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USGS Coastal Storm Modeling System “CoSMoS”

Funded by the

USGS Coastal & Marine Hazards & Resources Program

USGS Pacific Islands Climate Adaptation Science Center

DOD Strategic Environmental Research and Development Program

Consistent National-scale Projections of Future Coastal Flooding due to Climate Change and Sea-level Rise to Evaluate Risk and Guide Adaptation

Patrick Barnard¹, Olivia Cheriton¹, Jeff Danielson², Anita Englestad¹, Li Erikson¹, Amy Foxgrover¹, Camilla Gaido³, Eric Grossman¹, Jeanne Jones⁴, Maya Hayden¹, Dan Hoover¹, Robert McCall⁵, Kees Nederhoff⁶, Alex Nereson¹, Andrea O’Neill¹, Maarten van Ormondt⁵, Kai Parker¹, Borja Reguero³, Manoocher Shirzei⁷, Curt Storlazzi¹, Peter Swarzenski¹, Jennifer Thomas¹, Sean Vitousek¹ and Nate Wood⁴

¹United States Geological Survey, Pacific Coastal and Marine Science Center

²United States Geological Survey, Earth Resources Observation and Science (EROS) Center

³University of California, Santa Cruz

⁴United States Geological Survey, Western Geographic Science Center

⁵Deltares, The Netherlands

⁶Deltares USA

⁷Virginia Tech

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Visualizations

Communities, regional governments, and Federal agencies are already dealing with coastal hazards -- and SLR will increase risks…

Impacts to operations, infrastructure, contaminants, freshwater availability, threatened & endangered species, cultural resources, etc.

Problem

Puget Sound, WA, December 17, 2012 (C. Mass)

Miami, FL

Globally, 300 million people and $14 trillion in assets could be exposed to SLR- and storm-driven coastal flooding by 2100

In California, over 600,000 people and $200 billion in property at risk by 2100 (6% of GDP)

Latest guidance from the Interagency SLR Task Force*

25-30 cm (0.8-1.0 ft) SLR by 2050 (equals rise from last 100 years)

60-220 cm (2-7 ft) SLR by 2100

SLR will likely cause ‘once-in-a-lifetime’ coastal flooding events to occur annually by 2050, and every day by 2100

When considering storms and coastal change, ~3 times more people would be at risk

By the end of the 21^st century, coarse resolution models suggest that up to 300 million people and $14 trillion in assets could be exposed to SLR- and storm-driven coastal flooding (Kirezci et al., 2020). Kirezci, E., Young, I.R., Ranasinghe, R. et al. Projections of global-scale extreme sea levels and resulting episodic coastal flooding over the 21st Century. Sci Rep 10, 11629 (2020). https://doi.org/10.1038/s41598-020-67736-6

Pac Institute (2009) Source of 500,000 people and $100 billion in damages ($62 billion in SF Bay!!!) do to SLR and historical 100-year flood level (from FEMA base flood elevations (BFEs)), but does NOT include:

-river discharge

-change in storm patterns/flood levels

-recent LIDAR

$2.6 billion in property damages in 1997-98, $2 billion in crops, $25 billion total to US economy

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Visualizations

https://sealevel.nasa.gov/task-force-scenario-tool?psmsl_id=127

Interagency SLR Task Force Sea Level Scenarios

Problem

- SLR guidance is ever-evolving

- Agencies/users have different planning needs

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Goal

Develop 1- (annual) , 20-, and 100-year storm return period coastal flooding projections

……at management-scale (10 m²/32 ft²) resolution for:

0.00, +0.25, +0.50, +1.00, +1.50, +2.00, and +3.00 meters of sea-level rise

….using robust, consistent, accurate methodology

Provide science to help guide management actions to climate change and sea-level rise

Scenarios line up with the Interagency SLR Task Force, which DOD is a member

Scenarios are “timeless”: Can adapt to various planning horizons and guiding information (e.g., IPCC-AR5 / AR6, NCA-4, Kopp et al. (2017; 2023+), NCA-5, etc...)

