U.S. coastal communities are increasingly vulnerable to sea level rise, tidal flooding, higher storm surge, coastal erosion, and other climate-related impacts.^[1] To help communities in southern California plan for rising water levels, a NASA DEVELOP team collaborated with the U.S. Geological Survey’s (USGS) Pacific Coastal and Marine Science Center, in partnership with the California Coastal Commission, to create detailed projections of flooding from sea level rise and coastal storms along the central and southern California coastline that can inform planning to reduce climate-related risks to future development.

 

The team updated USGS’s online coastal flood prediction tool, the Coastal Storm Modeling System (CoSMoS), using data collected via aircraft and satellite (including the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) mounted on NASA aircraft and the Landsat 8 satellite) to create more detailed flood projections for the central and southern California coastline. The team focused on very high tide events known as king tides that already cause regular flooding in some low-lying communities in southern California, offering a preview of events that communities can expect to occur more frequently as sea level continues to rise. The updated data allowed the project team to see details from particular king tide events and generate a new baseline for the impacts of future king tides along southern California’s coastline.

 

Using the new satellite and aircraft data, USGS plans to assess the accuracy of and update the flood simulations provided by CoSMoS, which, in turn, will provide better flood hazard forecasts for southern California communities. The updated data are among the resources the California Coastal Commission will use as a guide for identifying areas likely to be affected by flooding and erosion as sea level continues to rise.

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