The Impact of Wind on Rainfall Distribution in Urban High-Rise Residential Areas

The spatial distribution of rainfall in urban areas has a significant impact on urban rainfall-runoff processes. Wind can affect raindrop trajectories and thus affect the spatial distribution of rainfall. Due to the obstructive effect of building facades, the influence of wind on the distribution of rainfall is more pronounced in urban areas. In this study, we proposed a method to detect the spatial distribution of rainfall in urban high-rise residential areas based on computational fluid dynamics modeling. The variation of rainfall distribution and the ratio of rainfall on builds to that on the ground with changes in wind speed was analyzed using the proposed method. The results show that: (1) the spatial distribution of rainfall intensity on the ground in the high-rise residential area becomes increasingly uneven with the increase in the wind speed. (2) wind can lead to an increase in the total rainfall in the high-rise residential area by more than twice. (3) the ratio of rainfall on buildings to that on the ground increases significantly with the increasing wind speed.