D-infinity and multiple flow direction routing

DinfFlowDirection: steepest facet direction (radians counter-clockwise from east; Tarboton 1997). MfdFlowAccumulation: Freeman (1991) multiple flow direction, shares \(\propto (\tan\beta_k)^p\).

Usage

DinfFlowDirection(dem, res = 1)

MfdFlowAccumulation(dem, res = 1, p = 1.1)

Arguments

dem

Elevation matrix.

res

Cell size.

p

Exponent.

Value

Matrix.

References

Tarboton, D. G. (1997). A new method for the determination of flow directions and upslope areas in grid digital elevation models. Water Resources Research 33, 309-319.

Freeman, T. G. (1991). Calculating catchment area with divergent flow based on a regular grid. Computers and Geosciences 17, 413-422.

Examples

DinfFlowDirection(rbind(c(3, 3, 3), c(2, 2, 2), c(1, 1, 1)))
#>      [,1]     [,2] [,3]
#> [1,]  NaN      NaN  NaN
#> [2,]  NaN 4.712389  NaN
#> [3,]  NaN      NaN  NaN
MfdFlowAccumulation(rbind(c(2, 1), c(1, 0)))
#>          [,1]     [,2]
#> [1,] 1.000000 1.288676
#> [2,] 1.288676 4.000000