Author(s): Yongjun Lu; Jialing Hao; Jianyu Lu; Haolin Li
Linked Author(s): Yongjun Lu
Keywords: Levee realignment; Flood control; Multiple channels; Boundary-fitted coordinate; Mathematical model
Abstract: As an example, the impact of the levee realignment project on the flood control of the city of Wenzhou has been studied by means of a 2D tidal flow mathematical model. The model verification results show that the tidal levels computed by the model are in good agreement with the field data, and the tidal velocity and rate of discharge are also in accordance with the data recorded. The variance in computation versus actual results is less than 10%. Therefore, the model can be used to accurately predict the changes of tidal level, flow velocity and discharge to forecast the effects of the project. It has been demonstrated from the computational results of the project scheme that in the condition of a flood frequency of 0.01, the tidal level will rise 0.03~0.04m and 0.04~0.08m respectively in the presence of project scheme 1 and project scheme 2. The depth-averaged velocity will increase 6~22% in the presence of project scheme 2 in the reach from the Tashan section to the Yuqishan section, and the change of tidal velocity is marginal outside of the project area. Because the blocked channel width and cross section area from project scheme 1 are less than that of project scheme 2, the change in tidal velocity in the presence of project scheme 1 is less than that of project scheme 2. The impact of the project on the bifurcation ratio of Jiangxinsi branched reach is negligible. The results computed by the model can be used as a reference for future decision-making.
Year: 2002