Rainfall Double Mass Slope Ratio Tool

Description

Divide station increments by their reference increments before and after a change.

Precipitation and evaporation records distinguish water depth, catchment area, volume, and observation duration. Converting among them requires coherent units and a clear measured or modeled basis.

Divide station increments by their reference increments before and after a change.

When to use this tool

Use Rainfall Double Mass Slope Ratio when you need one explicit water-depth, volume, or accumulation component.

How to use the tool and how it works

Enter beforeStationIncrement, beforeReferenceIncrement, afterStationIncrement, afterReferenceIncrement. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read slopeBefore, slopeAfter, correctionFactor. Use the output convention below.

Divide station increments by their reference increments before and after a change. Return both slopes and before-slope/after-slope as correctionFactor.^[1]

Input field	Meaning and units	Accepted input
beforeStationIncrement	Before Station Increment	Required. Finite number; minimum 0.
beforeReferenceIncrement	Before Reference Increment	Required. Finite number; strictly above 0.
afterStationIncrement	After Station Increment	Required. Finite number; strictly above 0.
afterReferenceIncrement	After Reference Increment	Required. Finite number; strictly above 0.

Output field	Interpretation	Returned shape
slopeBefore	Slope Before	Required. Finite number.
slopeAfter	Slope After	Required. Finite number.
correctionFactor	Correction Factor	Required. Finite number.

json

{
  "input": {
    "beforeStationIncrement": 80,
    "beforeReferenceIncrement": 100,
    "afterStationIncrement": 60,
    "afterReferenceIncrement": 100
  },
  "output": {
    "slopeBefore": 0.8,
    "slopeAfter": 0.6,
    "correctionFactor": 1.3333333333333335
  }
}

Limitations and assumptions

Reference increments and afterStationIncrement must be positive; beforeStationIncrement may be zero. No change point, homogeneity assessment, or authoritative adjustment is inferred.
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

Check instrument records, unit conversions, temporal coverage, and a complete hydrologic model before interpreting runoff or water availability.

References

Calculation and input contract: hydrology/rainfall-double-mass-slope-ratio — tool.io

Similar or alternative tools

Rainfall Gauge Catch Efficiency Factor
Divide nonnegative collectedDepth by efficiency in (0, 1], then subtract nonnegative referenceDepth.
Gauge Undercatch Supplied Wind Factor
Multiply nonnegative observedDepth by positive correctionFactor and add nonnegative wettingLoss and evaporationLoss.