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Introduction

The Code Dictionary is a user-friendly way to cross reference USGS water data codes and terms to related definitions.

Available references

  • Parameter Codes
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    Parameter codes are used to describe data collected by USGS. These codes always have five numerical digits and represent a constituent measured and the unit of measurement.

    In the USGS system, there are more than 19,000 parameter codes.

    With Code Dictionary you can:

    • match a parameter's description, such as Temperature, water, degrees Celsius, to a related numerical parameter code.
    • match a parameter code to a text description
    • view or download all parameter codes
  • Observed Properties
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    Observed properties are text descriptions used to describe discrete sample data collected by USGS. Observed properties describe a constituent measured, without measurement units.

    In the USGS system, there are more than 15,000 observed properties.

    With Code Dictionary you can:

    • match an observed property's description, such as Temperature, water, to related parameter codes
    • match a parameter code to an observed property
    • view and download all observed properties and a crosswalk between observed properties and parameter codes

Parameter Codes

Observed Properties