i-manager Publications

Anomalous dispersion in backwater river flows analyzed by a numerical stochastic approach

Marilena Pannone*

Aggregate Professor, School of Engineering, University of Basilicata, Italy.

Periodicity:August - October'2012
DOI : https://doi.org/10.26634/jfet.8.1.1976

Abstract

The article focuses on the analytical/numerical modelling of the solute transport taking place within large rivers flowing through wide alluvial plains, and characterized by a weak bed slope, near the confluence into large reservoirs collecting water for potable or agricultural destinations. The aim of the study is represented by the analysis of the effect that the macroscopic morphological features of the channel induce on the hydrodynamic dispersion of effluents accidentally injected along its course, when a downstream obstacle can critically slow down the flow, preventing the dilution of the solutes. A recent work (Yudianto & Yuebo, 2008) has dealt with the problem resorting to a Eulerian numerical approach, and coming to the conclusion that, in the most part of the gradually varying steady flows, the adoption of a single velocity value (i.e. the corresponding uniform-flow section average) is sufficient to represent them even in terms of pollutants dispersion. Present work analyzes the dispersive properties of non uniform fluvial streams by an analytical-numerical stochastic Lagrangian approach and identifies the existence of a characteristic travel time, which is function of bed slope and width to depth ratio, beyond which the longitudinal hydrodynamic dispersion undergoes a clear and potentially dangerous regress.

Keywords

Backwater Flows, Solutes Dispersion, Lagrangian Stochastic Approach, Particle-Tracking Techniques.

How to Cite this Article?

Pannone, M. (2012). Anomalous Dispersion In Backwater River Flows Analyzed By A Numerical Stochastic Approach. i-manager’s Journal on Future Engineering and Technology, 8(1), 25-31. https://doi.org/10.26634/jfet.8.1.1976

References

[1]. Batchelor, G.K. (1952). Diffusion in a field of homogeneous turbulence, 2: The relative motion of particles. Proc. Cambridge Philos. Soc., 48, 345-362.

[2]. Chatanantavet, P., Lamb, M.P. & J.A. Nittrouer (2012). Backwater controls of avulsion location on deltas. Geophysical Research Letters, 39, L01402.

[3]. Deng, Z., Singh, V.P., & L. Bengtsson (2001). Longitudinal dispersion coefficient in straight rivers. Journal of Hydraulic Engineering, 127, 919-927.

[4]. Elder, J.W. (1959). The dispersion of a marked fluid in turbulent shear flow. Journal of Fluid Mechanics, 5, 544- 560.

[5]. Fischer, H.B., List, E.J., Koh, R.C.Y., Imberger, J., & N.H. Brooks (1979). Mixing in inland and coastal waters. Academic Press, New York, pp. 483.

[6]. Hidayat, H., Vermeulen, B., Sassi, M.G., Torfs, P.J.J.F., & A.J.F. Hoitink (2011). Discharge estimation in a backwater affected meandering river. Hydrol. Earth Syst. Sci., 15, 2717-2728.

[7]. Lamb, M.P., Nittrouer, J.A., Mohrig, D., & J. Shaw (2012). Backwater and river plume controls on scour upstream of river mouths: Implications for fluvio-deltaic morphodynamics, J. Geophys. Res., 117, F01002.

[8]. Pannone, M., & P.K. Kitanidis (1999). Large-time behaviour of concentration variance and dilution in heterogeneous formation. Water Resour. Res., 35, 623- 634.

[9]. Pannone, M. (2010). Effect of nonlocal transverse mixing on river flows dispersion: A numerical study. Water Resour. Res., 46, W08534.

[10]. Pannone, M. (2012). Longitudinal dispersion in river flows characterized by random large-scale bed irregularities: first-order analytical solution. Journal of Hydraulic Engineering, 138, 400-411.

[11]. Seo, I.W., & T.S. Cheong (1998). Predicting longitudinal dispersion coefficient in natural streams. Journal of Hydraulic Engineering, 124, 25-32.

[12]. Taylor, G.I. (1954). The dispersion of matter in turbulent flow through of a pipe. Proc. Royal Soc., London, Ser. A, 223, 446-468.

[13]. Yanites, B.J., Webb, R.H., Griffiths, P.G., & C.S. Magirl (2006). Debris flow deposition and reworking by the Colorado River in Grand Canyon, Arizona. Water Resour. Res., 42, W11411.

[14]. Yudianto, D., & X. Yuebo (2008). Contaminant distribution under non uniform velocity of steady flow regimes. Journal of Applied Sciences in Environmental Sanitation, 3, 79-90.

Anomalous dispersion in backwater river flows analyzed by a numerical stochastic approach

Abstract

Keywords

How to Cite this Article?

References

If you have access to this article please login to view the article or kindly login to purchase the article

Purchase Instant Access

Options for accessing this content:

	North Americas,UK, Middle East,Europe		India	Rest of world
	USD	EUR	INR	USD-ROW
Pdf	35	35	200	20
Online	35	35	200	15
Pdf & Online	35	35	400	25