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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.

Shreve R. 1974. Variation of mainstream length with basin area in river networks. Water Resources Research, 10, p. 1167-1177.

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.

River network order

Strahler, Shreve, Horton, Scheidegger
order"

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.

2 st_codecsp (ers[ers$up_catchment_area>40000,"st_codecsp"]) : 06840051, 0547C025

In blue : BDCarthage In red : CCM
Point 06840051
The join is good between the CCM and BDMAP, maybe it's the largeurlameau which is wrong.

Point 0547C025
No match with the CCM layer, we can delete this point

Model with and without these points