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Cosby et al. (1984), United States.

Source

Cosby, B. J., Hornberger, G. M., Clapp, R. B., & Ginn, T. R. (1984). A statistical exploration of the relationships of soil moisture characteristics to the physical properties of soils. Water Resources Research, 20(6), 682-690.

Scope

Territory: United States

Dataset: 1448 soil samples from Holtan et al. (1968) and Rawls et al. (1976).

Functions

calc_ptf_cosby1984_univariate

Estimate Cosby et al. (1984) univariate hydraulic parameter statistics from soil texture.

Status: implemented

Prediction target: Mean and standard deviation estimates for hydraulic parameters from sand, silt, and clay percentages.

Models: \(h(\theta)\) — Power function moisture characteristic; \(k(h)\) — Saturated hydraulic conductivity parameter statistics

Inputs

Name Type Unit Domain Description
sand number % 0 <= value <= 100 Sand content.
silt number % 0 <= value <= 100 Silt content.
clay number % 0 <= value <= 100 Clay content.

Outputs

Name Unit Domain Description
mean_b dimensionless Mean slope of the moisture characteristic.
mean_log_psi_s reported log value Mean log saturation matric potential; the underlying potential is expressed in cm H2O.
mean_log_k_sat reported log value Mean log saturated hydraulic conductivity; the underlying conductivity is expressed in inches per hour.
mean_theta_s % volume/volume Mean saturated water content.
sd_b dimensionless Standard deviation of b.
sd_log_k_sat reported log value Standard deviation of log saturated hydraulic conductivity.
sd_theta_s % volume/volume Standard deviation of saturated water content.

Note

No back-transform is applied to logarithmic outputs.

Note

Public API names are provisional for pilot testing.

Warning

Log-transformed output units use the pilot contract reported log value.