Model name | Abbreviation | Equation | Fitting parameters |
Five parameter models | |||
Van Genuchten | VG1 |
| θr, θs, α, n, m |
Fredlund-Xing | FX |
| θr, θs, α, n, m |
Omuto | Omuto |
| θr, θs1, θs2, α1, α2 |
Four-parameter models | |||
Gardner | Gard |
| θr, θs, α, n |
Brooks-Corey | BC |
| θr, θs, α, n |
Kosugi | Kosugi | , Q is complimentary normal distribution function define as
| θr, θs, α, n |
Double exponential | Dexpo |
| θs1, θs2, α1, α2 |
Van Genuchten | VG2 |
| θr, θs, α, n |
Russo | Ruso |
| θr, θs, α, n |
Three-parameter models | |||
McKee-Bumb | MB |
| θr, θs, α |
Campbell | Camp |
| θs, α, n |
Tani | Tani |
| θr, θs, α |