Assessing the impact of land use changes on urban heat risk under different development scenarios: A case study of Guangzhou in China

Future land use change significantly affects the urban thermal environment, increasing potential urban heat risks. The study of the dynamic changes in land use under future urban development scenarios is still lacking, and insufficient attention has been paid to their underlying impact on urban heat risks. This study introduced an urban heat risk prediction framework to explore the influence of land use change on the distribution of the risk. The Patch-generating Land Use Simulation (PLUS) model was used to model future land use change. Indicators of hazard, exposure, and vulnerability, associated with land use, were set as inputs into the Crichton risk model. The proposed framework was demonstrated under four future urban development scenarios in a high-density city: economic development (ED), natural development (ND), ecological protection (EP), and coordinated development (CD) scenarios. The results showed that the highest growth in terms of land use, population, and economic factors may occur under the ED scenario, followed by the ND and EP scenarios. Compared to land use patterns in 2020, between 4.78 % and 9.40 % of cropland and woodland will be converted into built-up land by 2035. The heat risk index was expected to increase by 3.29 % similar to 4.53 % under the ED and EP scenarios. Meanwhile, a significant percentage (27.66 %) of urban areas were classified as high risk regions under the ED scenario, and were primarily concentrated within the urban center. In addition, high risk areas were expected to expand toward the city's fringes, near its sub-centers, indicating that regions experiencing significant growth will face increased heat risks during future land use changes. This study identified high risk areas under future development scenarios, which offers support for urban planning and the development of mitigation strategies for heat risks.