U.S. Coastal Flood Insurance, Risk Perception, and Sea-Level Rise: A Perspective

Abstract. Coastal managers face the task of assessing and managing flood risk. This requires knowledge of the area of land, the number of people, properties and other infrastructure potentially affected by floods. Such analyses are usually static; i.e. they only consider a snapshot of the current situation. This misses the opportunity to learn about the role of key drivers of historical changes in flood risk, such as development and population rise in the coastal flood plain, as well as sea-level rise. In this paper, we develop and apply a method to analyse the temporal evolution of residential population exposure to coastal flooding. It uses readily available data in a GIS environment. We examine how population and sea-level change have modified exposure over two centuries in two neighbouring coastal sites: Portsea and Hayling Islands on the UK south coast. The analysis shows that flood exposure changes as a result of increases in population, changes in coastal population density and sea level rise. The results indicate that to date, population change is the dominant driver of the increase in exposure to flooding in the study sites, but climate change may outweigh this in the future. A full analysis of changing flood risk is not possible as data on historic defences and wider vulnerability are not available. Hence, the historic evolution of flood exposure is as close as we can get to a historic evolution of flood risk. The method is applicable anywhere that suitable floodplain geometry, sea level and population data sets are available and could be widely applied, and will help inform coastal managers of the time evolution in coastal flood drivers.

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Sea Level Rise Maps: How Individual Differences Complicate the Cartographic Communication of an Uncertain Climate Change Hazard

Cartographic Perspectives ◽

10.14714/cp77.1235 ◽

2014 ◽

pp. 17-32 ◽

Cited By ~ 9

Author(s):

David P Retchless

Keyword(s):

Climate Change ◽

Individual Differences ◽

Risk Perception ◽

Sea Level Rise ◽

Sea Level ◽

Final Section ◽

Spatial Coverage ◽

Online Maps ◽

And Sea Level

Interactive, online maps of sea level rise have great potential for communicating climate change, as evidenced by both their popularity and likely ability to combat discounting of climate change hazards. However, little is known about how different audiences will interpret the significant uncertainties—including those related to the amount, timing, and spatial coverage of sea level rise flooding—communicated on many of these maps. A review of the risk perception literature presents three situations where different aspects of uncertainty have been suggested to dictate (or at least strongly encourage) adaptive or mitigative action in the context of sea level rise or similarly uncertain hazards, then problematizes these accounts by showing how context and personal differences mediate (and in some cases reverse) these expected relationships. A final section offers preliminary reflections on the implications for the cartographic communication of climate change and sea level rise uncertainty.

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ASSESSING NON-LINEAR RESPONSE IN EXTREME COASTAL WATER LEVELS

Coastal Engineering Proceedings ◽

10.9753/icce.v36.risk.62 ◽

2018 ◽

pp. 62

Author(s):

Betsy Hicks ◽

Emily Dhingra ◽

Brian Batten ◽

Alaurah Moss ◽

Tucker Mahoney ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Water Levels ◽

Coastal Hazards ◽

Flood Insurance ◽

Flood Hazards ◽

Change Analysis ◽

Approximate Methods ◽

Coastal Flood ◽

Non Linear

Rising sea levels and the resultant amplification of flood frequencies and magnitude has the potential to significantly change coastal flood hazards over the coming century. The Federal Emergency Management Agency (FEMA) has recognized the potential future implications of Sea Level Rise (SLR) on coastal hazards and flood insurance. However, at present, FEMA does not incorporate future conditions information in to their regulatory or non-regulatory products in the framework of their National Flood Insurance Program. Many other programs that create products to support risk recognition and resilient planning are based on â€œbathtubâ€ approaches (for example NOAAâ€™s Sea Level Rise Viewer: https://coast.noaa.gov /digitalcoast/tools/slr). In order to better understand non-linear changes in coastal flood hazards, due to increased water depth and wave heights, or in the surge propagation pathway, FEMA has funded a series of pilot studies. For this study an end-of-the-century SLR condition has been imposed on storm surge simulations in West Florida to gain further understanding into how SLR may modify surge and wave effects, as well as potential techniques for approximating these via efficient approximate methods. Both the detailed nonlinear methods and approximate linear approaches for developing SLR advisory information will be evaluated and compared for this study. A second, mid-century SLR condition was utilized for a shoreline change analysis to evaluate how recession due to SLR may affect coastal flood hazards.

