Direct Joint Probability Method for Estimating Extreme Sea Levels

作者：Liu Joan C; Lence Barbara J^*; Isaacson Michael

来源：Journal of Waterway, Port, Coastal and Ocean Engineering, 2010, 136(1): 66-76.

DOI：10.1061/(ASCE)0733-950X(2010)136:1(66)

A key design element in coastal structures is the crest elevation which protects against damages due to overflowing and overtopping. In order to avoid overflowing, the design crest elevation should be above the extreme flood level, which is usually composed of tides and storm Surges but Could also include tsunami, El Nino, and other climatologic and geologic effects. The extreme flood level may be determined with the annual maxima, simple addition, or joint probability methods (JPM). These methods have various limitations in terms of the amount of required data. the representation of factors contributing to sea level fluctuations, the ability to assess the joint probability of these factors. and the degree of data independence required. To minimize overtopping, the design crest elevation should be above the extreme sea level which is evaluated considering wave runup and the extreme flood level. Wave runup estimates are based on selected extreme flood levels and the extreme wave climate, data for which are often dependent. A modification of the JPM, the direct JPM (DJPM), is developed for estimating extreme flood and sea levels. This method may be applied to consider any number of dependent contributing factors. Data for the City of Richmond, B.C., Canada, are used to demonstrate the DJPM. The DJPM provides an estimate of the extreme flood level for Richmond that is within the same range as those obtained using traditional estimation methods. The results indicate a large difference between extreme flood and sea level estimates. The sea levels at Richmond are also increasing due to climate and tectonic effects. A hybrid direct joint probability-simple addition method is applied to consider these effects.

• 出版日期2010-2