Verification Study of a Bathystrophic Storm Surge Model.

摘要

A bathystrophic storm surge numerical model was verified, using data of historical hurricanes at selected traverses on the Gulf of Mexico and the east coast, by calibrating 'coupled' values of wind and bottom stress coefficients in hydrodynamic equations for the numerical computation. These coefficients represented model calibration constants that included more than the physical effects of wind and seabed friction. Surge hydrographs were calculated and compared with observed or recorded surge hydrographs of: (a) Hurricane of 1949 at Galveston and Freeport, Texas; (b) Hurricane Carla at Galveston and Freeport, Texas; (c) Hurricane Audrey at Eugene Island, Louisiana; (d) Hurricane Camille at Biloxi, Mississippi; and (e) Hurricane Carol at Narragansett Pier, Rhode Island. Comparisons were made with theoretical results for several hypothetical storm surge problems for which analytical solutions could be obtained. Although reasonable empirical solutions were obtained by combining values of initial rise and of coefficients of bottom friction and wind stress, the significance, variation and interdependence of these parameters could not be determined adequately because of limited historical data. Extrapolation of empirically derived wind stress and bottom friction relationships, as determined from lower windspeeds, to extreme probable maximum conditions associated with the synthetic hurricanes, could not be conclusively verified. Because of the complexity of the problem, data limitations, and the variability of different factors entering the calibration process, correlation for all historical hurricanes at all traverses was difficult to obtain.