Arizona Real-time Water Quality


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Arizona Real-time Water Quality Regression Models

Many USGS stations on this website report not only continuous water-quality data that are directly measured in the stream such as temperature, specific conductance, and turbidity, but also continuous computed data such as total nitrogen and suspended-sediment concentration. The latter are computed using empirically derived site-specific regression models, which are created using established methods. The regression models have undergone a complete peer-review process, and are published and available on the web through this web page and selected interpretive reports.

A complete history of all Arizona regression models is available as a Microsoft Excel spreadsheet. It lists current models, as well as historic models that became outdated, or expressed computations in terms of non-continuous variables. Except for this spreadsheet, only the most current (active) models are shown on this website.

Current Regression Models

Screen capture highlighting the Model Info tab under the View Data area Current regression models used to compute continuous Arizona water-quality data can be viewed four ways:

  1. Sorted by publication source.
  2. As a summary Microsoft Excel spreadsheet.
  3. When exploring a computed constituent (under View Data), click Model Info to see the model used to computed those data (see figure).
  4. The original published sources of models; links are available throughout this website, including the next section of this page.

Published Sources for Current Arizona Regression Models