Economic Modeling of Flood Damages in Near Flat Topographic Cities: Key Considerations

摘要

Federal flood risk management studies are typically conducted in accordance with policies and guidelines pertaining to water resources planning, particularly the Water Resource Council's Economic and Environmental Principles and Guidelines for Water and Related Land Resources Implementation Studies and the U.S. Army Corps of Engineers Planning Guidance Notebook (ER 1105-2-100). The Federal objective for such studies is to identify a flood damage reduction plan that contributes to National Economic Development (NED) consistent with protecting the nation's environment, applicable executive orders, and other Federal planning requirements. As such, the feasibility of an NED plan is highly contingent on having accurate flood damage economic models for quantifying the extent of flood damages and assessing plan performance. This paper discusses the use of HEC-FDA for computing flood inundation damages using risk and uncertainty analysis techniques, with emphasis on low-slope urban developments. Experience from studies show that subtle changes to a plan's economic configuration, or the existence of slight inaccuracies in structure data, can yield substantial differences in flood damage results. Such discrepancies have the potential to over-estimate damage reduction benefits (or understate, as is the case with repetitive loss structures not included in the structure database) from proposed plans, thereby hindering a plan's final selection. These differences highlight the need for improved structure data collection techniques and model refinement for providing effective economic modeling of flood damage reduction solutions.