Water Quality

Description

Water Quality data model is intended to represent water quality parameters at a certain water mass (river, lake, sea, etc.) section

Data Model

A JSON Schema corresponding to this data model can be found here.

  • id : Unique identifier.

  • type : Entity type. It must be equal to WaterQualityObserved.

  • dateModified : Last update timestamp of this entity.

    • Attribute type: DateTime
    • Read-Only. Automatically generated.
  • dateCreated : Entity's creation timestamp.

    • Attribute type: DateTime
    • Read-Only. Automatically generated.
  • location : Location where measurements have been taken, represented by a GeoJSON Point.

  • address: Civic address where the Water Quality measurement is taken.
  • refPointOfInterest : A reference to a point of interest associated to this observation.

    • Attribute type: Reference to an entity of type PointOfInterest
    • Optional
  • dateObserved : The date and time of this observation in ISO8601 UTCformat. It can be represented by an specific time instant or by an ISO8601 interval.

    • Attribute type: DateTime or an ISO8601 interval represented as Text.
    • Mandatory
  • source : A sequence of characters giving the source of the entity data.
    • Attribute type: Text or URL
    • Optional

Common water quality parameters

  • temperature : Temperature.
    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: Celsius Degrees.
    • Optional
  • conductivity : Electrical Conductivity.
    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: Siemens per meter (S/m).
    • Optional
  • conductance : Specific Conductance.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: Siemens per meter at 25 ÂșC (S/m).
    • Optional
  • tss : Total suspended solids.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: milligrams per liter (mg/L).
    • Optional
  • tds : Total dissolved solids.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: milligrams per liter (mg/L).
    • Optional
  • turbidity : Amount of light scattered by particles in the water column.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: Formazin Turbidity Unit (FTU).
    • Optional
  • salinity : Amount of salts dissolved in water.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: Parts per thousand (ppt).
    • Optional
  • pH : Acidity or basicity of an aqueous solution.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: Negative of the logarithm to base 10 of the activity of the hydrogen ion.
    • Optional
  • orp : Oxidation-Reduction potential.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: millivolts (mV).
    • Optional

Concentrations of chemical agents

This data model is flexible enough to accommodate different chemical agents present in water and which can be measured. Applications MUST declare the list of chemical agents which concentration is being measured. The measurand attribute must be used for such purpose.

  • measurand : An array of strings containing details (see format below) about extra measurands provided by this observation. + Attribute type: List of Text. + Allowed values: Each element of the array must be a string with the following format (comma separated list of values): <measurand>, <observedValue>, <unitcode>, <description>, where: + measurand : corresponds to the chemical formula (or mnemonic) of the measurand, ex. CO. + observedValue : corresponds to the value for the measurand as a number. + unitCode : The unit code (text) of measurement given using the UN/CEFACT Common Code (max. 3 characters). For instance, M1 represents milligrams per liter. + description : short description of the measurand. + Examples: "NO3,0.01, M1, Nitrates" + Optional

Below there is a list of typical chemical agents measured when analysing water quality. If such chemical agents are measured data providers MUST use the property names expressed by the following list. Nonetheless, the measurand attribute MUST be used to declare them, so that applications can discover what extra measurands are available as part of an observation.

  • O2 : Level of free, non-compound oxygen present.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: milligrams per liter (mg/L).
    • Optional
  • Chla : Concentration of chlorophyll A.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: micrograms per liter.
    • Optional
  • PE : Concentration of pigment phycoerythrin which can be measured to estimate cyanobacteria concentrations specifically.
    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: micrograms per liter.
    • Optional
  • PC : Concentration of pigment phycocyanin which can be measured to estimate cyanobacteria concentrations specifically.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: micrograms per liter.
    • Optional
  • NH4 : Concentration of ammonium.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: milligrams per liter (mg/L).
    • Optional
  • NH3 : Concentration of ammonia.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: milligrams per liter (mg/L).
    • Optional
  • Cl- : Concentration of chlorides.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: milligrams per liter (mg/L).
    • Optional
  • NO3 : Concentration of nitrates.

    • Attribute type: Number
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Default unit: milligrams per liter (mg/L).
    • Optional

Note: JSON Schemas only capture the NGSI simplified representation, this means that to test the JSON schema examples with a FIWARE NGSI version 2 API implementation, you need to use the keyValues mode (options=keyValues).

Examples

key-value pairs Example

{
    "id": "waterqualityobserved:Sevilla:D1",
    "type": "WaterQualityObserved",
    "dateObserved": "2017-01-31T06:45:00Z",
    "measurand": [
        "NO3, 0.01, M1, Concentration of Nitrates"
    ],
    "location": {
        "type": "Point",
        "coordinates": [  -5.993307, 37.362882 ]
    },
    "temperature" : 24.4,
    "conductivity": 0.005,
    "pH": 7.4,
    "NO3": 0.01,
}

Test it with real services

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