This study quantifies how urbanization and climatological trends influenced flooding in the greater Houston region during Hurricane Harvey. The region – characterized by extreme precipitation events, low topographic relief, and clay-dominated soils – is naturally flood prone, but it is also one of the fastest growing urban areas in the United States.
This rapid growth has contributed to increased runoff volumes and rates in areas where anthropogenic climate changes has also been shown to be contributing to extreme precipitation. To disentangle the relative contributions of land use/land cover and climatic changes on flooding during Hurricane Harvey, the study simulates catchment response using a spatially-distributed hydrologic model under 1900 and 2017 conditions.
This approach provides insight into how timing, volume, and peak discharge in response to Harvey-like events have evolved over more than a century. The findings demonstrate that the combined impacts of urban development and climate change nearly doubled peak discharge in the Houston area during Harvey compared to a similar event in 1900. The study also found that land use change has magnified the effects of climate change on catchment response. These findings support a precautionary approach to flood risk management that explicitly considers how current land use decisions may impact future conditions under varying climate trends, particularly in low-lying coastal cities.