Influence of wind-driven rain on the rainfall-runoff process for urban areas: Scale model of high-rise buildings

Abstract

The hydrological response of impervious urban areas with varying building densities to the combined action of wind and rain is not well understood. Exploratory laboratory simulations were conducted using a scale model of a hypothetical high density urbanized area with high-rise buildings. Seventy two runs were conducted for static and moving storms in upstream and downstream directions, with and without wind, for different building densities and for an average rainfall intensity of 120 mm/h. The laboratory experiments show that building density and the spatial and temporal distribution of rainfall that results from wind and storm movement have a clear influence on the hydrological response to rainstorms. Increased urbanization promotes a higher peak discharge, a longer base time and reduces the slope of the hydrographs rising limbs, while wind-driven rain attenuates these effects. Downhill storm movement promotes a faster hydrological response and a higher discharge peak than uphill movement.