Snowpack Liquid Water Retention Share Tool

Description

Multiply nonnegative poreVolume by retentionFraction in [0, 1] for capacity.

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 poreVolume by retentionFraction in [0, 1] for capacity.

When to use this tool

Use Snowpack Liquid Water Retention Share when you need one supplied snow-storage or water-equivalent component.

How to use the tool and how it works

Enter poreVolume, liquidVolume, retentionFraction, meltInputVolume. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read capacity, retainedVolume, drainageVolume. Use the output convention below.

Multiply nonnegative poreVolume by retentionFraction in [0, 1] for capacity. Retain the smaller of capacity and liquidVolume+meltInputVolume and report their positive excess as drainageVolume.^[1]

Input field	Meaning and units	Accepted input
poreVolume	Pore Volume	Required. Finite number; minimum 0.
liquidVolume	Liquid Volume	Required. Finite number; minimum 0.
retentionFraction	Retention Fraction	Required. Finite number; minimum 0; maximum 1.
meltInputVolume	Melt Input Volume	Required. Finite number; minimum 0.

Output field	Interpretation	Returned shape
capacity	Capacity	Required. Finite number.
retainedVolume	Retained Volume	Required. Finite number.
drainageVolume	Drainage Volume	Required. Finite number.

json

{
  "input": {
    "poreVolume": 100,
    "liquidVolume": 10,
    "retentionFraction": 0.2,
    "meltInputVolume": 15
  },
  "output": {
    "capacity": 20,
    "retainedVolume": 20,
    "drainageVolume": 5
  }
}

Limitations and assumptions

Volumes share units; this is a supplied storage cap without percolation, refreezing, layer structure, or drainage-rate simulation.
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/snowpack-liquid-water-retention-share — 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.