Study On Calculation Of Composite Probability For Tidal Level And Wave In Estuary Region

At first, the hydrologic characteristics of estuary region and the current research situation about consistency correction for hydro-sequence and composite probability for tidal level and wave are elaborated. The methods to evaluate design value combines tidal level and wave when the data are inconsistent are studied in this paper, taking the design levee elevation of Lianxinggang and Luchaogang for example, which are located in the estuary of Yangtze River and the Hangzhou Bay.The tidal level data using in programming are interpolated and extended. Followed by stochastic characteristics analysis, the inconsistent tidal level data need consistency correction so that the data can be used as stochastic independent sample in the frequency calculation. At the same time, the wave data are calculated.By the statistical test, the applicability about three methods to correct inconsistency of hydro-sequence is studied thoroughly. Considered that the norm method to evaluate the design value combines tidal level and wave has some faults such as the design frequency is not definite and the design value is upward bias, the composite frequency method, composite parameter method and indirect norm method are put forward, and their errors are analyzed quantitatively. The research shows that the design value combines tidal level and wave by composite frequency method is considered to be the reference for design levee elevation.According to these theories, the design values of Luchaogang and Lianxinggang are estimated, as the basis for design levee elevation in the area.The achievements of this paper will directly provide guidance for design criterion for Shanghai's coast engineering, and the methods about consistency correction and design value combines tidal level and wave are applicable to other similar region.