Category: Flooding

Our new paper on the socio-geographic patterns of rescue requests during Hurricane Harvey has been published in Findings

8/31/2022

Our paper on the socio-geographic patterns of rescue requests during Hurricane Harvey has been published in Findings. Below is the abstract:

"We analyze a public dataset of rescue requests for the Houston Metropolitan Area during Hurricane Harvey (2017) from the Red Cross. This dataset contains information including the location, gender, and emergency description in each requester’s report. We reveal the spatial distribution of the rescue requests and its relationship with indicators of the social, physical, and built environment. We show that the rescue request rates are significantly higher in regions with higher percentages of children, male population, population in poverty, or people with limited English, in addition to regions with higher inundation rate or worse traffic condition during Hurricane Harvey. The rescue request rate is found to be statistically uncorrelated with the percentage of flood hazard zone designated by the Federal Emergency Management Agency (FEMA)."

Figure 1.Spatial Distribution of Event-related Variables in Each Zip Code. a). Percentage of people who sought rescues during Harvey, b). Traffic index during Harvey, c). Inundation index during Harvey.

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Open PhD Position – coastal community resilience, risk perceptions, community engagement, Nature Based Solution

8/2/2022

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The Environmental Decision Making Lab at the Department of Geography of the University of Alabama seeks a geography PhD student to focus on coastal community resilience, risk perceptions, community engagement under the theme of Nature Based Solution (NBS). The broader research team is focused on developing actionable design guidance for NBS (i.e., wetland restoration) along the US Gulf Coast. Our highly interdisciplinary group includes social scientists, wetland ecologists, water resource engineers, and government agency partners. Our goal is to develop guidance for wetland restoration activities optimized to reduce flooding and increase coastal community resilience. To accomplish this goal, we will employ a combination of community engagement, wetland plant community characterization, and state-of-the-art hydrologic and hydraulic modeling.

The successful candidate will be expected to start in spring, 2023. The candidate will work closely with social scientists, wetland ecologists, and water resource engineers, and our government partners to develop, assess, and communicate NBS design alternatives by engaging stakeholders in a knowledge co-production fashion. The candidate will be expected to work with the team to develop a plan for stakeholder engagement meetings, organize and facilitate stakeholder engagement activities, collect the data from the meetings, analyze the data, and report findings in peer-reviewed manuscripts. Through this work, the candidate will also be expected to develop hypothesis driven research based on their interests.
The ideal candidate will have MS degrees in a relevant field (i.e., geography, urban and regional planning, environmental sociology, ecology, environmental science, or closely related field). The candidate should be excited about working on an interdisciplinary team; interacting with community partners, and conducting both basic and applied research. Further, experience with statistical analysis and programs (e.g., R, Stata, SPSS) and geographic information systems (e.g., ArcGIS, QGIS) are required. Experience with textual analysis programs (e.g., NVivo) is preferred but not required. Additionally, experience with scripting languages (e.g., R, Python, or Matlab) are preferred but not required.

For more information, please contact Dr. Wanyun Shao (wshao1@ua.edu)

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Our new paper on perceptions of sea level rise in Climatic Change

10/10/2020

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Our new paper on perceptions of sea level rise has been published in Climatic Change (Impact factor: 4.743). Below please find the abstract:
"Sea level rise (SLR) in the 21st century poses fundamental risks to coastal residents. The U.S. Gulf of Mexico Coast (Gulf Coast) is among the regions experiencing the most rapid relative SLR. Beyond its increasing exposure to SLR and related coastal flooding, the Gulf Coast is home to a large population and displays high social vulnerability. How the coastal population in this vulnerable region perceives the impending risks posed by SLR warrants further examination. Do coastal residents’ perceptions of SLR conform to the scientific projections? We adopt an integrative approach based on a 2019 survey merged with contextual data including percentage of population living within the Special Flood Hazard Area (SFHA) and social vulnerability at the county level, both of which are extracted from the Centers for Disease Control and Prevention. We find that public risk perceptions of sea level change are influenced by political predisposition, with Republicans being less likely than Democrats to expect SLR in the future. Moreover, SLR remains temporally distant issue among coastal residents. We then directly compare public expectations and scientific estimations of SLR in five states of the U.S. Gulf Coast region and find that coastal residents in states that have experienced faster SLR in the past are more optimistic about future SLR by underestimating its magnitude compared to those experiencing slower SLR. Moreover, we find that people likely conflate the severity with likelihood of SLR risk. The contextual force represented by percentage of population living within the SFHA designated by the Federal Emergency Management Agency (FEMA) can significantly influence individuals’ estimations of future SLR, with higher percentages leading to higher estimates. We suspect that the SFHA has become a powerful risk communication tool that influences coastal residents’ judgments about future risk.

