Ashley, Walker S.
M.S. (Master of Science)
Department of Geography
Flood control--Georgia--Atlanta||Floodplain management--Georgia--Atlanta||Urban runoff--Georgia--Atlanta--Management||Spatial analysis (Statistics)
Financial losses due to flooding have increased substantially over the past several decades. Previous research implies that flood losses are rising due to changes in precipitation and increases in exposure. While prior research has explored changes in floodplain exposure at the county level, few efforts have examined patterns across an entire metropolitan area. This thesis examines changes in residential built-environment flood exposure within the current boundaries of the Atlanta, Georgia metropolitan statistical area by estimating the number of housing units that are located within the floodplains of the region. Housing unit data at the block level from the 1990-2010 decennial censuses are used to estimate housing unit exposure to floods using a binary dasymetric and proportional allocation method. Due to concerns about flood model accuracy and the fact that regulatory 500-year floodplains have not yet been delineated for all parts of the study area, three different representations of the 100-year (1 percent annual chance) and 500-year (0.2 percent annual chance) floodplain are employed: the generally more conservative floodplains created using the Federal Emergency Management Agency's Hazus-MH software, the generally more extensive floodplains included in the proprietary Flood Hazard Data product from KatRisk LLC and the regulatory floodplains from the NFIP. It was found that residential exposure within both the 100 and 500-year floodplain increased from 1990-2010 throughout the Atlanta region. The NFIP appeared to be marginally effective overall. Regulatory 100-year floodplain development was most likely to be favored over development outside the floodplain where overall development was strong or on the edge of the developing area. Development within the marginal 500-year was favored near the core of the urban area. Results using the KatRisk product reveal both greater overall exposure and a greater increase in exposure within the 100-year floodplain than the regulatory product suggests. Overall, the results argue that heightened flood exposure is, along with changes in precipitation and runoff, an important factor to consider when addressing the impact of the flood hazard.
Ferguson, Alex Page, "Spatiotemporal analysis of residential flood exposure in the Atlanta, Georgia metropolitan area, 1990-2010" (2016). Graduate Research Theses & Dissertations. 5003.
ix, 93 pages
Northern Illinois University
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