Quantifying urban hydrological processes effects on urban climate: A perspective from a novel parameterization scheme

Abstract

Cutting-edge urban canopy parameterization techniques were employed to investigate the impacts of urban hydrological processes. We conducted three one-month simulation tests to quantify the impact of urban hydrological processes on urban climate, which is induced by urban ground greening, green roofs and surface water. It is found that urban hydrological processes significantly reduce maximum temperatures and improves comfort, especially during heatwaves, but its effect on mean air temperature was found to be less pronounced. Compared to ground greening, green roofs provide enhanced cooling advantages. Overall, all three hydrological processes produce a more spatially dispersed distribution of precipitation with a reduction of 25 % in total precipitation amount. This can be attributed to the mitigation of urban heat island intensity by latent heat and the stabilization of the planetary boundary layer. The finding has implication for the measures that can be taken in mitigating the adverse impact induced by rapid urban expansion.