Goal

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Visualizations

CoSMoS +0.25 m

CoSMoS +0.50 m

CoSMoS +1.00 m

CoSMoS +1.50 m

CoSMoS +2.00 m

CoSMoS +3.00 m

CoSMoS is intended to help plan for sea-level rise when it matters most….during storms and extreme events

Goal

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Methods

Unique approach to capture dynamic impacts & support a Common Operational Picture

Methods overview

Explicit, high-resolution, dynamic simulations of waves, currents, storm surge, and the resulting coastal flooding

Considers the future evolution of storm patterns based on the latest IPCC-AR6 Global Climate Models

Uses state-of-the-science projections of winds and waves

Extensively tested, calibrated, and validated with local historic data

Flood projections are based on dynamic wave setup

All storm scenarios available for a range of SLR scenarios, providing flexible suite of projections for any planning horizon

Consistent products across all regions

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Methods

Modeling framework

Barnard, P.L. et al.., 2019. Scientific Reports, Volume 9, Article #4309, 13 pp., http://dx.doi.org/10.1038/s41598-019-40742-z

XBeach,

SFINCS

GTSM, WaveWatch III

D-Flow FM,

Delft3D Flow+Wave,

SWAN

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Methods

Future Forcing

IPCC-AR6 (2021) CMIP6 Global Climate Models from HighResMIP Project

Finer spatial resolution

better resolves

tropical cyclones

GFDL-CM4C192 (US)
CMCC-CM2-VHR4 (IT)
HadGEM3-GC-31-HM (UK)
HadGEM3-GC-31-HM-SST (UK)

Methods

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Methods

Future Tide and Storm Surge

Global Tide and Surge Model (GTSM)

(Muis et al. 2016; Dullaart et al., 2019)

1979-2019:

ERA5 reanalysis used for validation

2015-2050/2100:

CMIP6 GCMs

Methods

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Methods

WaveWatchIII (WW3)

(Tolman 1997, 1999, 2009)

1979-2019:

WW3 hindcast phase-2 used for validation

2020-2050:

CMIP6 GCMs

~55 km resolution

*** Consistent model ensemble for surges and waves ***

(first in the world for CMIP6)

~18 km resolution

Future Waves

Methods

Erikson, L.H., Herdman, L., Flanary, C., Engelstad, A., Pusuluri, P., Barnard, P.L., Storlazzi, C.D., Beck, M., Reguero, B., Parker, K., 2022, Ocean wave time-series data simulated with a global-scale numerical wave model under the influence of projected CMIP6 wind and sea ice fields: U.S. Geological Survey data release, https://doi.org/10.5066/P9KR0RFM.

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Methods

Future Waves

SWAN

(Booij and others, 1999; Ris and others, 1999)

200 m² resolution

72 directional bins

999 sea states (H_s, T_p, W_dir)

Methods

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Methods

Storms

Methods

Erikson, L.H., et al., 2018. Identification of storm events and contiguous coastal sections for deterministic modeling of extreme coastal flood events in response to climate change, Coastal Eng., 140, https://doi.org/10.1016/j.coastaleng.2018.08.003.

Representative events for each R.I.

Storm 1

Storm 2

Storm n

…

Resulting

hazard

D-Flow FM,

Delft3D,

XBeach,

SFINCS

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Methods

Future Flooding

Water depth for 100-year R.I. storm and SLR +1.00 m

Methods

Flood extent for progressing R.I.

SLR: 1.0 m

Water depth for 50-yr R.I. storm and SLR 1.0 m

Flood extent for progressing SLR

Storm: 100-yr R.I.

San Diego, CA

Charleston, SC

Barnard, P.L. et al., 2018. Coastal Storm Modeling System (CoSMoS) for Southern California, v3.0, Phase 2 (ver. 1b, October 2016): U.S. Geological Survey data release, https://doi.org/10.5066/F7T151Q4.

