Flood risk assessment for residences at the neighborhood scale by owner/occupant type and first-floor height

Ayat Al Assi; Rubayet Bin Mostafiz; Carol J Friedland; Md Adilur Rahim; Robert V Rohli

doi:10.3389/fdata.2022.997447

Flood risk assessment for residences at the neighborhood scale by owner/occupant type and first-floor height

Front Big Data. 2023 Jan 9:5:997447. doi: 10.3389/fdata.2022.997447. eCollection 2022.

Authors

Ayat Al Assi^{1

2

3}, Rubayet Bin Mostafiz^{2

3

4}, Carol J Friedland^{2

3}, Md Adilur Rahim^{2

3

5}, Robert V Rohli^{3

4}

Affiliations

¹ Bert S. Turner Department of Construction Management, Louisiana State University, Baton Rouge, LA, United States.
² LaHouse Resource Center, Department of Biological and Agricultural Engineering, Louisiana State University Agricultural Center, Baton Rouge, LA, United States.
³ Coastal Studies Institute, Louisiana State University, Baton Rouge, LA, United States.
⁴ Department of Oceanography and Coastal Sciences, College of the Coast and Environment, Louisiana State University, Baton Rouge, LA, United States.
⁵ Engineering Science Program, Louisiana State University, Baton Rouge, LA, United States.

Abstract

Evaluating flood risk is an essential component of understanding and increasing community resilience. A robust approach for quantifying flood risk in terms of average annual loss (AAL) in dollars across multiple homes is needed to provide valuable information for stakeholder decision-making. This research develops a computational framework to evaluate AAL at the neighborhood level by owner/occupant type (i.e., homeowner, landlord, and tenant) for increasing first-floor height (FFH). The AAL values were calculated here by numerically integrating loss-exceedance probability distributions to represent economic annual flood risk to the building, contents, and use. A simple case study for a census block in Jefferson Parish, Louisiana, revealed that homeowners bear a mean AAL of $4,390 at the 100-year flood elevation (E ₁₀₀), compared with $2,960, and $1,590 for landlords and tenants, respectively, because the homeowner incurs losses to building, contents, and use, rather than only two of the three, as for the landlord and tenant. The results of this case study showed that increasing FFH reduces AAL proportionately for each owner/occupant type, and that two feet of additional elevation above E ₁₀₀ may provide the most economically advantageous benefit. The modeled results suggested that Hazus Multi-Hazard (Hazus-MH) output underestimates the AAL by 11% for building and 15% for contents. Application of this technique while partitioning the owner/occupant types will improve planning for improved resilience and assessment of impacts attributable to the costly flood hazard.

Keywords: Hazus Multi-Hazard (Hazus-MH); Louisiana; average annual loss (AAL); first-floor height (FFH); flood risk; natural hazard mitigation; neighborhood resilience; owner/occupant type.

Grants and funding

This research was funded by the USDA National Institute of Food and Agriculture, Hatch project LAB 94873, accession number 7008346, U.S. Department of Homeland Security (Award Number: 2015-ST-061-ND0001-01), the Louisiana Sea Grant College Program (Omnibus cycle 2020–2022; Award Number: NA18OAR4170098; Project Number: R/CH-03; Omnibus cycle 2022–2024; Award Number: NA22OAR4710105; Project Number: R/CH-05), the Gulf Research Program of the National Academies of Sciences, Engineering, and Medicine under the Grant Agreement number: 200010880, “The New First Line of Defense: Building Community Resilience through Residential Risk Disclosure,” and the U.S. Department of Housing and Urban Development (HUD; 2019–2022; Award No. H21679CA, Subaward No. S01227-1). The publication of this article is subsidized by the LSU Libraries Open Access Author Fund.