Infiltration, runoff and erosion models

Infiltration: Horton (1940), Philip (1957) and Green and Ampt (1911) rates and cumulative depths. ScsRunoff: SCS curve-number runoff and runoff coefficient (USDA-SCS 1972). Rusle: \(A = R K LS C P\) with the Wischmeier and Smith (1978) LS factor.

Usage

Infiltration(
  t,
  model = "horton",
  f0 = NULL,
  fc = NULL,
  k = NULL,
  S = NULL,
  A = NULL,
  Ks = NULL,
  psi = NULL,
  dtheta = NULL
)

ScsRunoff(P, CN, ia_ratio = 0.2)

Rusle(R, K, C, P, slope_length, slope_pct)

Arguments

t

Times.

model

"horton", "philip" or "green_ampt".

f0, fc, k

Horton parameters.

S, A

Philip sorptivity and transmissivity.

Ks, psi, dtheta

Green-Ampt conductivity, wetting-front suction and moisture deficit.

P

Rainfall (mm) or, for Rusle, the support practice factor.

CN

Curve number.

ia_ratio

Initial abstraction ratio.

R, K, C

RUSLE factors.

slope_length

Slope length (m).

slope_pct

Slope (percent).

Value

List.

References

Green, W. H. and Ampt, G. A. (1911). Studies on soil physics. Journal of Agricultural Science 4, 1-24.

Wischmeier, W. H. and Smith, D. D. (1978). Predicting Rainfall Erosion Losses. USDA Agriculture Handbook 537.

Examples

Infiltration(1, "horton", f0 = 10, fc = 2, k = 1)$rate
#> [1] 4.943036
ScsRunoff(50, 80)$runoff
#> [1] 13.80248
Rusle(100, 0.3, 0.2, 1, slope_length = 22.13, slope_pct = 9)$LS
#> [1] 0.9993118