UBCRM: The UBC Regime Model
The UBC Regime model has been developed over a number of years as a collaboration between researchers in the Department of Civil Engineering and the Department of Geography at the University of BC.
The model is based on the understanding that a simple model with modest data requirements is more likely to be useful than a data intensive, numerically demanding one, especially for environmental practitioners. While simple, the model does consider the relevant controlling factors, the most important of which is the nature and erodibility of the channel banks.
The goal of our research on this topic is to determine which simplifying assumptions about river channel behaviour are reasonable to make, and to identify the underlying physical processes.
Mike Church
Geography Dept.
mchurch at geog ubc ca
With his focus on the physics of stream channel behaviour, Mike has kept this project on sound scientific ground by emphasizing the role of flow resistance adjustments as a stabilizing process
Brett Eaton
Geography Dept.
brett.eaton at ubc ca
Brett has been working on comparisons of the model against data from the field and from lab experiments,
& identifying the feedback mechanisms that produce morphologic stability in rivers
Rob Millar
Civil Engineering Dept.
millar at civil ubc ca
Rob is the original creator of the UBC regime model, and developed the concept of ‘optimality theory’, as well as a practical bank strength formulation for the model
Rational regime theories relating stream channel conditions to the external driving forces have a long history. There are two main impediments to the general acceptance of rational regime models: the first is the development of a scientifically reasonable understanding of the extremal hypotheses used in the models; and the second is the incorporation of a bank stability analysis in the model. Researchers at UBC (including M. Church, B. Eaton, R. Millar, M. Quick) have made significant progress on these two issues. We have been able to re-formulate the extremal hypotheses in such a way as to make the underlying principle more easily understood. We have actually tested this principle against observed channel adjustments in the laboratory, where we have observed behaviour that is consistent with our generalized extremal hypothesis. We have also incorporated various bank strength formulations into the regime model which results in a general agreement between model predictions and observed channel dimensions, overcoming the long-standing criticism that regime models consistently under-predict channel width. The regime model is gaining recognition, and was awarded the Wiley Award by the British Geomorphological Research Group for best paper in ESPL for 2004/05. It is now being tested by various environmental consultants in BC who are looking for practical tools for making better decisions about stream channel management. We believe that there are numerous research applications for this model as well, including the replacement of arbitrary and theoretically meaningless hydraulic geometry equations in numerical models of downstream sediment transfer and longitudinal profile evolution, landscape evolution, etc. The following references present the intellectual basis from which the UBC Regime Model has evolved.
Yang CT. 1976. Minimum unit stream power and fluvial hydraulics. Journal of the Hydraulics Division, Proceedings of the American Society of Civil Engineers 102: 769–784.
Kirkby MJ. 1977. Maximum sediment efficiency as a criterion for alluvial channels. In River Channel Changes, Gregory KJ (ed.). John Wiley: Chichester; 429–442.
Chang HH. 1979. Minimum stream power and river channel patterns. Journal of Hydrology 41: 303–327.
White WR, Bettess R, Paris E. 1982. Analytical approach to river regime. Journal of the Hydraulics Division, Proceedings of the American Society of Civil Engineers 108: 1179–1193.
Davies TRH, Sutherland AJ. 1983. Extremal hypotheses for river behavior. Water Resources Research 19(1): 141–148.
Ferguson R. 1987. Hydraulic and sedimentary controls of channel pattern. In Rivers – Environment, Process and Form, Richards K. (ed.). Special Publication. Institute of British Geographers. 129–158.
REFERENCES FOR THE UBC REGIME MODEL:
The following references present some of the key work that has been done during the development and testing of the UBC regime model. There are also other, related papers on the UBC Model, which can be found from the home pages of Dr. Eaton and Dr. Millar.
Eaton BC, Church M. 2007. Predicting downstream hydraulic geometry: a test of rational regime theory. Journal of Geophysical Research - Earth Surface. 112, F03025, doi:10.1029/2006JF000734.
Eaton BC. 2006. Bank stability analysis for regime models of vegetated gravel bed rivers. Earth Surface Processes and Landforms, 31: 1438 - 1444.
Eaton BC, Church M, Davies TRH. 2006. A conceptual model for meander initiation in bedload dominated streams. Earth Surface Processes and Landforms, 31: 875 - 891.
Millar RG. 2005. Theoretical regime equations for mobile gravel-bed rivers with stable banks. Geomorphology 64: 207-220.
Eaton BC, Millar RG. 2004. Optimal alluvial channel width under a bank stability constraint. Geomorphology, 62: 35-45.
Eaton BC, Church M, Millar RG. 2004. Rational regime model of alluvial channel morphology and response. Earth Surface Processes and Landforms, 29: 511-529.
Millar, RG. 2000. Influence of bank vegetation on alluvial channel patterns. Water Resources Research 36:1109-1118.
Millar, RG. 2000. Influence of bank vegetation on alluvial channel patterns. Water Resources Research 36:1109-1118.
Millar RG, Quick MC. 1998. Stable width and depth of gravel-bed rivers with cohesive banks. Journal of Hydraulic Engineering 124(10): 1005–1013.
Millar RG, Quick MC. 1993. Effect of bank stability on geometry of gravel rivers. Journal of Hydraulic Engineering 119(12): 1343–1363.
There are two versions of the program. The program using the bank stability analysis of Millar and Quick (1993) is called the UBCRM model. The program using the bank stability analysis presented in Eaton (2006) is call the UBCRM_H model.
The Development Team
History & References