Figure 3. Comparison of public estimation with scientific estimation of SLR at five locations in Texas, Louisiana, Mississippi and Alabama, Florida Panhandle, and Florida Peninsula along the U.S. Gulf Coast. Percentages assigned at lower level and upper level in each figures represent percentages of respondents who estimated future SLR to be lower than the 5th and higher than the 95th scientific estimates, respectively (Source: Shao et al. in press).

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Our new paper on polycentric governance in flood management

10/4/2020

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our new paper has been published in Climate Policy (impact factor: 5.085). Below please find the abstract:

"Floods increasingly threaten disadvantaged communities around the globe. When limited financial resources are available, nature-based and community-based incremental adaptation that codifies existing actions and behaviors can help protect people and assets through risk reduction management. These adaptation measures mainly rely on non-financial capital that can be appropriate alternatives when financial resources are limited, especially within the context of disadvantaged communities. There are, however, challenges in implementing such adaptation measures, including differential power relationships that might lead to misallocation of benefits. We propose a polycentric governance framework that can enhance stakeholder engagement and mobilize various forms of non-financial capital to trigger a web of incremental adaptation measures through four support mechanisms: technological investment, institutional enhancement, knowledge production, and environmental protection. We further discuss how various facilitating factors, including i) communication and transportation infrastructure, ii) flexible laws/regulations, iii) risk communication, and iv) environmental restoration, can increase the likelihood of success in application of the framework. A successful application of the proposed framework also necessitates development of a research agenda around suitable non-financial metrics for monitoring and evaluating the performance of the proposed strategies. In addition, learning from new developments in general societal protection and resilience in communities with relatively large financial capital and experiences of practicing polycentric governance in disadvantaged communities may facilitate the implementation of polycentric governance-based disaster risk reduction globally."

Figure 1: The proposed polycentric governance framework for incremental adaptation for disaster risk reduction. (Source: Moftakhari et al. in press)

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A Ph.D opportunity

10/1/2020

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My research group Environmental Decision Making at the Department of Geography at the University of Alabama is accepting applications for a Ph.D student with research assistantship, in social dimension of hazards in general and flood hazards in particular. The assistantship provides a stipend plus tuition remission.

The successful applicant will work with me and two research groups at the Department of Civil, Construction, and Environmental Engineering and will be involved in projects focused on human dimension of flood hazards.

Qualified candidates should have a Master’s degree in Geography, Environmental Studies/Sciences, Planning or a related discipline. Candidates should have a strong interest in the intersection of social and physical dimensions of hazards and be eager to work in an interdisciplinary environment. Experience in quantitative data analysis, survey design, geographic information systems (GIS) are desired. Strong oral and written communication skills are required.

For more information about this assistantship, please contact me at wshao1@ua.edu well in advance of February 15, 2021 (the application deadline). Please include a copy of your CV, unofficial academic transcripts, and a brief personal statement that highlights skills relevant to the position.

For more information about the department, please see https://geography.ua.edu/.

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Our new paper in Science of the Total Environment

7/19/2020

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Our new paper has been published in Science of the Total Environment (Impact Factor: 7.963). Below please find the abstract:

