Description
Convert supplied dry-basis gravimetric water ratio to a volumetric fraction.
Soil and traction calculations depend on dry-mass versus wet-mass moisture bases, density units, layer thickness and distance conventions. Volumetric water fraction requires dry bulk density, while a single height residual differs from a roughness statistic. Supplied scalar relations do not establish physical plausibility or soil condition.
Convert supplied dry-basis gravimetric water ratio to a volumetric fraction.
When to use this tool
Use Soil Water Gravimetric Volumetric Point when you already have gravimetricWaterFraction, dryBulkDensity, waterDensity and need to convert supplied dry-basis gravimetric water ratio to a volumetric fraction.
How to use the tool and how it works
- Enter gravimetricWaterFraction, dryBulkDensity, waterDensity. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read volumetricWaterFraction. Use the output convention below.
Require gravimetricWaterFraction/dryBulkDensity>=0 and waterDensity>0; return gravimetric ratio*dry bulk density/water density.1
Dry bulk density links dry-basis gravimetric water content to volumetric water content through the water density. The relevant densities and site-specific measurement basis must be supplied consistently.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| gravimetricWaterFraction | Water mass/dry soil mass, not wet-mass moisture fraction. | Required. Finite number; minimum 0. |
| dryBulkDensity | Dry soil mass/bulk soil volume, in the same density unit as waterDensity. | Required. Finite number; minimum 0. |
| waterDensity | Water Density | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| volumetricWaterFraction | Gravimetric ratio*dryBulkDensity/waterDensity; values above one are not rejected as physically implausible. | Required. Finite number. |
{
"input": {
"gravimetricWaterFraction": 0.2,
"dryBulkDensity": 1.5,
"waterDensity": 1
},
"output": {
"volumetricWaterFraction": 0.30000000000000004
}
}Limitations and assumptions
- Gravimetric ratio is water mass/dry soil mass, not wet-mass moisture fraction. Densities need the same unit; values above one are accepted without a physical plausibility check, porosity or soil state inference.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use complete calibrated measurements, sampling design and physical models. Review density, moisture, heat and traction assumptions before interpreting local fractions or residuals as field performance or appropriate management.
References
-
Calculation and input contract: agrophysics/soil-water-gravimetric-volumetric-point — tool.io
-
Calibrating Soil-Water Measuring Devices — North Carolina State University Extension
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