| Summary: | Hurricane induced storm surges can be destructive and can pose great threats to coastal communities. There are many factors affecting storm surges, including the hurricanes intensity and movement, the bathymetry and coastline of affected area, rainfall, tide, and river stage. This thesis focuses on the effects of hurricane approach angle (θ) and forward speed (U), which together describe the hurricanes motion. The problem is approached through several numerical experiments with increasing complexity. First are some process studies of long wave propagations near the coast, followed by examination of the generation of long waves by a traveling wind field. The central part consists of a systematic experiment looking into the two hurricane parameters θ and U, with additional tests on bottom friction and hurricane size. In the end is an experiment with more realistic bathymetry and inundation treatment.
Storm surge is a surface wave caused by atmospheric forcing. In the open ocean it has small amplitude and propagates at the speed of a shallow water gravity wave once it is away from the area of generation. After reaching the coast, it increases to a more dangerous level and extends up and down-coast. It is found in this study that θ and U have significant effects on storm surge. The mechanism is related to Kelvin waves characteristics of propagation. Because of the boundary-confinement and the unidirectional propagation of the Kelvin wave, certain hurricane movements defined by a combination of θ and U may either be favorable or non-favorable for storm surge development. It was also found that hurricane size can have important effects on storm surge amplitude. When more realistic bathymetry is used, experiments suggest that the conclusions made with simplified experiments are still valid and should not be overlooked.
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