Streaming Media

Presentation Abstract

The U.S. Geological Survey Coastal Storm Modeling System (CoSMoS) is being developed for the Salish Sea to evaluate flood hazards at a scale of 1 m to support coastal planning into the next century. CoSMoS computes extreme water levels and flooding accounting for projected sea level rise and climate change effects on river floods and storms. Modeled tides and storm surge show a mean absolute error of 10 cm across NOAA and USGS tide gages over the hindcast period 2018-2019. Model forcings deconstructed over a 1985-2015 hindcast indicate that storm surge inside Puget Sound is driven primarily by atmospheric pressure anomalies (up to 45 cm), outer shelf wind and current dynamics (up to 45 cm), large-scale North Pacific Ocean dynamics and interannual phenomena like the El Niño-Southern Oscillation (up to 20 cm), and wind setup generated within the Salish Sea (up to 20 cm). Future conditions are evaluated with spatiotemporally varying fields derived from dynamically-downscaled global climate models at 12 km spatial and hourly temporal resolution. Coastal water levels, waves, sea level rise and stream flows then drive a computationally rapid 2D flood solver that calculates overland flooding to the year 2100. Significant wave heights, wave runup, and the extent, depth, and duration of flooding are estimated for hundreds of extreme events to define storm recurrence intervals and map exposure in the future based on several climate change scenarios. Initial results across Whatcom County and Whidbey Basin reveal the spatial and temporal variability of shoreline and habitat exposure to daily, King tide and 1-, 5-, 10-, 20-, 50-, and 100-yr flood recurrence events with 7 projected sea level rise scenarios. Examples of CoSMoS results, a socioeconomic tool to assess details of projected population, property, and land cover exposure, and their integration into shoreline and restoration planning are discussed.

Session Title

Climate Science 2: Water

Conference Track

SSE8: Climate Change

Conference Name

Salish Sea Ecosystem Conference (2022 : Online)

Document Type

Event

SSEC Identifier

SSE-traditionals-180

Start Date

27-4-2022 9:45 AM

End Date

27-4-2022 11:15 AM

Type of Presentation

Oral

Genre/Form

conference proceedings; presentations (communicative events)

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Subjects – Topical (LCSH)

Flood control--Salish Sea (B.C. and Wash.); Coastal zone management--Salish Sea (B.C. and Wash.); Climatic changes--Salish Sea (B.C. and Wash.); Sea level--Salish Sea (B.C. and Wash.)

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

Type

Text

Language

English

Format

application/pdf

Share

COinS
 
Apr 27th, 9:45 AM Apr 27th, 11:15 AM

Downscaling future climate models for local flood and socioeconomic exposure across the Salish Sea with the Coastal Storm Modeling System (CoSMoS)

The U.S. Geological Survey Coastal Storm Modeling System (CoSMoS) is being developed for the Salish Sea to evaluate flood hazards at a scale of 1 m to support coastal planning into the next century. CoSMoS computes extreme water levels and flooding accounting for projected sea level rise and climate change effects on river floods and storms. Modeled tides and storm surge show a mean absolute error of 10 cm across NOAA and USGS tide gages over the hindcast period 2018-2019. Model forcings deconstructed over a 1985-2015 hindcast indicate that storm surge inside Puget Sound is driven primarily by atmospheric pressure anomalies (up to 45 cm), outer shelf wind and current dynamics (up to 45 cm), large-scale North Pacific Ocean dynamics and interannual phenomena like the El Niño-Southern Oscillation (up to 20 cm), and wind setup generated within the Salish Sea (up to 20 cm). Future conditions are evaluated with spatiotemporally varying fields derived from dynamically-downscaled global climate models at 12 km spatial and hourly temporal resolution. Coastal water levels, waves, sea level rise and stream flows then drive a computationally rapid 2D flood solver that calculates overland flooding to the year 2100. Significant wave heights, wave runup, and the extent, depth, and duration of flooding are estimated for hundreds of extreme events to define storm recurrence intervals and map exposure in the future based on several climate change scenarios. Initial results across Whatcom County and Whidbey Basin reveal the spatial and temporal variability of shoreline and habitat exposure to daily, King tide and 1-, 5-, 10-, 20-, 50-, and 100-yr flood recurrence events with 7 projected sea level rise scenarios. Examples of CoSMoS results, a socioeconomic tool to assess details of projected population, property, and land cover exposure, and their integration into shoreline and restoration planning are discussed.