Dissertation
Flood loss and social vulnerability in the US and pathways to unmet need reduction
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Summer 2023
DOI: 10.25820/etd.006955
Abstract
Persistent changes in land use, coupled with changes in hydrology, have significantly increased flood risk in the US. Traditional flood risk assessments focus on structural vulnerability and risk, giving limited attention to agricultural risk and social vulnerability. The absence of agricultural flood risk assessment at the national scale impedes understanding of the magnitude of flood impacts. Social vulnerability to floods is often studied by applying generic social vulnerability indicators across different types of flood impacts. However, there is still limited understanding of specific groups of the population that are most vulnerable to flood impacts. The characteristics of vulnerable populations can vary significantly based on the type of flood loss. On a local scale, flood mitigation measures largely focus on structural interventions, such as floodproofing. There is inadequate attention to non-physical needs such as health, social, and economic needs, which if unmet, reduce mitigation effectiveness.
The dissertation employs three studies to improve the understanding of flood risk and social vulnerability in the US. The first study uses flood loss estimation modeling to calculate the average annual loss for agriculture in the US. This study incorporates a broader set of contributing factors than employed in previous studies of agricultural flood loss. The second study tests the relationship between flood loss and social vulnerability using spatial regression models for structural and agricultural flood loss at a national scale. The third study identifies the social vulnerability pathways to the reduction of unmet needs during household flood mitigation using Qualitative Comparative Analysis methodology.
The estimated average annualized loss in the contiguous US is $546.84 million, with higher losses concentrated in the corn and soybean belt of the Midwest and Mississippi River Basin. Spatial analysis of social vulnerability and flood loss identified that for higher structural losses, the indicators of median house value, unoccupied housing units, and renter populations are the most explanatory. Meanwhile, for agricultural losses, employment in extractive industries, Asian populations, and civilian unemployment were the most explanatory factors. At the local scale, within a cohort of socially vulnerable households, those with fewer social vulnerability characteristics had the strongest causal pathways to successful reduction of unmet health and social needs. Collectively, the findings from this dissertation help inform the development of more equitable and effective flood mitigation.
Details
- Title: Subtitle
- Flood loss and social vulnerability in the US and pathways to unmet need reduction
- Creators
- Md Asif Rahman
- Contributors
- Eric Tate (Advisor)Margaret Carrel (Committee Member)Caglar Koylu (Committee Member)Silvia Secchi (Committee Member)Antonio Arenas Amado (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Geography
- Date degree season
- Summer 2023
- DOI
- 10.25820/etd.006955
- Publisher
- University of Iowa
- Number of pages
- x, 122 pages
- Copyright
- Copyright 2023 Md Asif Rahman
- Language
- English
- Date submitted
- 07/25/2023
- Description illustrations
- illustrations, tables, maps, graphs
- Description bibliographic
- Includes bibliographical references (pages 107-122).
- Public Abstract (ETD)
- The impact of flooding in the US has increased over the last few decades, and due to climate change, it will continue to affect more people and communities. To reduce the possibility of further impact, we need to understand which assets, such as crops, and which groups of the population will suffer the most.
In my dissertation, I calculated the potential annual loss of agriculture from flood events for the contiguous US. I also outlined which areas in the country have the highest and lowest losses. Social vulnerability refers to the conditions of individuals or communities that make them more susceptible to hazard impact. In my second study, I examined how different groups of socially vulnerable populations are influenced by agricultural and building flood loss. Finally, I identified which social and economic characteristics of flood-affected households most influence the efforts to reduce unmet needs.
The results indicate that flood-related agriculture losses are concentrated primarily in the corn and soybean belt of the US Midwest and Mississippi River Basin, with an expected annual loss of approximately $546 million. In areas with higher building losses, housing value, unoccupied housing units, and renter population are the most explanatory factors. For areas with higher agricultural losses, the most explanatory factors are employment in extractive industries, Asian populations, and civilian unemployment. Finally, among a group of flood-affected and socially vulnerable households, those with fewer social vulnerability attributes had the strongest causal pathways to the reduction of health and social unmet needs. In summary, the findings of this dissertation can help develop better approaches to mitigate the severity of flood impacts.
- Academic Unit
- Geographical and Sustainability Sciences
- Record Identifier
- 9984454741702771
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