Coastal Flooding & Solutions, Workshop Case Studies

Coastal Storm Modeling System (CoSMoS)

Location: California, but national expansion of derivative approaches underway

Submitted By: Patrick Barnard - US Geological Survey

Project URLs: www.usgs/cosmos,,

Project Description

Coastal inundation due to sea level rise (SLR) is projected to displace hundreds of millions of people worldwide over the next century, creating significant economic, humanitarian, and national-security challenges. However, the majority of previous efforts to characterize potential coastal impacts of climate change have focused primarily on long-term SLR with a static tide level, and have not comprehensively accounted for dynamic physical drivers such as tidal non-linearity, storms, short-term climate variability, erosion response and consequent flooding responses. Here we present a dynamic modeling approach, the Coastal Storm Modeling System (CoSMoS) that estimates climate-driven changes in flood-hazard exposure by integrating the effects of SLR, tides, waves, storms, and coastal change (i.e. beach erosion and cliff retreat). We show that for California, USA, the world’s 5th largest economy, over $230 billion of property equating to more than 6% of the state’s GDP and 600,000 people could be impacted by dynamic flooding by 2100; a threefold increase in exposed population than if only SLR and a static coastline are considered.

Key Successes

extensive use in climate adaptation planning, policy and site evaluations


accounting for all the relevant physical processes, computational expense, developing universally usable scenarios and products

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