Effects of Global Warming on Hurricane‐Induced Flooding

Global simulation models used to predict climate change typically have resolutions too coarse for resolving small drainage basins, creating a major obstacle to evaluating the hydrologic impacts of climate variability. The writers circumvent this difficulty by using a physical model for severe hurricanes to derive changes in hurricane rainfall under a predicted global warming. The modified rainfall is then transferred to a linked hydrologic‐hydrodynamic model to compute the impact of global warming on hurricane‐induced flooding in a susceptible watershed. As an example, using simulations of tropical, $\mathrm{doubled}‐{\mathrm{CO}}_2$ climate change, the hurricane model predicts a 40% precipitation increase for severe hurricanes affecting southeastern Florida. The 40% increase is assumed for a 100‐year, three‐day event used for flood‐management planning in South Florida and applied to the Basin Runoff and Streamflow Simulation (BRASS) model of the Western C‐11 drainage system. The increased precipitation provokes substantially greater flooding that could negate most of the benefits of present water‐management practices in this basin.