Source: https://guthlabs.ai/docs/instruments/hydraulic-conductivity-darcy-flux/mechanism/

instrument mechanism / verified-clean

# Hydraulic Conductivity / Darcy Flux mechanism

The inspectable method record for Hydraulic Conductivity / Darcy Flux, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Model scope

The algebraic formulas are standard: q = -K·(dh/dl) and Q = q·A. Review is required because the input named only 'hydraulic gradient' without specifying signed versus magnitude semantics, coordinate direction, or output sign convention. The stated honest label should also explicitly distinguish Darcy flux from pore-water velocity. If the promised typical-K reference table is part of the product, its material categories, units, ranges, and provenance must be specified; it is not needed when K is entered directly.

No additional formula finding is recorded.

## Units and conventions

- K must use a length/time unit system consistent with the desired q and Q units, such as m/s or m/day.

- The hydraulic gradient is dimensionless and must be interpreted as the signed derivative dh/dl along the chosen coordinate direction.

- A is the cross-sectional area perpendicular to flow, in units such as m².

- q has units of length/time, and Q has units of volume/time.

- The minus sign means flow is toward decreasing hydraulic head when the coordinate direction and dh/dl sign are defined conventionally.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "K": 0.0001,
    "K_units": "m/s",
    "hydraulic_gradient": -0.02,
    "gradient_units": "dimensionless signed dh/dl",
    "area": 50,
    "area_units": "m^2"
  },
  "expected_outputs": {
    "q": 0.000002,
    "q_units": "m/s",
    "Q": 0.0001,
    "Q_units": "m^3/s"
  },
  "working": "q = -K·(dh/dl) = -(0.0001 m/s)·(-0.02) = 0.000002 m/s. Q = q·A = (0.000002 m/s)·(50 m^2) = 0.0001 m^3/s."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

Extreme finite inputs overflow the plain JavaScript arithmetic: multiplying 1e308 by 1e308 yields Infinity, so q and Q become -Infinity. The instrument should reject or flag this rather than present it as a finite physical result.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/hydraulic-conductivity-darcy-flux/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/hydraulic-conductivity-darcy-flux/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/hydraulic-conductivity-darcy-flux/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche5/tranche5-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`