Variational-based data assimilation to simulate sediment concentration in the Lower Yellow River, China

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Fang, Hong Wei ; Lai, Rui Xun ; Lin, Binliang ; Xu, Xing Ya ; Zhang, Fang Xiu ; Zhang, Yue Feng (2016)

The heavy sediment load of the Yellow River makes it difficult to simulate sediment concentration using classic numerical models. In this paper, on the basis of the classic one-dimensional numerical model of open channel flow, a variational-based data assimilation method is introduced to improve the simulation accuracy of sediment concentration and to estimate parameters in sediment carrying capacity. In this method, a cost function is introduced first to determine the difference between the sediment concentration distributions and available field observations. A one-dimensional suspended sediment transport equation, assumed as a constraint, is integrated into the cost function. An adjoint equation of the data assimilation system is used to solve the minimum problem of the cost function. Field data observed from the Yellow River in 2013 are used to test the proposed method. When running the numerical model with the data assimilation method, errors between the calculations and the observations are analyzed. Results show that (1) the data assimilation system can improve the prediction accuracy of suspended sediment concentration; (2) the variational inverse data assimilation is an effective way to estimate the model parameters, which are poorly known in previous research; and (3) although the available observations are limited to two cross sections located in the central portion of the study reach, the variational-based data assimilation system has a positive effect on the simulated results in the portion of the model domain in which no observations are available.
  • References (50)
    50 references, page 1 of 5

    Abbott, M. B., and Ionescu, F. (1967). “On the numerical computation of nearly horizontal flows.” J. Hydraul. Res., 5(2), 97-117.

    Ackers, P., and White, W. R. (1973). “Sediment transport: New approach and analysis.” J. Hydraul. Div., 99(11), 2041-2060.

    04016010-10 Bélanger, E., and Vincent, A. (2005). “Data assimilation (4D-VAR) to forecast flood in shallow-waters with sediment erosion.” J. Hydrol., 300(1-4), 114-125.

    Cao, Z., Pender, G., Wallis, S., and Carling, P. (2004). “Computational dam-break hydraulics over erodible sediment bed.” J. Hydraul. Eng., 10.1061/(ASCE)0733-9429(2004)130:7(689), 689-703.

    Celik, I., and Rodi, W. (1988). “Modeling suspended sediment transport in nonequilibrium situations.” J. Hydraul. Eng., 10.1061/(ASCE)0733 -9429(1988)114:10(1157), 1157-1191.

    Chanson, H. (2004). Environmental hydraulics of open channel flows, Elsevier Butterworth Heinemann, Amsterdam, Netherlands.

    Chen, W., and Chau, K. W. (2006). “Intelligent manipulation and calibration of parameters for hydrological models.” Int. J. Environ. Pollut., 28(3-4), 432-447.

    Cheng, C., Chau, K., Sun, Y., and Lin, J. (2005). “Long-term prediction of discharges in manwan reservoir using artificial neural network models.” Advances in Neural Networks-ISNN 2005, J. Wang, X.-F. Liao, and Z. Yi, eds., Springer, Berlin, 1040-1045.

    Ch'ien, N., and Wan, C. (1999). Mechanics of sediment transport, ASCE, Reston, VA.

    Cunge, J. A. (1980). Practical aspects of computational river hydraulics, Pitman Advanced Publications Program, Boston.

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