"Climate extremes will be intensified and become more frequent. One of the regions where this is the case is the U.S. Gulf coast region. This region is susceptible to the impacts of climate extremes. This region has recently experienced large amounts of economic damages caused by high-impact hurricanes and floods. Meanwhile, drought can also pose serious risks once it occurs. By using a 2019 U.S. Gulf Coast survey combined with Standard Precipitation Index, we closely examined retrospective and prospective evaluations of drought and flood among coastal residents. Drawing upon literature on human-environment system, we were interested in how the objective conditions of past drought and flood influenced individual’s perceptions of these hazards and how their retrospective evaluations were correlated with their prospective evaluations of future trends of these hazards. Coastal residents’ retrospective evaluations of past drought and flood were found to be influenced by historic objective conditions. Higher drought frequencies were found to increase the probability of perceiving increasing trend of drought number in the past. Higher flood frequencies were found to decrease the probability of perceiving increasing trend of flood number in the past. Higher intensities of drought and flood were found to increase the probabilities of perceiving increasing trends of drought duration and flood amount in the past. Coastal residents’ prospective evaluations of future drought and flood were found to be influenced by retrospective evaluations of these hazards, suggesting the temporal continuity in human judgement. Moreover, those who relied on a longer time span in reference to the future were found to be more likely to perceive increasing trends of drought and flood. We ended this paper by proposing a theoretical framework to guide future studies and discussing policy implications."

Core Figure - Figure 4. Retrospective evaluations of drought and flood risk and association with objective conditions (a) and their correlations with prospective evaluations of drought and flood risk (b). In (a), filled circles, circles with cross, empty circles depict the frequency, duration, intensity, respectively, of drought (red) and flood (blue). In (b) filled (empty) circles depict retrospective evaluations on past drought and flood numbers (past drought duration and past flood amount). The bars represent confidence intervals of all the estimated coefficients (Shao and Kam, 2020)

Graphic Abstract

Figure 2. Number of states under regional drought events (red) and regional pluvial flood events (blue) (Shao and Kam, 2020)

Figure 3: Monthly time series of the relative search activity indices on drought (a) and flood (b) between 2004 through 2018. Dark (light) lines depict the averages (maximum and minimum values) of the relative search activity indices over the five Gulf costal states (Shao and Kam, 2020)

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A new paper in Scientific Reports

12/29/2019

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In a new paper, we assessed the socio-economic vulnerability to flash floods across the contiguous U.S. This paper has been published in Scientific Reports (a Nature journal). For more information, below please find the abstract:

"Flash flood is among the most catastrophic natural hazards which causes disruption in the environment and societies. Flash flood is mainly initiated by intense rainfall, and due to its rapid onset (within six hours of rainfall), taking action for effective response is challenging. Building resilience to flash floods require understanding of the socio-economic characteristics of the societies and their vulnerability to these extreme events. This study provides a comprehensive assessment of socio-economic vulnerability to flash floods and investigates the main characteristics of flash flood hazard, i.e. frequency, duration, severity, and magnitude. A socio-economic vulnerability index is developed at the county level across the Contiguous United States (CONUS). For this purpose, an ensemble of social and economic variables from the US Census and the Bureau of Economic Analysis were analyzed. Then, the coincidence of socio-economic vulnerability and flash flood hazard were investigated to identify the critical and non-critical regions. Results show that the southwest U.S. experienced severe flash flooding with high magnitude, whereas the Northern Great Plains experience lower severity and frequency. Critical counties (high-vulnerable-hotspot) are mostly located in the southern and southwestern parts of the U.S. The majority of counties in the Northern Great Plains indicate a non-critical status."

Figure 7. Flash flood hazard characteristics converted from gauge station to the county-scale (Khajehei et al. 2020)

Figure 8. Maps of the counties where flashflood extremes coincide with socio-economic vulnerability extremes (Khajehei et al. 2020)

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A new paper in Disasters

6/28/2019

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Our new paper was published in Disasters (impact factor: 1.797). Here is the abstract:

"It is of significance to assess and depict community vulnerability to floods and hurricanes. Over the past several decades, flooding and hurricanes have affected millions of people and caused massive economic losses. Despite efforts to reduce risks, these natural hazards remain to be a considerable challenge to coastal communities. In this paper, Geographic Information Systems (GIS) methods are used to analyze coastal communities’ vulnerability to hurricanes and flooding along the U.S. Gulf coast, which is prone to these two hazards. Specifically, two types of quantitative indicators are developed: exposure to hurricanes and flooding, based on data from multiple sources such as National Climate Data Center and National Flood Insurance Program among others, and a social vulnerability index, constructed on census data at census tract level. These indices are combined to depict the spatial patterns of overall community vulnerability to flooding and hurricane hazards along the U.S. Gulf Coast. Results of this study can potentially inform disaster management agencies, county governments and municipalities of areas with heightened community vulnerabilities. The demonstration of geographic distribution of community vulnerability can assist decision makers in prioritizing to‐do items and designing policies/plans for more effective allocation of resources. We end this paper by discussing the limitations to the present study and the practical implications of the assessment."

