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ptfkit.wang2012

ptfkit.wang2012

Wang et al. (2012), surface loess across China's Loess Plateau.

Reference

Wang, Y. Q., Shao, M. A., & Liu, Z. P. (2012). Pedotransfer functions for predicting soil hydraulic properties of the Chinese Loess Plateau. Soil Science, 177, 424-432. DOI: 10.1097/SS.0b013e318255a449

Territory

Surface soils across the entire Loess Plateau, China

Dataset

382 surface (0-5 cm) sites; 252 derivation and 130 validation data sets.

CLASS DESCRIPTION
Wang2012PTFResult

Results returned by the matching PTF.
FUNCTION DESCRIPTION
calc_ptf_wang2012

Estimate saturated water content, field capacity, and saturated conductivity.

Wang2012PTFResult

Bases: NamedTuple, Generic[T]

Results returned by the matching PTF.

ATTRIBUTE DESCRIPTION
theta_s

Saturated volumetric water content normalized from the regression's volume-percent scale. (cm^3/cm^3)

TYPE: T

theta_fc

Volumetric water content at -33 kPa normalized from the regression's volume-percent scale. (cm^3/cm^3)

TYPE: T

k_sat

Saturated hydraulic conductivity converted from cm/day. (m/s)

TYPE: T

Source code in ptfkit/wang2012.py 
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class Wang2012PTFResult(NamedTuple, Generic[T]):
    """Results returned by the matching PTF.

    Attributes:
        theta_s: Saturated volumetric water content normalized from the regression's volume-percent
            scale. (cm^3/cm^3)
        theta_fc: Volumetric water content at -33 kPa normalized from the regression's
            volume-percent scale. (cm^3/cm^3)
        k_sat: Saturated hydraulic conductivity converted from cm/day. (m/s)

    """

    theta_s: T
    theta_fc: T
    k_sat: T

calc_ptf_wang2012 

calc_ptf_wang2012(*, sand: float, silt: float, clay: float, bulk_density: float, soil_organic_carbon: float, altitude: float) -> Wang2012PTFResult[floating]

calc_ptf_wang2012(*, sand: ArrayLike, silt: ArrayLike, clay: ArrayLike, bulk_density: ArrayLike, soil_organic_carbon: ArrayLike, altitude: ArrayLike, out: Wang2012PTFResult[NDArray[floating]] | None = None) -> Wang2012PTFResult[NDArray[floating]]

Estimate saturated water content, field capacity, and saturated conductivity.

PARAMETER DESCRIPTION
sand

Sand content, 0.05-1 mm. (%)

TYPE: float | ArrayLike

silt

Silt content, 0.002-0.05 mm. (%)

TYPE: float | ArrayLike

clay

Clay content, <0.002 mm. (%)

TYPE: float | ArrayLike

bulk_density

Bulk density. (g/cm^3)

TYPE: float | ArrayLike

soil_organic_carbon

Soil organic carbon exposed by the public API as percent by mass. (%)

TYPE: float | ArrayLike

altitude

Altitude above sea level. (m)

TYPE: float | ArrayLike

out

Optional output arrays for in-place calculation.

TYPE: Wang2012PTFResult[NDArray[floating]] | None DEFAULT: None

RETURNS DESCRIPTION
Wang2012PTFResult

Results grouped by result attributes.

TYPE: Wang2012PTFResult[floating] | Wang2012PTFResult[NDArray[floating]]

Models

\(h(\theta)\): Point estimates at saturation and -33 kPa \(k(h)\): Saturated hydraulic conductivity

Notes

Prediction target: Saturated soil-water content, water content at -33 kPa, and saturated hydraulic conductivity. The regression uses source SOC in g/kg; the public API accepts percent. Base-10 logarithms reproduce the source's raw and transformed Ks ranges. Water-content equations are evaluated in percentage points and divided by 100 for public volumetric fractions.

Warning

This normalization intentionally changes the legacy water-content outputs by a factor of 100.

Source code in ptfkit/wang2012.py 
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def calc_ptf_wang2012(
    *,
    sand: float | ArrayLike,
    silt: float | ArrayLike,
    clay: float | ArrayLike,
    bulk_density: float | ArrayLike,
    soil_organic_carbon: float | ArrayLike,
    altitude: float | ArrayLike,
    out: Wang2012PTFResult[NDArray[floating]] | None = None,
) -> Wang2012PTFResult[floating] | Wang2012PTFResult[NDArray[floating]]:
    r"""Estimate saturated water content, field capacity, and saturated conductivity.

    Arguments:
        sand: Sand content, 0.05-1 mm. (%)
        silt: Silt content, 0.002-0.05 mm. (%)
        clay: Clay content, <0.002 mm. (%)
        bulk_density: Bulk density. (g/cm^3)
        soil_organic_carbon: Soil organic carbon exposed by the public API as percent by mass. (%)
        altitude: Altitude above sea level. (m)
        out: Optional output arrays for in-place calculation.

    Returns:
        Wang2012PTFResult: Results grouped by result attributes.

    Models:
        $h(\theta)$: Point estimates at saturation and -33 kPa
        $k(h)$: Saturated hydraulic conductivity

    Notes:
        Prediction target: Saturated soil-water content, water content at -33 kPa, and saturated
            hydraulic conductivity.
        The regression uses source SOC in g/kg; the public API accepts percent.
        Base-10 logarithms reproduce the source's raw and transformed Ks ranges.
        Water-content equations are evaluated in percentage points and divided by 100 for public
            volumetric fractions.

    Warning:
        This normalization intentionally changes the legacy water-content outputs by a factor of
            100.

    """
    values = _call(
        _calc_ptf_wang2012,
        sand,
        silt,
        clay,
        bulk_density,
        soil_organic_carbon,
        altitude,
        out=out,
    )

    return Wang2012PTFResult(*values)