Oosterveld and Chang (1980), soil-moisture retention from texture and depth.¶
Source¶
Oosterveld, M., & Chang, C. (1980). Empirical relations between laboratory determinations of soil texture and moisture retention. Canadian Agricultural Engineering, 22, 149-151.
Scope¶
Territory: Southern Alberta, Canada
Dataset: 1,137 pressure-plate analyses on 298 soil samples from the Lethbridge Research Station laboratory; the field-capacity tension regression used 134 samples.
Functions¶
calc_ptf_oosterveld1980_field_capacity_tension¶
Estimate field-capacity tension from clay content.
Status: implemented
Prediction target: Tension at which pressure-plate moisture content equals field capacity determined by the cylinder method.
Models: \(h(\theta)\) — Field-capacity tension point estimate
Inputs¶
| Name | Type | Unit | Domain | Description |
|---|---|---|---|---|
clay | number | % mass | 2 <= value <= 72 | Clay content in percent by weight; the field-capacity tension experiment covered 2% to 72% clay. |
Outputs¶
| Name | Unit | Domain | Description |
|---|---|---|---|
field_capacity_tension | kPa | value > 0 | Predicted tension corresponding to cylinder-method field capacity. |
Note
Equation 1 reports r = 0.67 and n = 134.
calc_ptf_oosterveld1980_retention¶
Estimate gravimetric soil-moisture content from texture, depth, and tension.
Status: implemented
Prediction target: Gravimetric soil-moisture content at a specified tension.
Models: \(h(\theta)\) — Empirical power-law moisture-retention relation
Inputs¶
| Name | Type | Unit | Domain | Description |
|---|---|---|---|---|
clay | number | % mass | — | Clay content in percent by weight. |
sand | number | % mass | — | Sand content in percent by weight. |
mean_depth | number | cm | 8 <= value <= 180 | Mean depth of the soil sample. |
tension | number | kPa | 10 <= value <= 1500 | Soil-moisture tension. |
Outputs¶
| Name | Unit | Domain | Description |
|---|---|---|---|
moisture_content | % mass | — | Predicted soil-moisture content in percent by weight. |
Note
Equation 2 reports r = 0.96 and n = 1,137.
Warning
The paper reports slight inaccuracy at very high clay content and high tension.
calc_ptf_oosterveld1980_field_capacity¶
Estimate gravimetric soil-moisture content at field capacity.
Status: implemented
Prediction target: Gravimetric soil-moisture content at field capacity.
Models: \(h(\theta)\) — Field-capacity point estimate derived from Equations 1 and 2
Inputs¶
| Name | Type | Unit | Domain | Description |
|---|---|---|---|---|
clay | number | % mass | 2 <= value <= 72 | Clay content in percent by weight; the field-capacity tension experiment covered 2% to 72% clay. |
sand | number | % mass | — | Sand content in percent by weight. |
mean_depth | number | cm | 8 <= value <= 180 | Mean depth of the soil sample. |
Outputs¶
| Name | Unit | Domain | Description |
|---|---|---|---|
field_capacity_moisture | % mass | — | Predicted soil-moisture content at field capacity in percent by weight. |
Note
Equation 3 is obtained by substituting the Equation 1 field-capacity tension into Equation 2.
calc_ptf_oosterveld1980_wilting_point¶
Estimate gravimetric soil-moisture content at the 1500 kPa wilting point.
Status: implemented
Prediction target: Gravimetric soil-moisture content at 1500 kPa.
Models: \(h(\theta)\) — Wilting-point estimate at 1500 kPa
Inputs¶
| Name | Type | Unit | Domain | Description |
|---|---|---|---|---|
clay | number | % mass | — | Clay content in percent by weight. |
sand | number | % mass | — | Sand content in percent by weight. |
mean_depth | number | cm | 8 <= value <= 180 | Mean depth of the soil sample. |
Outputs¶
| Name | Unit | Domain | Description |
|---|---|---|---|
wilting_point_moisture | % mass | — | Predicted soil-moisture content at 1500 kPa in percent by weight. |
Note
Equation 4 reports r = 0.96 and n = 298.
Note
The paper takes moisture content at 1500 kPa as the wilting point.
calc_ptf_oosterveld1980_available_water¶
Estimate available gravimetric soil moisture between field capacity and wilting point.
Status: implemented
Prediction target: Difference between gravimetric moisture content at field capacity and at the 1500 kPa wilting point.
Models: \(h(\theta)\) — Available-moisture point estimate from Equations 3 and 4
Inputs¶
| Name | Type | Unit | Domain | Description |
|---|---|---|---|---|
clay | number | % mass | 2 <= value <= 72 | Clay content in percent by weight; the field-capacity tension experiment covered 2% to 72% clay. |
sand | number | % mass | — | Sand content in percent by weight. |
mean_depth | number | cm | 8 <= value <= 180 | Mean depth of the soil sample. |
Outputs¶
| Name | Unit | Domain | Description |
|---|---|---|---|
available_moisture | % mass | — | Predicted field-capacity moisture minus predicted wilting-point moisture, in percentage points by weight. |
Note
The paper defines available soil water by subtracting Equation 4 from Equation 3.