensing data (2003–2022), the geographic detector model, morphological spatial pattern analysis, and circuit theory to assess surface urban heat island dynamics and construct an urban green cooling network. Focusing on Nanchang’s central urban area, results indicate that from 2003 to 2022, the proportion of low-temperature zones decreased from 41.69% to 19.67%, while high-temperature zones increased from 8.69% to 19.89%; correspondingly, the surface heat island imbalance index rose from − 0.491 to 0.005. The interaction between the normalised difference vegetation index and land use explained over 60% of the surface temperature variation. A green ecological network comprising 56 primary and 60 secondary ventilation corridors was established, significantly enhancing connectivity and heat dissipation potential. Building on previous studies, this network demonstrates the capacity to reduce daytime temperatures by 1–3 °C in densely built-up areas. The findings highlight that optimising the spatial configuration and connectivity of green spaces can maximise cooling benefits under land constraints. This blue–green ventilation integrated approach provides transferable insights for humid, flat and rapidly urbanising regions.