QUAL2K JSON Schema: Import/Export Data Format Reference

The QUAL2K Web Wizard uses JSON as its native data format for saving and loading project configurations. This page documents the complete schema with annotated examples. For a description of each field's meaning and units, see the Wizard Fields Reference.

Figure 1: QUAL2K JSON schema top-level structure

Top-Level JSON Schema Structure

jsonRoot schema structure

{
  "project": { ... },
  "reaches": { "items": [ ... ] },
  "headwater": { ... },
  "pointSources": { "items": [ ... ] },
  "diffuseSources": { "items": [ ... ] },
  "kinetics": { ... },
  "lightHeat": { ... },
  "metData": { ... },
  "observedData": { ... }
}

Section: project

jsonProject configuration

{
  "project": {
    "riverName": "Rio Paraluz",
    "simDate": "2026-02-24",
    "timezone": -5,
    "calcStep": 11.25,
    "integration": "Euler",
    "simType": "Steady"
  }
}

Section: reaches

jsonReach definition array

{
  "reaches": {
    "items": [
      {
        "name": "PR1",
        "downstreamDist": 2.64,
        "upstreamElev": 45.0,
        "downstreamElev": 42.0,
        "manningN": 0.035,
        "bottomWidth": 3.0,
        "sideSlope1": 2.0,
        "sideSlope2": 2.0
      },
      {
        "name": "VPR1",
        "downstreamDist": 3.87,
        "upstreamElev": 42.0,
        "downstreamElev": 40.5,
        "manningN": 0.035,
        "bottomWidth": 3.5,
        "sideSlope1": 2.0,
        "sideSlope2": 2.0
      }
    ]
  }
}

Section: headwater

jsonHeadwater boundary conditions

{
  "headwater": {
    "flow": 0.06,
    "temperature": 22.0,
    "do": 7.5,
    "cbodFast": 4.0,
    "cbodSlow": 2.0,
    "orgN": 200,
    "nh4": 150,
    "no3": 600,
    "orgP": 50,
    "inorgP": 100,
    "iss": 10,
    "cond": 350,
    "pathogens": 5000,
    "alk": 100
  }
}

Section: pointSources

jsonPoint sources array

{
  "pointSources": {
    "items": [
      {
        "name": "WWTP Effluent",
        "location": 3.5,
        "flow": 0.02,
        "abstraction": 0,
        "temperature": 25.0,
        "do": 2.0,
        "cbodFast": 15.0,
        "nh4": 8000,
        "no3": 2000,
        "pathogens": 50000
      }
    ]
  }
}

Section: kinetics

jsonKinetic rate constants

{
  "kinetics": {
    "kdc": 0.20,
    "kdcs": 0.01,
    "khc": 0.02,
    "kn": 0.20,
    "ki": 0.00,
    "khn": 0.02,
    "khp": 0.01,
    "kb": 1.00,
    "vss": 0.00,
    "ron": 4.57,
    "SOD": 0.00
  }
}

JSON Schema Data Types

Field Type	JSON Type	Example	Notes
Names	string	"PR1"	Free text identifier
Distances	number	2.64	Kilometers, always positive
Elevations	number	45.0	Meters above sea level
Flows	number	0.06	Cubic meters per second (m³/s)
Concentrations	number	150	mg/L or μg/L as indicated
Rates	number	0.20	Per day (day⁻¹)
Arrays	array of objects	[{...}, {...}]	Multiple reaches, sources
Dates	string	"2026-02-24"	ISO 8601 format