The following two figures are from this article (Shao et al. forthcoming).

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A new paper in Environmental Research Letters

4/15/2019

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Our paper on public support for flood mitigation was just published on Environmental Research Letters (impact factor: 6.192). Here is the abstract:

"What is the decision-making mechanism people rely upon to mitigate flood risk? Applying Bayesian Network modelling to a comprehensive survey dataset for the U.S. Gulf Coast, we find that the overall support for flood mitigation can be inferred from flood insurance purchase behavior (i.e., without insurance vs. with insurance purchased mandatorily, voluntarily, or both). Therefore, we propose a theoretical decision-making mechanism composed of two dimensions including informed flood risk and sense of insecurity. The informed flood risk is the primary determinant on one's overall support for flood mitigation. Risk mitigation decisions are largely contingent on the level of risk that is effectively conveyed to individuals. Additionally, sense of insecurity plays a moderate role in determining individuals' overall support for flood mitigation. The sense of insecurity can move people toward overall support for mitigation, but the effect is not as large as the informed risk. Results of this study have fundamental policy implications. The flood risk informed by Federal Emergency Management Agency's flood maps not only provides the compulsory basis for flood insurance purchase but also determines individuals' overall support for flood mitigation. Flood map inaccuracy can immensely mislead individuals' overall risk mitigation decision. Meanwhile, this flood risk mitigation decision-making mechanism inferred from a survey data in the U.S. Gulf Coast needs to be tested and validated elsewhere."

In this paper, we proposed a flood mitigation decision-making mechanism (please see below). One implication of this study is that "the importance of risk information in overall flood mitigation decisions. Although the flood premiums do not reflect real risks due to discounts, flood hazard zones have effectively conveyed the risk to homeowners. Risk signals can thus be delivered to homeowners through various means."

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Our new paper on flood perceptions

12/21/2018

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Our new paper on how physical geography influences perceptions of flooding just got published online in the Journal of Hydrology (impact factor: 4.405). Here is the abstract of this paper:

"How does physical history of flood-related hazards affect individuals’ perceptions? The present study represents a unique effort to understand perceptions of flood hazards in light of the geographic background. Situated in Alabama, the United States, the cities of Mobile and Huntsville display two different physical geographic contexts. Despite one being a coastal city (Mobile) and the other being an inland city, both are similarly vulnerable to flooding. We first present results of historical analyses of heavy precipitation in both cities and analysis of storm surge history in the city of Mobile. We then report results of both descriptive statistical and inferential statistical analyses based on a two-city residents’ survey that was conducted in the spring of 2016. We find that residents in both cities are able to connect the particular natural hazard of flooding with their physical environments. Residents in both cities are influenced by their perceptions of precipitation when making assessments of flooding. Despite the fact that Huntsville has not experienced heavy precipitation events as much as Mobile in recent history, residents of Huntsville tend to link heavy rainfall – the most frequent cause of flooding in that city, with flooding. In contrast, residents of Mobile tend to link hurricanes, more particularly hurricane number, with flooding. These results show that people are attuned to their physical environments and take into consideration their personal observations when forming perceptions of natural hazards. More studies need to be conducted to further investigate the dynamics of physical exposure to hazards and risk perceptions in other geographic areas."

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Our new paper on the socio-geographic patterns of rescue requests during Hurricane Harvey has been published in Findings

Open PhD Position – coastal community resilience, risk perceptions, community engagement, Nature Based Solution

Our new paper on perceptions of sea level rise in Climatic Change

Our new paper on polycentric governance in flood management

A Ph.D opportunity

Our new paper in Science of the Total Environment

A new paper in Scientific Reports

A new paper in Disasters

A new paper in Environmental Research Letters

Our new paper on flood perceptions

Wanyun Shao, Ph.D

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