Soil params

Root Distribution by Soil Layer

Gale, M. R., & Grigal, D. F. (1987). Vertical root distributions of northern tree species in relation to successional status. Canadian Journal of Forest Research, 17(8), 829-834

The root distribution follows the model of Gale and Grigal (1987), where the cumulative fraction of roots above depth d (in cm) is given by:

Y(d) = 1 − β^d

The fraction of roots within a layer between depths z1 and z2 is then:

rootfr = Y(z2) − Y(z1) = β^z1 − β^z2

Root fraction calculated using Y(d) = 1 − β^d with β = 0.90 (shallow root profile).

Layer	dz (m)	z1 (cm)	z2 (cm)	rootfr	Cumulative rootfr
0	0.05	0.0	5.0	0.410	0.410
1	0.05	5.0	10.0	0.242	0.651
2	0.10	10.0	20.0	0.227	0.878
3	0.10	20.0	30.0	0.079	0.957
4	0.20	30.0	50.0	0.031	0.988
5	0.20	50.0	70.0	0.008	0.995
6	0.20	70.0	90.0	0.003	0.998
7	0.30	90.0	120.0	0.001	0.999
8	0.40	120.0	160.0	0.000	1.000
9	0.40	160.0	200.0	0.000	1.000
10	0.50	200.0	250.0	0.000	1.000

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source

soil_params

def soil_params(
    soil:Soil, # Soil object with the following input attribute:
- texture : int
    Soil texture class:
        1: sand, 2: loamy sand, 3: sandy loam, 4: silt loam,
        5: loam, 6: sandy clay loam, 7: silty clay loam,
        8: clay loam, 9: sandy clay, 10: silty clay, 11: clay
)->Soil: # Updated soil object with the following attributes:
- nlevsoi : int
    Number of soil layers.
- dz : list[float]
    Soil layer thickness (m).
- rootfr : list[float]
    Fraction of roots in each soil layer (-).
- watsat : list[float]
    Soil layer volumetric water content at saturation, i.e. porosity (-).
- psisat : list[float]
    Soil layer matric potential at saturation (mm).
- hksat : list[float]
    Soil layer hydraulic conductivity at saturation (mm H2O/s).
- bsw : list[float]
    Soil layer Clapp and Hornberger "b" parameter (-).

Set soil hydraulic parameters, soil depth, and rooting fraction.

Parameters:

• soil: Soil object with the following input attribute:

  • texture: Soil texture class: 1: sand, 2: loamy sand, 3: sandy loam, 4: silt loam, 5: loam, 6: sandy clay loam, 7: silty clay loam, 8: clay loam, 9: sandy clay, 10: silty clay, 11: clay

Returns:

• soil: Updated Soil object with the following attributes:

  • nlevsoi: Number of soil layers.
  • dz: Soil layer thickness (m).
  • rootfr: Fraction of roots in each soil layer (-).
  • watsat: Soil layer volumetric water content at saturation, i.e. porosity (-).
  • psisat: Soil layer matric potential at saturation (mm).
  • hksat: Soil layer hydraulic conductivity at saturation (mm H2O/s).
  • bsw: Soil layer Clapp and Hornberger “b” parameter (-).

Example soil_params()

soil = Soil()
pprint(vars(soil_params(soil=soil)))

{'bsw': [5.39, 5.39, 5.39, 5.39, 5.39, 5.39, 5.39, 5.39, 5.39, 5.39, 5.39],
 'dz': [0.05, 0.05, 0.1, 0.1, 0.2, 0.2, 0.2, 0.3, 0.4, 0.4, 0.5],
 'h2osoi_vol': [],
 'hksat': [0.0069500000000000004,
           0.0069500000000000004,
           0.0069500000000000004,
           0.0069500000000000004,
           0.0069500000000000004,
           0.0069500000000000004,
           0.0069500000000000004,
           0.0069500000000000004,
           0.0069500000000000004,
           0.0069500000000000004,
           0.0069500000000000004],
 'nlevsoi': 11,
 'psi': [],
 'psisat': [-478, -478, -478, -478, -478, -478, -478, -478, -478, -478, -478],
 'rootfr': [0.40950999999999993,
            0.24181155989999997,
            0.22710178550943075,
            0.07918549631535311,
            0.03723738306789612,
            0.004527196459102321,
            0.0005504014001719315,
            7.2948102027868e-05,
            3.181514910617433e-06,
            4.7025599470265064e-08,
            7.018718816859497e-10],
 'texture': 5,
 'watsat': [0.451,
            0.451,
            0.451,
            0.451,
            0.451,
            0.451,
            0.451,
            0.451,
            0.451,
            0.451,
            0.451]}