Description
Return channel/valley, channel/straight, and valley/straight ratios.
Geomorphic geometry uses lengths, areas, volumes, and dimensionless shape ratios to summarize a feature. Grain axes, channel dimensions, and angular units need explicit definitions because similar field names can describe different measurements.
Return channel/valley, channel/straight, and valley/straight ratios.
When to use this tool
Use Channel Sinuosity Valley Reference Ratio when you need a geometric summary of a supplied landform or sediment measurement.
How to use the tool and how it works
- Enter channelLength, valleyLength, straightDistance. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read valleySinuosity, directSinuosity, valleyTortuosity. Use the output convention below.
Require positive straightDistance, valleyLength at least straight distance, and channelLength at least valley length. Return channel/valley, channel/straight, and valley/straight ratios.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| channelLength | Channel Length | Required. Finite number. |
| valleyLength | Valley Length | Required. Finite number. |
| straightDistance | Straight Distance | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| valleySinuosity | Valley Sinuosity | Required. Finite number. |
| directSinuosity | Direct Sinuosity | Required. Finite number. |
| valleyTortuosity | Valley Tortuosity | Required. Finite number. |
{
"input": {
"channelLength": 150,
"valleyLength": 120,
"straightDistance": 100
},
"output": {
"valleySinuosity": 1.25,
"directSinuosity": 1.5,
"valleyTortuosity": 1.2
}
}Limitations and assumptions
- All lengths share units and endpoints; the denominators differ and the supplied ratios do not establish a particular channel process or stability class.
- 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
Inspect the measured feature and sampling method for the intended geometric definition. Use a spatial model or complete distribution when a single shape ratio or local term is insufficient.
References
Similar or alternative tools
- Channel Sinuosity Distance Factor
Return channel/valley sinuosity and channel-valley excessLength.
- Relief Ratio Basin Length Term
Return relief and relief/basinLength.