back to first page ..

The objective is to compute river width on each node of a river network. The principle is to link width measured during electro-fishing operations (and available in BDMAP) with a proxy which allows a generalisation to a river network.

Usually , river width is connected to river discharge with a square-root link (Leopold et Maddock 1953; Andrews 1984; Julien and Wargadalam 1995; Jiongxin 2004; Lee and Julien 2006; Caissie 2006. The river discharge is more or less proportional to streaming surface although allometric relationships shown some regional variations (Benyahya et al., 2009). Thornton et al. (2007) found a direct square-root relationship between river width and upstream streaming surface.

Benyahya, L., A. Daigle, et al. (2009). Caractérisation du régime naturel du débit des bassins versants de l’Est du Canada., INRS-ETE: 88

Caissie, D. (2006). River discharge and channel width relationships for New Brunswick rivers, Canadian technical report of fisheries and aquatic sciences/Rapport technique canadien des sciences halieutiques et aquatiques: 26

Jiongxin, X. (2004). "Comparison of hydraulic geometry between sand- and gravel-bed rivers in relation to channel pattern discrimination." Earth Surface Processes and Landforms 29(5): 645-657

Julien, P. Y. and J. Wargadalam (1995). "Alluvial Channel Geometry: Theory and Applications." Journal of Hydraulic Engineering 121(4): 312-325.

Lee, J.-S. and P. Y. Julien (2006). "Downstream hydraulic geometry of alluvial channels." Journal of Hydraulic Engineering 132(12): 1347-1352.

Leopold, L. B. and T. Maddock (1953). The hydraulic geometry of stream channels and some physiographic implications. Washington, DC, U.S. Geological Survey Professional Paper: 57.

Thornton, E., M. Neave, et al. (2007). Hydraulic geometry in river channel networks as a method for the assessment of river condition. Proceedings of the 5th Australian Stream Management Conference. Australian rivers: making a difference., Thurgoona, New South Wales., Charles Sturt University.

Problems in the model

Some data are very strange
2 points with an up_catchment_area >40000 and a st_cs_largeurlameeau very small (<15).
View with the up_catchment area >40000 - they correspond to the riversegement with the maximal higth, so the problems don't come from the calculation of the up_catchment_area, but when we join the CCM layer and the BDMAP points.