Quantifying the cooling effect of ecological spaces within the built-up area of Lanzhou City

This is the authors' abstract. We don't add key points for this paper.

Urban ecological spaces play an important role in reducing the urban heat island effect and improving resilience to heat waves under climate warming. This study focuses on Lanzhou, a typical river-valley city, and examines the cooling processes and mechanisms of urban ecological spaces to improve understanding of their thermal regulation effects. The results show that: (1) within the built-up area, constructed land and unused land generally had higher surface temperatures than ecological spaces in summer, which suggests that ecological spaces can help reduce urban heat; (2) The regional mean annual ET-based latent heat absorption per unit area of ecological spaces reached 5.75 × 10 5 kJ/(m 2 ·a); (3) the cooling effect varied among ecological space types. About 60% of ecological spaces showed a cooling effect. Wetland showed the largest cooling-related value (0.34 °C), followed by forest (0.31 °C) and grassland (0.23 °C). These results show the importance of ecological space allocation in urban climate adaptation. We suggest that urban planning should give more attention to the scientific configuration of ecological spaces under increasing heat-wave risk.