8. The Impact of Climate Change on Resilience of Communities Vulnerable to Riverine Flooding

Riverine flooding due to intense precipitation or snowmelt is one of the most devastating natural hazards in the United States in terms of annual damages and economic losses to the built environment and social impacts on communities. Flood inundation mapping, where the likely depths of extreme floods are placed on a map of the community, is important for evaluating flood risks and for enhancing community resilience. However, the Flood Insurance Rate Maps developed by the Federal Emergency Management Agency are not adequate for the evolving needs for community resilience assessment and decision-making over the next century, during which climate change effects are likely to be significant. In this study, we develop a flood hazard modeling framework to support community resilience assessment. This framework couples a hydrological model, which simulates the hydrological processes in a community at a coarser resolution using measured and/or remote sensed precipitation, with a hydraulic analysis module, which computes localized flood depths, velocities and inundated areas at a finer spatial resolution. The Wolf River Basin in Shelby County, Tennessee, which includes the city of Memphis, is used as a testbed to calibrate and validate this coupled model using precipitation and streamflow data obtained from gauge stations operated by the US Geological Survey and to illustrate the potential impacts of climate change in the 21st Century on civil infrastructure, revealing that such impacts are non-negligible but are manageable by proper engineering.