Knudsen Relationship Flow Ratio
Solve steady two-layer Knudsen volume/salt balances including nonzero river salinity, excluding evaporation/storage; salinities must share the same conservative concentration basis.
Description
A steady two-layer estuary exchanges volume and salt with the ocean.
A steady two-layer estuary exchanges volume and salt with the ocean. Nonzero river salinity changes the required exchange.
Solve steady two-layer Knudsen volume/salt balances including nonzero river salinity, excluding evaporation/storage; salinities must share the same conservative concentration basis.
When to use Knudsen Relationship Flow Ratio
Use this tool to solve steady two-layer Knudsen volume/salt balances including nonzero river salinity, excluding evaporation/storage; salinities must share the same conservative concentration basis.
Gather the water, wave, current or profile observations and any supplied calibration constants. Confirm units and the stated coordinate and pressure conventions.
How to use Knudsen Relationship Flow Ratio and understand its results
- Gather the water, wave, current or profile observations and any supplied calibration constants. Confirm units and the stated coordinate and pressure conventions.
- Enter riverInflowM3PerSecond, riverSalinity, inflowingOceanSalinity, outflowingEstuarySalinity using the field table and calculation rules, then run the tool.
- Read oceanInflowM3PerSecond, estuaryOutflowM3PerSecond, saltBalanceResidualSalinityM3PerSecond. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| riverInflowM3PerSecond | River inflow m3 per second | number | Required |
| riverSalinity | River salinity | number | Required |
| inflowingOceanSalinity | Inflowing ocean salinity | number | Required |
| outflowingEstuarySalinity | Outflowing estuary salinity | number | Required |
Use nonnegative flow and salinities satisfying river ≤ estuary outflow < ocean inflow. Add river and ocean inflows for outflow and report the signed salt-balance residual.1
ocean inflow = river flow × (outflow salinity−river salinity)/(ocean salinity−outflow salinity) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| oceanInflowM3PerSecond | Ocean inflow m3 per second | number |
| estuaryOutflowM3PerSecond | Estuary outflow m3 per second | number |
| saltBalanceResidualSalinityM3PerSecond | Salt balance residual salinity m3 per second | number |
{
"input": {
"riverInflowM3PerSecond": 10,
"riverSalinity": 1,
"inflowingOceanSalinity": 35,
"outflowingEstuarySalinity": 20
},
"output": {
"oceanInflowM3PerSecond": 12.666666666666666,
"estuaryOutflowM3PerSecond": 22.666666666666664,
"saltBalanceResidualSalinityM3PerSecond": 5.684341886080802e-14
}
}Limitations and assumptions
Evaporation and storage are excluded; salinities need one conservative basis.
Numbers and computed results must be finite; overflow produces an error. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Salt Wedge Intrusion Length: Fit an exponential salt-intrusion profile and locate a caller salinity crossing, explicitly flagging extrapolation; not a salt-wedge hydraulics solution or freshwater-use guarantee. For a complementary task, use Estuary Stratification Numeration Classifier: Screen river buoyancy versus tidal stirring with an estuarine Richardson-number convention and caller regimes; depth cancels in this convention, not a universal mixing classifier.
References
-
Knudsen Relationship Flow Ratio — tool.io
Similar or alternative tools
- Salt Wedge Intrusion Length
Fit an exponential salt-intrusion profile and locate a caller salinity crossing, explicitly flagging extrapolation; not a salt-wedge hydraulics solution or freshwater-use guarantee.
- Estuary Stratification Numeration Classifier
Screen river buoyancy versus tidal stirring with an estuarine Richardson-number convention and caller regimes; depth cancels in this convention, not a universal mixing classifier.