ENVIRONMENTAL CONTOUR OF WIND-WAVE-STORM SURGES INDUCED BY TYPHOONS

Typhoons usually induce strong winds, huge waves and storm surges when they make landfall. The acquisition of data of the typhoon-generated winds, waves, and storm surges and the determination of the corresponding environmental design parameters with a given return period are two critical issues that restrict the design of sea-crossing bridges. Taking Zhoushan sea area where many sea-crossing bridges are located as an example, a SWAN+ADCIRC coupling model was employed to simulate the metocean conditions under typhoons. Hindcast simulations of 49 typhoons that affected the example site in the past 32 years were conducted. The environmental contours with a 100-year return period were calculated using the simulated winds, waves and storm surges. The influence of the data selection on the environmental contours was investigated. The results show that: The numerical model employed in this study can provide reliable data for developing joint probability and environmental contour models; The nested three-dimensional Copula well fits the trivariate joint probability distribution of typhoon-induced winds, waves and storm surges. The environmental contours with a given return period depend on the data selection method, and the maximum storm surge is the most sensitive parameter to this factor.