Soil data

Soil layers

Soil layer thickness is globally defined with the parameter i_delz, or in the file soilprofile.par for each soil layer separately. The sum of the soil layers need to be equal to the topographical parameter i_cz (maximum elevation). The VOM will raise a warning and correct i_cz if this is not the case. The river bed level i_zr needs to align with the soil layers. Also here, the VOM will give a warning and correct i_zr if needed.

Soil properties

Soil water retention and hydraulic conductivity parameters for 12 major soil textural groups according to [1]. Some units of the parameters (alpha and Ksat) are converted for the use in the VOM.

Texture theta-r theta-s alpha (1/m) n K-sat (m/s)
Sand 0.045 0.43 14.5 2.68 8.25*10-5
Loamy Sand 0.057 0.41 12.4 2.28 4.053*10-5
Sandy Loam 0.065 0.41 7.5 1.89 1.228*10-5
Loam 0.078 0.43 3.6 1.56 2.889*10-6
Silt 0.034 0.46 1.6 1.37 6.944*10-7
Silt Loam 0.067 0.45 2.0 1.41 1.25*10-6
Sandy Clay Loam 0.100 0.39 5.9 1.48 3.639*10-6
Clay Loam 0.095 0.41 1.9 1.31 7.222*10-7
Silty Clay Loam 0.089 0.43 1.0 1.23 1.944*10-7
Sandy Clay 0.100 0.38 2.7 1.23 3.333*10-7
Silty Clay 0.070 0.36 0.5 1.09 5.555*10-8
Clay 0.068 0.38 0.8 1.09 5.555*10-7
[1]Carsel, R.F. & R.S.Parrish (1988): Developing joint probability distributions of soil water retention characteristics.-Water Resource Research 24:755-769.