Print Email Facebook Twitter Hurricane Surge Risk Reduction For Galveston Bay Title Hurricane Surge Risk Reduction For Galveston Bay Author Stoeten, K.J. Contributor Jonkman, S.N. (mentor) Brody, S. (mentor) Labeur, R.J. (mentor) Ledden, M. (mentor) Willems, A. (mentor) Faculty Civil Engineering and Geosciences Department Hydraulic Engineering Date 2013-10-29 Abstract More than five years after Hurricane Ike devastated the Galveston Bay Area, the most critical challenge remains; reducing flood vulnerability. In response to Hurricane Ike’s disastrous impact, several structural flood risk reduction strategies have been proposed. Some advocating local solutions, others advocating system-wide coastal barriers. The relationship between storm surge within Galveston Bay and storm surge at the open coast may profoundly affect the performance of these local or system-wide solutions. Limited understanding of bay behavior under hurricane forcing limits the ability to select the optimal solution. To assess the bay behavior under hurricane forcing, a probabilistic behavior-oriented storm surge model has been developed. The model couples meteorological forcing with hydrodynamic response and provides a first-estimate of storm surge within simplified semi-enclosed bays. A large suite of synthetic parametric hurricane wind fields provides input for the storm surge model. Storm surge at the open coast is obtained by solving the one-dimensional depth integrated shallow water equations. Storm surge within the semi-enclosed bay relies on a parametric relation between wind set-up and storm surge at the open-coast. Hindcasts of historic storms show that the model provides a reasonable estimate of storm surge within the bay, with a typical error of ±0.5 meter. Storm surge within Galveston Bay is a delicate balance between inflow and local wind set-up. Simulations show that local wind set-up contributes up to 50% to the surge within the bay, depending on landfall location and storm intensity. Results indicate that the 1/1,000 yr-1 surge at the northern bay end exceeds the 1/1,000 yr-1 surge at the open coast by about 0.5 meter. The 1/10,000 yr-1 surge at the northern bay end exceeds the 1/10,000 yr-1 surge at the open coast by about 1.0 meter. Although significant, obtained results do not indicate that the difference in surge elevation plays a crucial role in strategy selection. To assess the benefits of a coastal spine, ship channel gate or Texas City levee upgrade, a preliminary flood risk assessment has been performed. For each strategy, the benefits in terms of risk reduction are estimated by relating simulated surge probabilities to residential exposure, industrial exposure and surface elevation. Comparing the estimated investment cost and benefits of each strategy allows an informed monetary comparison of the individual risk reduction strategies. The flood risk assessment confirms that the Galveston Bay Area is highly vulnerable to storm surge. Existing regulations solely require industrial complexes to protect up to the 100-year flood level. Consequently, residential exposure significantly exceeds industrial exposure for return periods of up to once per 100 years. Industrial exposure outweighs residential exposure for less frequent events. Considerable benefits can be achieved by protecting both residential property and industrial assets. Preliminary results indicate that a coastal spine significantly reduces storm surge within the bay and yields the highest benefits in terms of risk reduction. The ship channel gate and the Texas City Levee Upgrade yield a similar rate of return but achieve considerably less benefits. Subject Galveston BayhurricaneHoustonflood riskstorm surgeIkeHurricane Ikeflood vulnerabilityGalvestonsemi-enclosed bayprobabilisticlandfallflood risk reduction strategiesIke dike To reference this document use: http://resolver.tudelft.nl/uuid:3239a90e-42ef-485b-a73a-d39a99c1611a Part of collection Student theses Document type master thesis Rights (c) 2013 Stoeten, K.J. Files PDF Stoeten_KJ_-_Hurricane_Su ... on_Bay.pdf 19.46 MB Close viewer /islandora/object/uuid:3239a90e-42ef-485b-a73a-d39a99c1611a/datastream/OBJ/view