| As the main coastal protection structures, sea dikes are mainly used to resist theintrusion of waves, aiming at avoiding attacks due to spring tide, high tide and stormsurge in the area of coastal or estuarine area, and are of great significance to the safetyof social economy and residents’ property. As all kinds of extreme sea conditionscaused by typhoon are subject to flood overtopping, the focus study of this paper isthat how to explore rational and effective methods for risk analysis of floodovertopping caused by the joint action of multiple risk factors.In this paper, with an eye on to the self-similarity and scaling problem inhydrology, the characteristic of flood overtopping risk factors-tide level, storm surgeand passing upriver flood-on time scale are investigated by using the fractal theory.And two new combination risk analysis models respectively based onFLR andFLC Rconstrains which follows fractal distribution are developed and applied on therisk analysis of the sea dike overtopping in Woosung,Shanghai under tide level, stormsurge and passing upriver flood. Lastly, mutual information has been adopted to verifyand estimate the effectiveness and reliability of the two newly developed methods. Bymeans of case testing, it has been found that the combination risk analysis modelbased on constrainFLC Ris more reliable than the one based on constrainFLR. |
