Hyper-Resolution Flood Modeling Using WRF-Hydro: A Case Study in Urban Charlotte

Advancement in modeling high-impact areas during large flood events is of great interest to communities at risk of flooding and emergency managers in charge of response. Since inundation carries particularly localized impacts that vary with topography, land cover, infrastructure, etc., modeling at shorter time scales (sub-hourly) and at hyper-resolution (30 meters or less) is needed to resolve the unique features. Development of a capability within the Weather Research and Forecasting (WRF)-Hydro model to simulate streamflow and inundated land surface at 10m resolution is a step in achieving street-level information to aid responders and services during a flood. The work described in this presentation focuses on the customization of WRF-Hydro for hyper-resolution, utilizing three events in in the Charlotte, North Carolina region to contextualize the capability and findings. We present an analysis of two key metrics in simulating these flood events: (1) streamflow, comparison of observations and simulations at 25 gauge locations; (2) inundation height and extent, validation with observed high water marks. Discussion of the utility and skill of the model simulations are presented, as well as the limitations of the model itself and the validation and evaluation approaches.