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Estimating the long-term historic evolution of exposure to flooding of coastal populations

Natural Hazards and Earth System Sciences Discussions ◽

10.5194/nhessd-3-1681-2015 ◽

2015 ◽

Vol 3 (2) ◽

pp. 1681-1715 ◽

Cited By ~ 6

Author(s):

A. J. Stevens ◽

D. Clarke ◽

R. J. Nicholls ◽

M. P. Wadey

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Flood Risk ◽

Population Change ◽

Opportunity To Learn ◽

Flood Plain ◽

Population Exposure ◽

Coastal Flood ◽

Flood Exposure ◽

And Sea Level

Abstract. Coastal managers face the task of assessing and managing flood risk. This requires knowledge of the area of land, the number of people, properties and other infrastructure potentially affected by floods. Such analyses are usually static; i.e. they only consider a snapshot of the current situation. This misses the opportunity to learn about the role of key drivers of historical changes in flood risk, such as development and population rise in the coastal flood plain and sea-level rise. In this paper, we develop and apply a method to analyse the temporal evolution of residential population exposure to coastal flooding. It uses readily available data in a GIS environment. We examine how population and sea level change modify exposure over two centuries in two neighbouring coastal sites: Portsea and Hayling Islands on the UK south coast. The analysis shows that flood exposure changes as a result of increases in population, changes in coastal population density and sea level rise. The results indicate that to date, population change is the dominant driver of the increase in exposure to flooding in the study sites, but climate change may outweigh this in the future. A full analysis of flood risk is not possible as data on historic defences and wider vulnerability are not available. Hence, the historic evolution of flood exposure is as close as we can get to a historic evolution of flood risk. The method is applicable anywhere that suitable floodplain geometry, sea level and population datasets are available and could be widely applied, and will help inform coastal managers of the time evolution in coastal flood drivers.

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An integrated framework of coastal flood modelling under the failures of sea dikes: a case study in Shanghai

Natural Hazards ◽

10.1007/s11069-021-04853-z ◽

2021 ◽

Author(s):

Qian Ke ◽

Jiangshan Yin ◽

Jeremy D. Bricker ◽

Nicholas Savage ◽

Erasmo Buonomo ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Flood Hazard ◽

Discharge Rate ◽

Coastal Flooding ◽

Water Volume ◽

Coastal Flood ◽

Sea Dikes ◽

And Sea Level

AbstractClimate change leads to sea level rise worldwide, as well as increases in the intensity and frequency of tropical cyclones (TCs). Storm surge induced by TC’s, together with spring tides, threatens to cause failure of flood defenses, resulting in massive flooding in low-lying coastal areas. However, limited research has been done on the combined effects of the increasing intensity of TCs and sea level rise on the characteristics of coastal flooding due to the failure of sea dikes. This paper investigates the spatial variation of coastal flooding due to the failure of sea dikes subject to past and future TC climatology and sea level rise, via a case study of a low-lying deltaic city- Shanghai, China. Using a hydrodynamic model and a spectral wave model, storm tide and wave parameters were calculated as input for an empirical model of overtopping discharge rate. The results show that the change of storm climatology together with relative sea level rise (RSLR) largely exacerbates the coastal hazard for Shanghai in the future, in which RSLR is likely to have a larger effect than the TC climatology change on future coastal flooding in Shanghai. In addition, the coastal flood hazard will increase to a large extent in terms of the flood water volume for each corresponding given return period. The approach developed in this paper can also be utilized to investigate future flood risk for other low-lying coastal regions.

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