Decrease stage values in river cells if they are implausible with respect to water always flowing downhill.
BumpRiverStage(r, outlets, min.drop = 1e-06)'RasterLayer'. Numeric cell values representing river stages.
'SpatialPoints*', 'SpatialLines*', 'SpatialPolygons*' or 'Extent'.
Designates the location of discharge outlets.
The rasterize function is used to locate outlet cells in the raster grid r.
'numeric' number. Minimum drop in stage between adjacent river cells.
An object of class 'RasterLayer' with cell values representing the vertical change in stream stage.
These changes can be added to r to ensure that water always flows downhill.
The Lee algorithm (Lee, 1961) is used to identify flow paths among the modeled river cells. An analysis of river cell stage values along a flow path identifies any problematic cells that are obstructing downhill surface-water flow. Stage values for these problematic cells are then lowered to an acceptable elevation.
Lee, C.Y., 1961, An algorithm for path connections and its applications: IRE Transactions on Electronic Computers, v. EC-10, no. 2, p. 346--365.