Assessing Erosion Hazards due to Floods on Fans: Physical Modeling and Application to Engineering Challenges
Publication: Journal of Hydraulic Engineering
Volume 143, Issue 8
Abstract
Experiments using a 1∶30 scale physical model show that channel degradation on alluvial fans is dominated by lateral channel migration rather than vertical incision. The results are used to estimate the exposure probability during single flood events with peak flows up to twice the formative flow, considering both the burial depth beneath the channel bed and the setback from the channel banks. For the largest flows modeled, the exposure probability fell below the detection limits for this analysis when the burial depth was greater than approximtely 3.6 times the mean flow depth, and the lateral setback distance was greater than approxinately 0.9 times the mean flow width for the formative flow. The minimum depth-of-cover criterion accounts for the worst-case occurrence of net bed degradation during a single flood event, but does not consider the vertical degradation that could occur in channels because of knickpoint development and migration, or in channels with engineered banks that prevent channel width adjustments; they also do not consider the potential effects of debris flows. These hazards are driven by different processes and require different analyses to evaluate the potential exposure risk. Because the experiments evaluated the effects of single flood events, the results do not account for shifting channel position over time, and they are intended to guide monitoring of channel behavior for existing infrastructure. The results also can be used to guide infrastructure design, but in this case the design will need to consider the cumulative effect of channel migration and avulsion over the design life span of the infrastructure.
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Acknowledgments
This research was supported by two NSERC Engage grants supporting collaboration between Dr. Brett Eaton and BGC Engineering. The manuscript has benefited greatly from the input of two anonymous reviewers.
References
Ashmore, P. (2013). “Morphology and dynamics of braided rivers.” Treatise on Geomorphology, 9, 289–312.
Benda, L., and Dunne, T. (1987). “Sediment routing by debris flow.” IAHS-AISH Publ., 165, 213–223.
Blench, T. (1969). Mobile-bed fluviology: A regime theory treatment of canals and rivers for engineers and hydrologists, Univ. of Alberta Press, Edmonton, AB, Canada.
Bray, D. (1975). “Representative discharges for gravel-bed rivers in Alberta, Canada.” J. Hydrol., 27(1), 143–153.
Buffington, J. M., Montgomery, D. R., and Greenberg, H. M. (2004). “Basin-scale availability of salmonid spawning gravel as influenced by channel type and hydraulic roughness in mountain catchments.” Can. J. Fish. Aquat. Sci., 61(11), 2085–2096.
Bull, W. B. (1964). “Alluvial fans and near surface subsidence in western Fresno County, California.” U.S. Government Printing Office, Washington, DC, 1–71.
Carling, P. (1988). “The concept of dominant discharge applied to two gravel-bed streams in relation to channel stability thresholds.” Earth Surf. Processes Landforms, 13(4), 355–367.
Church, M., and Ferguson, R. (2015). “Morphodynamics: Rivers beyond steady state.” Water Resour. Res., 51(4), 1883–1897.
Cui, Y., et al. (2003a). “Sediment pulses in mountain rivers. 1: Experiments.” Water Resour. Res., 39(9), 1239.
Cui, Y., and Parker, G. (2005). “Numerical model of sediment pulses and sediment-supply disturbances in mountain rivers.” J. Hydraul. Eng., 646–656.
Cui, Y., Parker, G., Pizzuto, J., and Lisle, T. E. (2003b). “Sediment pulses in mountain rivers. 2: Comparison between experiments and numerical predictions.” Water Resour. Res., 39(9), 1239.
Cui, Y., Wooster, J. K., Venditti, J. G., Dusterhoff, S. R., Dietrich, W. E., and Sklar, L. S. (2008). “Simulating sediment transport in a flume with forced pool-riffle morphology: Examinations of two one-dimensional numerical models.” J. Hydraul. Eng., 892–904.
Darby, S. E., Alabyan, A. M., and Van de Wiel, M. J. (2002). “Numerical simulation of bank erosion and channel migration in meandering rivers.” Water Resour. Res., 38(9), 1–21.
DFAA (Disaster Financial Assistance Arrangements). (2007). “Guidelines for the disaster financial assistance arrangements.” ⟨www.publicsafety.gc.ca/prg/em/res-eng.aspx⟩ (Oct. 15, 2015).