Barnard, P.L. et al., 2023. Future coastal hazards along the U.S. North and South Carolina coasts: U.S. Geological Survey data release: https://doi.org/10.5066/P9W91314

Storlazzi, C.D., Reguero, B.G, Gaido, C.L., Alkins, K.C., Lowrie, C., Nederhoff, K.M., Erikson, L.H., O’Neill, A.C., and Beck, M.W., 2024. Forecasting Storm-Induced Coastal Flooding for 21st Century Sea-Level Rise Scenarios in the Hawaiian, Mariana, and American Samoan Islands. U.S. Geological Survey Data Report

Kailua and Waimanalo, O'ahu

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Visualizations

Web tools and GIS data of projections for

21 SLR + storm scenarios

Meters

0.25

0.50

1.00

1.50

2.00

3.00

Feet

0.8

1.6

3.3

4.9

6.6

9.8

Sea Level Rise

Flood extent
Flood depth
Wave heights
Socio-economic exposure

PRODUCTS**

Annual (1-yr)

20-year

100-year

Storm Frequency

Core Products

Web Tools

ACCESS:

GIS

data

Web

tools

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Visualizations

20-year storm

+1.00 m SLR

20-year storm

0.00 m SLR

20-year storm

+0.25 m SLR

20-year storm

+0.50 m SLR

20-year storm

+1.00 m SLR

Example flood depth maps for Marine Corps Base Hawaii

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Visualizations

20-year storm

0.00 m SLR

20-year storm

+0.25 m SLR

20-year storm

+0.50 m SLR

20-year storm

+1.00 m SLR

Example flood depth maps for Naval Base Guam

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Visualizations

20-year storm

+1.00 m SLR

20-year storm

+1.00 m SLR

Example flood depth maps for Hickam Air Force Base and Naval Base Pearl Harbor

20-year storm

0.00 m SLR

20-year storm

+0.25 m SLR

20-year storm

+0.50 m SLR

20-year storm

+1.00 m SLR

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Visualizations

What can be done

We have the ability to generate a range of potentially useful products to support design and siting of new development.

If there is information on sensitivity, we can assess the vulnerability of existing development and help identify adaptation pathways.

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Visualizations

What can be done

Thorough sensitivity, vulnerability, and risk assessments

Bick, I. A., et al., 2021. Rising seas, rising inequity? Communities at risk in the San Francisco Bay Area and implications for adaptation policy. Earth's Future, 9, https://doi.org/10.1029/2020EF001963

Marra et al., 2023. Advancing Best Practices for the Analysis of the Vulnerability of Military Installations in the Pacific Basin to Coastal Flooding under a Changing Climate – RC-2644: Final Report for the U.S. Department of Defense Strategic Environmental Research and Development Program. 543 pp. https://serdp-estcp.org/projects/details/53e39247-037c-4319-850d-cb3d796f25f5

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Visualizations

Scope & Timeline

Guam

Commonwealth of the Northern Mariana Islands

Hawai’i

American Samoa

South/Central California

Northern

California

Pacific Northwest

Puget Sound

2025

2024

2026

Alaska

2026

U.S. Southeast

U.S. Northeast

Gulf Coast

Florida

Puerto Rico

U.S. Virgin Islands

NORTH PACIFIC OCEAN

SOUTH PACIFIC OCEAN

SOUTH AMERICA

NORTH AMERICA

ASIA

PROJECT STATUS

completed

in progress

future priority

DOD Coastal Installations

hazard products available/forthcoming

outside completed/ forthcoming hazard product areas

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Methods

Global Future Forcing

IPCC-AR6 (2021) CMIP6 Global Climate Models from HighResMIP Project

Finer spatial resolution better

Resolves tropical cyclones

Global wave model
Global tide and surge model

Can support DoD interests globally

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Provide consistent, sound,

cutting-edge science to

reduce risk,

increase resilience, and

better direct adaptation efforts

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Thank you!

Li Erikson

CoSMoS Technical Director for Modeling