The Hydroclimatology of Flash Flooding in Atlanta, Georgia
Speaker: Daniel Wright, Graduate Student
Series: EEWR Brown Bag Seminars
Location: Engineering Quad E219
Date/Time: Friday, February 25, 2011, 12:00 p.m. - 1:00 p.m.
The Atlanta metropolitan area has experienced several severe floods in the past decade. The change of land cover associated with rapid population growth and urbanization leads to pronounced heterogeneities in extreme rainfall and flash flood response across a number of urban catchments. A 10-year radar rainfall dataset for the area has been developed using the Hydro-NEXRAD algorithm, permitting the investigation of urban effects on the initiation and evolution of heavy rainfall events. Radar rainfall fields are constructed at 15 minute time resolution and 1 km spatial resolution; observations from a dense network of rain gages are used for multiplicative bias correction. In addition, the climatology of extreme rainfall-runoff relationships is examined with the aim of improving the understanding of the water balance and flood response of urban catchments during extreme rainfall events. Analyses relating the temporal and spatial distribution of rainfall to basin scale and land-use/land-cover characteristics will assist in developing urban flood frequency relationships. Of particular interest are the floods of September 16, 2004, September 20-22, 2009, and May 3-4, 2010, which caused heavy damage and fatalities in portions of the southeastern US including Atlanta. Similar bias-corrected radar datasets being developed for the Baltimore and Charlotte metropolitan areas will allow for the comparison of climatology of extreme rainfall and urban flooding across the eastern seaboard.