Eaton, B., Church, M., and Ham, D. (2002). “Scaling and regionalization of flood flows in British Columbia, Canada.” Hydrol. Processes, 16(16), 3245–3263.
Emmett, W. W., and Wolman, M. G. (2001). “Effective discharge and gravel-bed rivers.” Earth Surf. Processes Landforms, 26(13), 1369–1380.
Ferguson, R. (2007). “Flow resistance equations for gravel-and boulder-bed streams.” Water Resour. Res., 43(5), W05427.
Ferguson, R. I. (1986). “Hydraulics and hydraulic geometry.” Progress Phys. Geogr., 10(1), 1–31.
Ferguson, R. I. (2012). “River channel slope, flow resistance, and gravel entrainment thresholds.” Water Resour. Res., 48(5), W05517.
Galay, V., Yaremko, E., and Quazi, M. (1987). “River bed scour and construction of stone riprap protection.” Sediment transfer in gravel-bed rivers, Wiley, New York.
Harvey, A. M., Mather, A. E., and Stokes, M. (2005). “Alluvial fans: geomorphology, sedimentology, dynamics—Introduction: A review of alluvial-fan research.” Geol. Soc. London. Spec. Publ., 251(1), 1–7.
Hijmans, R. J. (2015). “Raster: Geographic data analysis and modeling.” ⟨http://CRAN.R-project.org/package=raster⟩ (Sep. 7, 2015).
Hooke, R. L. (1967). “Processes on arid-region alluvial fans.” J. Geol., 75(4), 438–460.
Huebl, J., and Fiebiger, G. (2005). “Debris-flow mitigation measures.” Debris-flow hazards and related phenomena, Springer, Berlin, 445–487.
Humphries, R., Venditti, J. G., Sklar, L. S., and Wooster, J. K. (2012). “Experimental evidence for the effect of hydrographs on sediment pulse dynamics in gravel-bedded rivers.” Water Resour. Res., 48(1), W01533.
Jakob, M., Clague, J. J., and Church, M. (2016). “Rare and dangerous: Recognizing extra-ordinary events in stream channels.” Can. Water Resour. J., 41(1–2), 161–173.
Kaufmann, P. R., Faustini, J. M., Larsen, D. P., and Shirazi, M. A. (2008). “A roughness-corrected index of relative bed stability for regional stream surveys.” Geomorphology, 99(1), 150–170.
Kellerhals, R., Church, M., and Bray, D. I. (1976). “Classification and analysis of river processes.” J. Hydraul. Div., 102, 813–829.
Knighton, A. D., and Nanson, G. C. (1993). “Anastamosis and the continuum of channel pattern.” Earth Surf. Processes Landforms, 18(7), 613–625.
Lacey, G. (1930). “Stable channels in alluvium.” Minutes of the Proc. Institution of Civil Engineers, Vol. 229, Thomas Telford, London, 259–292.
Lamb, M. P., Dietrich, W. E., and Venditti, J. G. (2008). “Is the critical Shields stress for incipient sediment motion dependent on channel-bed slope?” J. Geophys. Res., 113(F2), F02008.
Lisle, T. E., Cui, Y., Parker, G., Pizzuto, J. E., and Dodd, A. M. (2001). “The dominance of dispersion in the evolution of bed material waves in gravel-bed rivers.” Earth Surf. Processes Landforms, 26(13), 1409–1420.
Madej, M. A., and Ozaki, V. (1996). “Channel response to sediment wave propagation and movement, Redwood Creek, California, USA.” Earth Surf. Processes Landforms, 21(10), 911–927.
Madej, M. A., Sutherland, D. G., Lisle, T. E., and Pryor, B. (2009). “Channel responses to varying sediment input: A flume experiment modeled after Redwood Creek, California.” Geomorphology, 103(4), 507–519.
Malverti, L., Lajeunesse, E., and Mtivier, F. (2008). “Small is beautiful: Upscaling from microscale laminar to natural turbulent rivers.” J. Geophys. Res., 113(4), F04004.
Midgley, T. L., Fox, G. A., and Heeren, D. M. (2012). “Evaluation of the bank stability and toe erosion model (BSTEM) for predicting lateral retreat on composite streambanks.” Geomorphology, 145, 107–114.
