# OS Open Rivers Overview

OS Open Rivers provides a two-dimensional, topologically-structured link-and-node network of Great Britain’s watercourses. A link represents the approximate central alignment of a watercourse. Attribution indicates the flow direction and name of each watercourse.

OS Open Rivers is a generalised product which is automatically derived from Ordnance Survey large-scale data. The nominal usage scale is 1:25 000, with a recommended viewing scale range of 1:15 000 to 1:30 000.

## Key features <a href="#id-1.2-key-features" id="id-1.2-key-features"></a>

The key features of the OS Open Rivers product are as follows:

* Comprehensive coverage of Great Britain's river network.
* A topologically-structured link-and-node network.
* Water flow direction information.
* Classified links which allow you to identify the differences between tidal and inland rivers.<br>

<figure><img src="https://1897589978-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FcNpJpLP8RROUaWVQo5ea%2Fuploads%2FVpRbtuzvGYApCEDLbRrW%2F1.jpeg?alt=media" alt="Illustrative map image of OS Open Rivers and its associated attribution."><figcaption><p>Illustrative image of OS Open Rivers and its associated attribution.</p></figcaption></figure>

## Applications <a href="#id-1.3-applications" id="id-1.3-applications"></a>

OS Open Rivers supports a wide range of applications that use geographic information. The product can be used alone or in combination with other Ordnance Survey products, such as [Terrain 50](https://docs.os.uk/os-downloads/products/land-and-terrain-portfolio/os-terrain-50) or [VectorMap District](https://docs.os.uk/os-downloads/products/maps-and-imagery-portfolio/os-vectormap-district). OS Open Rivers has numerous applications, including but not limited to, the following examples:

* Relating information to the river network for both personal and business use
* Simple analytical queries (for example, the overall lengths of larger rivers in Great Britain)
* Simple planning around main watercourses using the detailed connectivity and flow (from source to mouth) information
* Regional-level environmental impact assessments (for example, an indication of what towns have rivers passing through them)
* Backdrop mapping

It is important to note that detailed analysis is not supported in OS Open Rivers; this requires the additional detail and complexity available in data from the [OS National Geographic Database (OS NGD) Water Theme](https://docs.os.uk/osngd/data-structure/water).