4.5　Seiche Set-up

4.5.1　Where the plant is located on the bank of an enclosed or partially enclosed water body，the possibility of seiche occurrence shall be evaluated.

4.5.2　Where long-term measured tidal level and other related data is available for the plant site，the maximum possible seiche can be determined using the probabilistic and deterministic method with their results cross validated.

4.5.3　The seiche set-up shall be calculated in the steps given below:select several typical seiche processes，analyze the environmental background of each individual seiche，determine the external driving force for each seiche and check the reliability of the numerical model.The main parameters for evaluating a seiche include amplitude，cycle，cause，frequency，and seasonal variation.

4.5.4　The numerical model shall be used to simulate historical possible seiche in the environmental background on an annual basis，and obtain the annual series of seiche extremes to extrapolate the seiche that has a multiple-year return period.The force parameters that may cause the most significant seiche at the site shall be chosen to calculate the maximum possible set-up.The results shall be compared and analyzed to determine the maximum possible seiche set-up in a reasonable manner.