Abstract:Design water levels are important hydrological parameters in nearshore port and waterway engineering.They can be estimated from the characteristic tidal levels such as mean tidal range if there are insufficient basic data in the early stage of the project.Water levels of 95 representative tide stations along the coast of China from Tide Tables are collected,and the design high/low water level and the characteristic tidal levels are calculated to analyze the linear fitting correlation of them.The method of estimating design water levels by mean tidal range,mean high water spring or mean high high water of regression tide are explored.Errors of the formulas are compared with the existing ones in the codes,and recommended formulas are provided.The results show that compared to the standard formula,the recommended design high water level formula can reduce the absolute mean error by 5-29 cm and the standard deviation by 0-14 cm,while the design low water level formula can reduce the absolute mean error by 12-20 cm and standard deviation by 2-8 cm.The recommended formula have smaller value error and standard deviation，better accuracy and stability than the ones in the codes do,and can be used as a basis for estimating the design water levels in the early stage of the project.
