Impact of River-Tide Dynamics on the Temporal-Spatial Distribution of Residual Water Level in the Pearl River Channel Networks
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The behavior of the residual water level in estuarine environment is complex due to the highly nonlinear interaction between river flow and tide and the contributions made by these two external forcing to the dynamics of the residual water level are not yet fully understood. In this study, we investigate the effect of river-tide dynamics on the temporal-spatial changes of flow in terms of residual water level in the Pearl River channel networks, which is one of the complex channel networks in the world. Making use of a nonstationary tidal harmonic analysis, the continuous time series observations of water level covering a spring-neap cycle in 1999 (representing flood season) and 2001 (representing dry season) collected from around 60 stations in the Pearl River channel networks have been used to extract the temporal-spatial changes in stage and tidal properties (including amplitudes and phases) as a function of variable freshwater discharge and ocean tide. It was shown that the averaged residual water level during the flood season (ranging 0–5 m) is one order magnitude than that during the dry season (ranging 0–0.35 m). The distribution of the residual water level clearly indicates that the Pearl River channel networks feature two sub-systems, i.e., the central part of the channel networks being river-dominated with high value of residual water level and the eastern and western sides being tide-dominated with low value of residual water level. To understand the relative importance of river flow and tide on the temporal-spatial distribution of the residual water level, an idealized model is subsequently applied to the Modaomen estuary, which debouches the largest portion of river discharge into the South China Sea. Analytical results showed that the residual water level is mainly determined by the variation of the freshwater discharge for the flood season, while it is primarily controlled by the tidal forcing for the dry season and features a typical spring-neap cycle.
KeywordsResidual water level River-tide dynamics NS_TIDE Idealized model Channel networks
The research reported herein is funded by the National Key R&D program of China (Grant No. 2016YFC0402600), by the National Natural Science Foundation of China (Grant Nos. 51709287, 41106015, and 41476073), and by the Water Resource Science and Technology Innovation Program of Guangdong Province (Grant No. 2016-20).
- Cai, H., H.H.G. Savenije, Q. Yang, S. Ou, and Y. Lei. 2012. Influence of river discharge and dredging on tidal wave propagation: Modaomen estuary case. Journal of Hydraulic Engineering ASCE 138 (10): 885–896. https://doi.org/10.1061/(ASCE)HY.1943-7900.0000594.CrossRefGoogle Scholar
- Dronkers, J.J. 1964. Tidal computations in rivers and coastal waters, 518. Amsterdam: North-Holland Publishing Company.Google Scholar
- Godin, G. 1985. Modification of river tides by the discharge. Journal of Waterway, Port, Coastal, and Ocean Engineering ASCE 111 (2): 257–274. https://doi.org/10.1061/(ASCE)0733-950X(1985)111:2(257).CrossRefGoogle Scholar
- Godin, G. 1999. The propagation of tides up rivers with special considerations on the upper Saint Lawrence river. Estuarine, Coastal and Shelf Science 48 (3): 307–324. https://doi.org/10.1006/ecss.1998.042210.1006/ecss.1998.0422.CrossRefGoogle Scholar
- Guo, L.C., M. van der Wegen, D.A. Jay, P. Matte, Z.B. Wang, D. Roelvink, and Q. He. 2015. River-tide dynamics: Exploration of nonstationary and nonlinear tidal behavior in the Yangtze River estuary. Journal of Geophysical Research 120 (5): 3499–3521. https://doi.org/10.1002/2014JC010491.Google Scholar
- Hoitink, A.J.F., Hoekstra, P., and van Maren, D.S. 2003. Flow asymmetry associated with astronomical tides: Implications for the residual transport of sediment. Journal of Geophysical Research 108: C10,3315. https://doi.org/10.1029/2002JC001539.
- Jay, D.A., Leffler, K., Degens, S. 2011. Long-term evolution of Columbia River Tides. Journal of Waterway Port Coastal and Ocean Engineering ASCE 137(4): 182–191. https://doi.org/10.1061/(ASCE)WW.1943-5460.0000082.
- Jay, D.A., K. Leffler, H.L. Diefenderfer, and A.B. Borde. 2015. Tidal-fluvial and estuarine processes in the Lower Columbia River: I. Along-channel water level variations, Pacific Ocean to Bonneville Dam. Estuaries and Coasts 38 (2): 415–433. https://doi.org/10.1007/s12237-014-9819-0.CrossRefGoogle Scholar
- Luo, X.L., Zeng, E.Y., Ji, R.Y., Wang, C.P. 2007. Effects of in-channel sand excavation on the hydrology of the Pearl River Delta, China. Journal of Hydrology 343(3–4): 230–239. https://doi.org/10.1016/j.jhydrol.2007.06.019.
- Matte, P., Y. Secretan, and J. Morin. 2014. Temporal and spatial variability of tidal-fluvial dynamics in the St. Lawrence fluvial estuary: An application of nonstationary tidal harmonic analysis. Journal of Geophysical Research 119 (9): 5724–5744. https://doi.org/10.1002/2014JC009791.Google Scholar
- Parker, B.B. 1991. The relative importance of the various nonlinear mechanisms in a wide range of tidal interactions. In Tidal hydrodynamics, ed. B.B. Parker, 236–268. New York: Wiley.Google Scholar
- Savenije, H.H.G. 2005. Salinity and tides in alluvial estuaries. New York: Elsevier.Google Scholar
- Savenije HHG, 2012. Salinity and tides in alluvial estuaries (2nd completely revised edition). Available at www.salinityandtides.com.
- Savenije, H.H.G., Toffolon, M., Haas, J., Veling, E.J.M. 2008. Analytical description of tidal dynamics in convergent estuaries. Journal of Geophysical Research 113: C10025. https://doi.org/10.1029/2007JC004408.
- Vignoli, G., Toffolon, M., Tubino, M. 2003. Non-linear frictional residual effects on tide propagation. In: Proceedings of XXX IAHR Congress, vol. A, 24–29 August 2003, Thessaloniki, Greece, 291–298, 2003.Google Scholar