Snow Water Depth Contribution Tool

Description

Multiply nonnegative snowDepth by suppliedSnowDensity/positive suppliedWaterDensity for waterDepth, then by coveredFraction in [0, 1].

Snow water equivalent expresses stored water as a depth using snow thickness and density. Layer accounting and liquid-water assumptions matter because separately included components can otherwise be counted twice.

Multiply nonnegative snowDepth by suppliedSnowDensity/positive suppliedWaterDensity for waterDepth, then by coveredFraction in [0, 1].

When to use this tool

Use Snow Water Depth Contribution when you need one supplied snow-storage or water-equivalent component.

How to use the tool and how it works

Enter snowDepth, suppliedSnowDensity, suppliedWaterDensity, coveredFraction. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read waterDepth, weightedWaterDepth. Use the output convention below.

Multiply nonnegative snowDepth by suppliedSnowDensity/positive suppliedWaterDensity for waterDepth, then by coveredFraction in [0, 1].^[1]

Input field	Meaning and units	Accepted input
snowDepth	Snow Depth	Required. Finite number; minimum 0.
suppliedSnowDensity	Supplied Snow Density	Required. Finite number; minimum 0.
suppliedWaterDensity	Supplied Water Density	Required. Finite number; strictly above 0.
coveredFraction	Covered Fraction	Required. Finite number; minimum 0; maximum 1.

Output field	Interpretation	Returned shape
waterDepth	Water Depth	Required. Finite number.
weightedWaterDepth	Weighted Water Depth	Required. Finite number.

json

{
  "input": {
    "snowDepth": 100,
    "suppliedSnowDensity": 200,
    "suppliedWaterDensity": 1000,
    "coveredFraction": 0.5
  },
  "output": {
    "waterDepth": 20,
    "weightedWaterDepth": 10
  }
}

Limitations and assumptions

Densities share units; weightedWaterDepth is an area-share contribution, not an observed catchment mean or meltwater yield.
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

Review the sampling method, density basis, layer structure, and complete snow-process model before estimating available water.

References

Calculation and input contract: hydrometeorology/snow-water-depth-contribution — tool.io

Similar or alternative tools

Snowpack Layer Water Ratio
Sum layer thicknesses and thickness times snow/water density ratio; divide equivalent depth by snow depth or return zero with defined false.
Snow Water Equivalent One Layer Term
Multiply nonnegative snowDepth by snowDensity/positive waterDensity for solidWaterEquivalent and add nonnegative liquidWaterDepth.