Developing Unsteady Flow Numerical Model Semi-Coupled with Sediment Transport in River Systems

Authors

1 Phd graduate of razi university

2 associate professor

3 professor

Abstract

It is so essential for engineers to be able to predict the places in which deposition and scouring occurs. Numerical models are valuable tools for estimating flow conditions and sediment transport, and are widely applied in water resources management. The main goal of this study is to develop one dimensional, unsteady, hydrodynamic model which can be used for simulating flow and sediment transport as semi-coupled model in river systems. In this research, the Saint- Venant’s equations are numerically solved for river systems. In this research a semi implicit finite difference scheme is developed to solve the Saint- Venant equations for unsteady flow. The linear equations are produced based on the partial differential equations and the staggered technique. After solving the above equations, the computed hydraulic parameters in this part are sent to the sediment transport segment. . The dynamic advection- dispersion equation and the sediment continuity partial differential equation were applied to calculate the suspended sediment concentration and bed load transport, respectively. The Exner equation is then used to predict the changes in the river bed elevations. Finally, the model was compared to the Hec-Ras Model and the results showed that the developed model has good accuracy.
Keywords: Sediment Transport, Flow Routing, River Systems, Numerical Model

Keywords


Abbott MB and Basco DR, 1997. Computational Fluid Dynamics: An introduction for engineers. Longman Singapore Publisher, Singapore.
Bai Y and Duan JG, 2014. Simulating unsteady flow and sediment transport in vegetated channel network. Journal of Hydrology 515:90-102.
Cunge JA, Jr FM and Verwey A, 1980. Practical Aspects of Computational River Hydraulics. Pitman Publishing Limited, London.
Devris M, 1973. River bed variations – aggradation and degradation. Pp. 1-10. Proc. Int. Seminars of Hydraulic of Alluvial Streams, IAHR, Netherlands.
Ghobadian R and Fathi-Moghadam M, 2014. Estimation of seepage losses in ephemeral network and branching streams. Journal of Hydrologic Engineering ASCE 19(2): 299–307.
Ghobadian R and Ghanbari S, 2018. Impact of bed materials grain size distribution on sediment transport path and erosion- sedimentation pattern at the river confluence. Water and Soil Science, University of Tabriz 28(4): 29-42.
Guan M and Liang Q, 2017. A two-dimensional hydro-morphological model for river hydraulics and morphology with vegetation. Environmental Modelling & Software 88:10-21.
Hongming H, Yong QT, Xingmin Mu, Jie Zh, Zhanbin Li , Nannan C, Qingle Zh, Soksamnang K, Chantha O, 2015. Confluent flow impacts of flood extremes in the middle yellow river. Quaternary International 380:382-390.
Juxiang J, Jing H, Liu C and Tao, J, 2011. Hydrodynamic and water quality models of river network and its application in the Beiyun River. DOI: 10.1109/icbbe.2011.5780735.
Kashefipour SM and Falconer RA, 2002. Significance of Empirical Coefficients on the Accuracy of the Numerical Solution of the ADE. Pp. 95-102. Proceedings of the fifth International hydroinformatics Conference, July 1-5, Cardiff, UK.
Lin B, 1984. Current study of unsteady transport of sediment in China. Pp. 337-342. Proc, Japan–China Bilateral Seminar on River Hydraulics and Engineering Experiences, Tokyo–Kyoto–Saporo, Japan.
Lyn DA, 1987. Unsteady sediment transport modelling. Journal of Hydraulic Engineering, Proc, ASCE 113(9): 1-15.
Maleki Safarzadeh F and Khan A, 2016. 1-D coupled non-equilibrium sediment transport modeling for unsteady flows in the discontinuous Galerkin framework. Journal of Hydrodynamics 28(4):534-543.‏
Meyer-Peter E and Muller R, 1948. Formulas for bed-load transport. IAHR, 2nd Meeting, Stockholm, 25th May, Sweden.
Mohamadi S, Ghobadian R and Kashefipour SM, 2016. Coupling Green-Ampt and Saint-Venant Equations for Estimating of Transmission Losses during Flood Routing in Rivers. Journal of Irrigation engineering and sciences 39(1):143-153.
Spasojevic M and Holly FM, 1990. Numerical Simulation of Twodimensional Deposition and Erosion Patterns in Alluvial Water Bodies. IIHR Rep. No. i49, The Univ. of Iowa, Iowa City, Iowa.
Struiksma N, Olesen KW, Flokstra Cde and Vriend, HJ, 1985. Bed deformation in curved alluvial channels. Journal of Hydraulic Research 23(1):57-79.
Termini D, 2014. Non-uniform sediment transport estimation in non-equilibrium situation: case studies, Procedia Engineering 70:1639–1648.
Wu W, 2004. Depth-averaged two-dimensional numerical modeling of unsteady flow and nonuniform sediment transport in open channels. Journal of Hydraulic Engineering ASCE, 130(10):1013–1024.
Wu W and Wang SS, 2007. One-dimensional modeling of dam- break flow over movable beds. Journal of Hydraulic Engineering ASCE, 133(1):48-58.
Wu XL, Xiang XH, Wang CH, Li L, Wang Ch, 2014. Water level updating model for flow calculation of river networks. Water Science and Engineering 7(1):60-69.
Zhang S, Duan, J and Strelkoff T, 2013. Grain-scale nonequilibrium sediment transport model for unsteady flow. Journal of Hydraulic Engineering 139 (1):22–36.