Montgomery, D. R. (1999). “Process domains and the river continuum.” J. Am. Water Resour. Assoc., 35(2), 397–410.
Montgomery, D. R., and Buffington, J. M. (1997). “Channel-reach morphology in mountain drainage basins.” Geol. Soc. Am. Bull., 109(5), 596–611.
Nays2DH [Computer software]. U.S. Geological Survey, Reston, VA.
Neil, C. (1964). “River bed scour: A review for bridge engineers, contract no. 281.” Research Council of Alberta, Calgary, Alberta, Canada.
Olsen, D., Whitaker, A., and Potts, D. (1997). “Assessing stream channel stability thresholds using flow competence estimates at bankfull stage.” Water Resour. Bull., 33(6), 1197–1207.
Peakall, J., Ashworth, P., and Best, J. L. (1996). “Physical modelling in fluvial geomorphology: Principles applications and unresolved issues.” Scientific Nature of Geomorphology: Proc., 27th Binghamton Symp. in Geomorphology, Wiley, New York, 221–253.
Phillips, J. D. (2002). “Geomorphic impacts of flash flooding in a forested headwater basin.” J. Hydrol., 269(3), 236–250.
Pickup, G., and Warner, R. F. (1976). “Effects of hydrologic regime on magnitude and frequency of dominant discharge.” J. Hydrol., 29(1/2), 51–75.
Prancevic, J. P., and Lamb, M. P. (2015). “Unraveling bed slope from relative roughness in initial sediment motion.” J. Geophys. Res. Earth Surf., 120(3), 474–489.
R Core Team. (2015). R: A language and environment for statistical computing, R Foundation for Statistical Computing, Vienna, Austria.
Recking, A. (2009). “Theoretical development on the effects of changing flow hydraulics on incipient bed load motion.” Water Resour. Res., 45(4), W04401.
Roberts, R. G., and Church, M. (1986). “The sediment budget in severely disturbed watersheds, Queen Charlotte ranges, British Columbia.” Can. J. Forest Res., 16(5), 1092–1106.
Rosgen, D. L. (1994). “A classification of natural rivers.” Catena, 22(3), 169–199.
Venditti, J. G., Dietrich, W. E., Nelson, P. A., Wydzga, M. A., Fadde, J., and Sklar, L. (2010). “Effect of sediment pulse grain size on sediment transport rates and bed mobility in gravel bed rivers.” J. Geophys. Res., 115(3), F03039.
Wilcock, P. R., and Crowe, J. C. (2003). “Surface-based transport model for mixed-size sediment.” J. Hydraul. Eng., 120–128.
Wilcock, P. R., and McArdell, B. W. (1993). “Surface-based fractional transport rates: Mobilization thresholds and partial transport of a sand-gravel sediment.” Water Resour. Res., 29(4), 1297–1312.
Wilcock, P. R., and McArdell, B. W. (1997). “Partial transport of a sand/gravel sediment.” Water Resour. Res., 33(1), 235–245.
Wilford, D. J., Sakals, M. E., Innes, J. L., Sidle, R. C., and Bergerud, W. A. (2004). “Recognition of debris flow, debris flood and flood hazard through watershed morphometrics.” Landslides, 1(1), 61–66.
Yalin, S. M. (1971). “Theory of hydraulic models.” MacMillan, London.
Yaremko, E., and Cooper, R. (1983). “Influence of northern pipelines on river crossing design.” Pipelines in adverse environments II, ASCE, Reston, VA, 49–63.
Zimmermann, A. E., Church, M., and Hassan, M. A. (2008). “Identification of steps and pools from stream longitudinal profile data.” Geomorphology, 102(3), 395–406.
Zollinger, F. (1985). “Debris detention basins in the European Alps.” Int. Symp. on Erosion, Debris Flow and Disaster Prevention, Erosion Control Engineering Society, Tsukuba, Japan, 433–438.
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Journal of Hydraulic Engineering
Volume 143 • Issue 8 • August 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Feb 9, 2016
Accepted: Jan 9, 2017
Published ahead of print: Mar 30, 2017
Published online: Mar 31, 2017
Published in print: Aug 1, 2017
Discussion open until: Aug 31, 2017
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