Print Email Facebook Twitter Linking the river to the estuary: Influence of river discharge on tidal damping Title Linking the river to the estuary: Influence of river discharge on tidal damping Author Cai, H. Savenije, H.H.G. Toffolon, M. Faculty Civil Engineering and Geosciences Department Water Management Date 2013-07-15 Abstract The effect of river discharge on tidal damping in estuaries is explored within one consistent theoretical framework where analytical solutions are obtained by solving four implicit equations, i.e., the phase lag, the scaling, the damping and the celerity equation. In this approach the damping equation is obtained by subtracting the envelope curves of high water and low water occurrence, taking into account that the flow velocity consists of a tidal and river discharge component. Different approximations of the friction term are considered in deriving the damping equation, resulting in as many analytical solutions. In this framework it is possible to show that river discharge affects tidal damping primarily through the friction term. The application to the Modaomen and Yangtze estuaries demonstrates that the influence of river discharge on tidal damping can be significant in the upstream part of an estuary where the ratio of river flow to tidal flow amplitude is substantial. The analytical model is able to describe the main tidal dynamics with realistic roughness values in the upper part of the estuary, while a model with negligible river discharge can be made to fit observations only with unrealistically high roughness values. Moreover, the damping equation can be used to estimate river discharge on the basis of observed tidal damping, which makes the proposed analytical model a tool to obtain indirect information about quantities that are difficult to measure in the tidal region. To reference this document use: http://resolver.tudelft.nl/uuid:edf6631a-23bc-4f26-bfab-94938fc8d959 DOI https://doi.org/10.5194/hessd-10-9191-2013 Publisher European Geosciences Union ISSN 1812-2108 Source Hydrology and Earth System Sciences Discussions, 10, 2013 Part of collection Institutional Repository Document type journal article Rights © 2013 Author(s) 2013CC Attribution 3.0 License Files PDF Cai_2013.pdf 1.03 MB Close viewer /islandora/object/uuid:edf6631a-23bc-4f26-bfab-94938fc8d959/datastream/OBJ/view