A modeling system for predicting the impact of severe storms on the U.S. West Coast
Abstract
Storm hazards on the U.S. West Coast are generally thought of as being less severe than the more dramatic hurricane impacts that affect the Gulf of Mexico and East Coasts. However, the magnitude, duration and economic and societal impacts of West Coast storms can still be substantial. Storms during the 1982-83 El Niño winter resulted in 36 casualties and over $1.2 billion in damage to the State of California, and current research suggests that increasing storm intensity, frequency, and wave heights will increase coastal-hazards risks on the West Coast for the foreseeable future. To begin to address the increased risk, the U.S. Geological Survey is leading the development of a modeling system for forecasting the impact of winter storms along the U.S. West Coast. A prototype has been developed for Southern California and is being tested with a hypothetical extreme winter storm scenario designed by atmospheric scientists. The modeling system has been designed to be run operationally or with prescribed scenarios, and utilizes atmospheric forcing information with a suite of state-of-the-art physical process models to provide detailed prediction of ocean currents, deep-water and near-shore wave heights, coastal wave runup, and the resulting total water levels on beaches and cliffed coastlines. Research-grade predictions of coastal flooding, inundation, erosion, and cliff failure are also provided. The modeling system utilizes an integrated, nested structure whereby regional wave and water level models are driven by boundary conditions derived from a global wave model, regional seas and swell data from an extensive wave buoy network, a global tide model from satellite altimetry, and atmospheric pressure and wind forecasts. Wave parameters and water levels from the regional models drive local, high resolution cross-shore profile models and 2D-morphological models. Data from these models, in turn, provide boundary conditions for a Bayesian cliff failure model. This paper reports on the complex modeling system structure and preliminary testing. Large waves striking Pacific Grove, CA, USA, in December 2006 (photo by Patrick Barnard).
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMNH14A..03B
- Keywords:
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- 3020 MARINE GEOLOGY AND GEOPHYSICS / Littoral processes;
- 3022 MARINE GEOLOGY AND GEOPHYSICS / Marine sediments: processes and transport;
- 4217 OCEANOGRAPHY: GENERAL / Coastal processes;
- 4255 OCEANOGRAPHY: GENERAL / Numerical modeling