Optimizing local climate zones to mitigate urban heat risk: A multi-models coupled approach in the context of urban renewal

Abstract

Rapid urbanization has substantially transformed the material and energy cycling processes within urban systems. This transformation has intensified the urban heat island (UHI) effect and exacerbated heat-related environmental degradation and public health risks. Local Climate Zones (LCZs), a classification system rooted in similar urban morphological characteristics, provide a valuable framework for analyzing urban thermal environments. Optimizing LCZ configurations to mitigate heat risk offers a scientific basis for multi-scale and context-specific spatial governance. However, existing research seldom integrates LCZ optimization with practical urban renewal strategies. Furthermore, current optimization efforts often prioritize theoretical optima without assessing implementation feasibility. To address these limitations, this study applied the NSGA-II algorithm to optimize LCZ configurations with dual objectives: minimizing heat risk and structural disruption. The FLUS model was subsequently employed to simulate the spatial and quantitative transformation of the optimized LCZ configurations. This approach innovatively introduces an LCZ optimization strategy from the perspective of urban renewal. Implemented in four central districts of Guangzhou, namely Tianhe, Liwan, Haizhu, and Yuexiu, the proposed approach reduced the total heat risk value by 33.14 units through the adjustment of 2088 LCZ-classified grid cells. However, under practical transformation constraints, FLUS model simulations achieved only 48.52 % of the theoretical optimum. This discrepancy underscores the necessity for dual-scale planning strategies that combine macro-scale LCZ configurations optimization with micro-scale urban morphological refinement. Such integrative approaches can enhance urban resilience and support climate-adaptive urban renewal.