Influence of Urbanization on Precipitation and Flooding Caused by Landfalling Hurricanes along the U.S. Coast

We examine the impact of urbanization on precipitation and flooding caused by hurricanes that made landfall along the U.S. coast under a dynamical modeling framework, using Hurricanes Harvey and Barry as two case studies. Hurricane Harvey poured more than a metre of rainfall across the heavily populated Houston area, leading to unprecedented flooding and damage. Although studies have focused on the contribution of anthropogenic climate change to this extreme rainfall event, limited attention has been paid to the potential effects of urbanization on the hydrometeorology associated with this hurricane. Here we find that urbanization exacerbated not only the flood response but also the storm total rainfall. Using the Weather Research and Forecast model—a numerical model for simulating weather and climate at regional scales—and statistical models, we quantify the contribution of urbanization to rainfall and flooding. In addition, we examine the impacts of urbanized area in New Orleans, Louisiana on the precipitation caused by the 2019 landfalling Hurricane Barry. Based on the results of these analyses, the effect of urbanization on storm-induced extreme precipitation and flooding should be more explicitly included in global climate models, and this study highlights its importance when assessing the future risk of such extreme events in highly urbanized coastal areas.