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Pacific Coastal and Marine Science Center

Coastal Processes

CoSMoS 3.0: Southern California

Location map of Southern California work.

Southern California study area. [Larger version]

CoSMoS 3.0 provides detailed predictions (meter-scale) of coastal flooding due to both future sea level rise and storms integrated with long-term coastal evolution (i.e., beach changes and cliff/bluff retreat) for the southern California region, from Point Conception (in Santa Barbara County) to Imperial Beach, CA.

Modeling from this project has been released through a phased approach. Phase 1 provided preliminary data from a 100-year storm event and five sea level rise scenarios (0, 0.5 meter, 1.0 meter, 1.5 meters and 2.0 meters), along with preliminary shoreline evolution modeling of sandy beaches and projected cliff retreat. These projections were made available to all five southern California counties in late 2015.

Phase 2 provides the full suite of 40 sea level rise (0–2 and 5 meters) and coastal storm (daily conditions, 1-year return, 20-year return, and 100-year return interval) scenarios, along with final coastal change projections for both sandy beaches and cliffs. Final results are now available for download for Los AngelesSan Diego, and Santa Barbara counties through USGS ScienceBase-Catalog. Final results for Ventura and Orange counties will be available in late spring 2017.

Flood projection map example for San Diego from Our Coast, Our Future.

Example of flood projections for San Diego as viewed on Our Coast, Our Future viewer. [Larger version]

Model enhancements for southern California include:

  • Improved system methodology from CoSMoS 1.0 for more accurate flood projections in high-interest embayments and estuaries
  • Long-term coastal evolution projections for sandy beaches and cliffs produced from a collection of state-of-the-art models and historical data
  • Downscaled winds from Global Climate Model (GCM) data for locally-generated seas and surge
  • Discharge from rivers for event response and long-term sediment supply
  • An improved baseline elevation DEM that incorporates recent LIDAR survey

In addition to the GIS shapefiles available on the USGS ScienceBase-Catalog, all model results are also available on the Our Coast, Our Future (OCOF) flood mapper, which provides a user-friendly web tool to review model projections. Complementary socioeconomic information is also available through the Hazards Exposure Reporting and Analytics (HERA), developed by Dr. Nathan Wood and Dr. Jeanne Jones from the USGS Western Geographic Science Center.

Southern California Regional Collaborations

CoSMoS Project Director Dr. Patrick Barnard explains flooding projections to City of LA planners. (Photo: Holly Rindge, USC Sea Grant) [Larger version]

CoSMoS 3.0 modeling results have been used in numerous projects throughout southern California. Through extensive stakeholder engagement, the CoSMoS team has partnered with many of the place-based organizations to help translate CoSMoS information and make it accessible to a broad range of audiences.  Key partners include:

Click for PDFFor more information, download CoSMoS v3.0 Southern California Bight:
Summary of Methods
(2.7 MB PDF).

Email us!For questions about the modeling, contact:
Dr. Patrick Barnard [] (Research Director) or
Dr. Li Erikson [] (Modeling Director).


Inundated areas shown should not be used for navigation, regulatory, permitting, or other legal purposes. The U.S. Geological Survey provides these data “as is” for a quick reference, emergency planning tool but assumes no legal liability or responsibility resulting from the use of this information.

The suggestions and illustrations included in these images are intended to improve coastal-flood awareness and preparedness; however, they do not guarantee the safety of an individual or structure. The contributors and sponsors of this product do not assume liability for any injury, death, property damage, or other effects of coastal flooding.

Use of trade names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey.


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Site designed, created, and maintained by: Laura Zink Torresan
Questions to: Patrick Barnard
Page Last Modified: 27 March 2017 (lzt)