Assessing population exposure to coastal flooding due to sea level rise

Hauer, Mathew; Hardy, Dean; Kulp, Scott; Mueller, Valerie; Wrathall, David; Clark, Peter U.

doi:10.1038/s41467-021-27260-1

Cited by 98 publications

(25 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Second, we assume no adaptation—future flood thresholds are the same as present‐day flood thresholds (Ghanbari et al., 2019; Hague et al., 2020; Sweet et al., 2018; Thompson et al., 2021). Finally, we assume that SLR manifests as an increase in tide heights, increasing the water levels about which tides rise and fall, but not the heights of skew surges (Dahl et al., 2017; Dusek et al., 2022; Hauer et al., 2021; Ray & Foster, 2016; Sweet et al., 2018). In aggregate, these three assumptions mean freeboard only changes in response to SLR (via increases in tide heights) with TR and ESS values constant.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

The Global Drivers of Chronic Coastal Flood Hazards Under Sea‐Level Rise

Hague,

McGregor,

Jones

et al. 2023

Earth's Future

View full text Add to dashboard Cite

We present the first global estimates of annual average exceedances of contemporary minor, moderate, and major flood levels under sea‐level rise (SLR). Applying established methods, we show that minor flooding will occur most days worldwide under 0.7 m global SLR. Moderate flooding occurs at the same frequency under 1.0 m SLR. Local and regional differences in flood threshold elevations, tidal ranges, and non‐tidal variability lead to differences in the SLR required for this chronic flooding to emerge. Lower flood thresholds, smaller tidal ranges, and larger extreme skew surges mean chronic flooding can emerge with less SLR. We discuss several implications of these findings for coastal flood hazard assessments. First, tide‐driven water level variability dominates weather‐driven water level variability when determining locations' propensities for frequent and chronic flooding under SLR. Second, centimeter‐accurate flood threshold information is necessary to accurately estimate present and future flood hazards. Third, locations with the most frequent floods at present may not be those that have the most frequent floods under SLR. We develop the Rapid Assessment Framework for Frequent Flood Transitions under SLR (RAFFFTS) to apply these findings to locations not previously considered in global coastal flood hazard studies. RAFFFTS can robustly identify potential future tidal flooding hotspots using only 1‐year observational records. We anticipate RAFFFTS will be a valuable tool for identifying locations at risk of chronic flooding under SLR, complementing existing tools for identifying changes in less frequent episodic floods.

show abstract

Section: Methodsmentioning

confidence: 99%

“…Hence, we do not consider these processes further here, focusing on so‐called “still” water levels. This follows the approach of many other global and national coastal flood hazard studies (Hauer et al., 2021; Kulp & Strauss, 2019; Rasmussen et al., 2018).…”

Section: Introductionmentioning

confidence: 99%

The Global Drivers of Chronic Coastal Flood Hazards Under Sea‐Level Rise

Hague,

McGregor,

Jones

et al. 2023

Earth's Future

View full text Add to dashboard Cite

show abstract

“…This assumption is often called 'uniform population density' . Some [11,27,30] operationalized this assumption by using (or creating) a raster layer of population density whose grid matched the elevation data, based on the assumption that the population within a given census block is uniformly distributed throughout the block. By contrast, this study (like some older studies [12,29]) defines each hazard zone as a set of polygons representing the portions of census blocks within the hazard zone.…”

Section: Interpolating Vulnerability Data To Match the Hazard Zonementioning

confidence: 99%

Population in floodplains or close to sea level increased in US but declined in some counties—especially among Black residents

Titus

2023

Environ. Res. Lett.

View full text Add to dashboard Cite

Previous studies estimating US population vulnerable to climate change have assumed that population is uniformly distributed within the geographical unit of analysis, typically a census block. That assumption overstates vulnerable population in places where people have avoided the most hazardous areas. After using independent samples of housing location and building footprints to validate a revised approach, this letter estimates the US population close to sea level and in floodplains based on the assumption that population in a hazard zone is proportional to the fraction of buildings in the hazard zone, for the period 1990–2020. The building-based assumption reduces population estimates about 30%. Over the 30-year period, the US population below 1 m increased 14%–18% from 1.85 (±0.19) million in 1990 to 2.2 (±0.25) million; population below 3 m increased 31%. Sea level rise accounts for 75% of the increase in population below 1 m, but only 14% of the increase below 3 m. Nevertheless, in 21 counties, net emigration from land below 1 m was greater than 1% of county population. Although this emigration was particularly great in the 2000s after Hurricane Katrina, it totaled 170 000 for the entire 30-year period. Similarly, the US population of inland 100-year floodplains increased 7%, but several hundred counties saw a steady emigration throughout the 30-year period which totaled about 240 000. Black residents accounted for 19% of the population below 1 m but only 12% of the nation’s population in 2020, meaning that Black residents were 63% more likely to live below 1 m than the general population nationwide. This disproportionality is more attributable to high Black populations in the most vulnerable localities (especially New Orleans) than to historic segregation. Black people also are almost five times as likely to have emigrated from land below 1 m than the general population since 1990.

show abstract

“…Coastal flooding exacerbated by climate change driven sea level rise in the 21 st Century (21C) is recognized as a major existential threat that will affect the livelihoods of more than 1 billion people globally [1,2]. This includes between a quarter to more than half of all people living in Pacific Islands [3].…”

Section: Introductionmentioning

confidence: 99%

Sea-Level Rise Effects on Changing Hazard Exposure to Far-Field Tsunamis in a Volcanic Pacific Island

Welsh¹,

Williams²,

Bosserelle³

et al. 2023

Preprint

View full text Add to dashboard Cite

Coastal flooding exacerbated by climate change is recognised as a major global threat which is expected to impact more than a quarter of people currently residing in Pacific Islands countries. While most research in the last decade has focused on understanding the dynamics and impacts of future coastal flooding from extreme sea levels, relative sea level rise (RSLR) effects on tsunami hazards are not well understood. Far-field or distant-sourced tsunamis tend to have relatively lower impacts in Pacific Island states compared with locally sourced events, but there is limited understanding on how the impact of far-field tsunamis changes over time due to RSLR. Using the hydrodynamics software BG-Flood, we modelled the Tōhoku tsunami from propagation to inundation in Samoa under incremental SLR to examine the effects that RSLR has on changing the exposure of the built environment (e.g., buildings) to a far-field tsunami. Outputs of maximum tsunami inundation and flow depth intensities which incorporate incremental SLR were then combined with digital representations of buildings and depth-damage functions in the RiskScape multi-hazard risk modelling software to assess the changes in building exposure over time. Results indicate that present day buildings exposure in Samoa to a Tōhoku-oki type far-field tsunami will increase by approx. 600% with 1 m RSLR by 2080–2130, and approx. 2,350% with 2 m RSLR by 2130–2140. These findings provide a useful baseline for tsunami hazard risk assessment under changing sea level conditions in analogous island environments.

show abstract

Assessing population exposure to coastal flooding due to sea level rise

Cited by 98 publications

References 53 publications

The Global Drivers of Chronic Coastal Flood Hazards Under Sea‐Level Rise

The Global Drivers of Chronic Coastal Flood Hazards Under Sea‐Level Rise

Population in floodplains or close to sea level increased in US but declined in some counties—especially among Black residents

Sea-Level Rise Effects on Changing Hazard Exposure to Far-Field Tsunamis in a Volcanic Pacific Island

Contact Info

Product

Resources

About