Document Type
Article
Publication Date
1-1-2023
Abstract
Floods inflict significant damage even outside the 100-year floodplain. Thus, restricting flood risk analysis to the 100-year floodplain (Special Flood Hazard Area (SFHA) in the United States of America) is misleading. Flood risk outside the SFHA is often underestimated because of minimal flood-related insurance requirements and regulations and sparse flood depth data. This study proposes a systematic approach to predict flood risk for a single-family home using average annual loss (AAL) in the shaded X Zone–the area immediately outside the SFHA (i.e., the 500-year floodplain), which lies between the limits of the 1.0- and 0.2-percent annual flood probability. To further inform flood mitigation strategy, annual flood risk reduction with additional elevation above an initial first-floor height ((Formula presented.)) is estimated. The proposed approach generates synthetic flood parameters, quantifies AAL for a hypothetical slab-on–grade, single-family home with varying attributes and scenarios above the slab-on-grade elevation, and compares flood risk for two areas using the synthetic flood parameters vs existing spatial interpolation-estimated flood parameters. Results reveal a median AAL in the shaded X Zone of 0.13 and 0.17 percent of replacement cost value ((Formula presented.)) for a one-story, single-family home without and with basement, respectively, at (Formula presented.) and 500-year flood depth (Formula presented.) substantially mitigates this risk, generating savings of 0.07–0.18 and 0.09–0.23 percent of (Formula presented.) for a one-story, single-family home without and with basement, respectively. These results enhance understanding of flood risk and the benefits of elevating homes above (Formula presented.) in the shaded X Zone.
Publication Source (Journal or Book title)
Frontiers in Earth Science
Recommended Citation
Al Assi, A., Mostafiz, R., Friedland, C., Rohli, R., & Rahim, M. (2023). Homeowner flood risk and risk reduction from home elevation between the limits of the 100- and 500-year floodplains. Frontiers in Earth Science, 11 https://doi.org/10.3389/feart.2023.1051546