Gauge stations

This page contains technical information relating to hydrometric data available in Flood Modeller via River Stations menu under the Hydrology+ tab. For an overview of the River Stations functionality, please see the Gauge stations article under the Hydrology+ section of the knowledge base.

Data Sources

Flood Modeller provides access to river measurements (both river level and flow) collected at river gauges (also known as "stations") from across the United Kingdom. Flood Modeller current uses two sources of data:

• National River Flow Archive (NRFA) published by UKCEH
• Hydrology Data collected by the Environment Agency and published by DEFRA.

Additional details of these data sources are provided below.  We will continue to add data sources to Flood Modeller in future releases and would welcome suggestions of additional providers/sources which would support users.

National River Flow Archive

The National River Flow Archive (NRFA) is the UK’s focal point for river flow data and is maintained by the UK Centre for Ecology and Hydrology (UKCEH). The NRFA collates, quality controls, and archives hydrometric data from gauging station networks across the UK including the extensive networks operated by the Environment Agency (England), Natural Resources Wales, the Scottish Environment Protection Agency and for Northern Ireland, the Department for Infrastructure - Rivers. Full details of the NRFA are available on their website - National River Flow Archive.

Spatial distribution of NRFA river stations as seen in Flood ModellerFlood Modeller provides data from NRFA via the NRFA API with a focus on displaying data needed for flood hydrological analysis. Users are able to access information on river station types and quality, catchment descriptors and peak flow records for use in FEH analysis.

Environment Agency Hydrology Data

The Environment Agency (a non-departmental public body sponsored by DEFRA) is the gauging authority for England and maintains an extensive fleet of environmental monitoring stations. Flood Modeller makes use of the Hydrology Data API to provide data to users. The Hydrology API provides access to historic and recent hydrological data including river flows, river levels, groundwater levels, rainfall and water quality. At present Flood Modeller provides access to only river flow (m³/s) and river level (m) data, though we are planning to expand data types in future releases.

Environment Agency data can also be access via a dedicated website Hydrology Explorer.

Spatial distribution of Environment Agency river stations as seen in Flood Modeller.

 

The River Station interface is located under the Hydrology+ tab and described here, with additional details provided below.

Location of River Station menu within Hydrology+ ribbon

Gauging stations can be made visible on the map using the "View River Stations" menu. Users can choose to display all Environment Agency and NRFA data or apply filters buy station type (e.g. flow or level).

Example river gauge summary box

 Once a gauge is selected, a popup box will provide summary information about the gauge.  

• The top left hand corner lists data types available - Level and Flow (Environment Agency) and NRFA (UKCEH)
• If a NRFA station, the centre of the box summaries station quality, including:
  • Peak Flow - Whether or not the station is a Peak Flow station and included in the NRFA Peak Flow dataset.
  • Suitable for Pooling - Whether or not the station has been classified as suitable for use in FEH pooled analysis
  • Suitable for QMED- Whether or not the station has been classified as suitable for use in FEH QMED analysis

Detailed gauge information is then available by clicking "view full info" in the bottom left hand corner or "View Gauge Information" via the right click menu.

Site Info

The Site Info tab provides an overview of general details such as Catchment Area, Operating Period, FEH Suitability, and Flow Record Description. These data are sourced from NRFA via the API. 

The Recorded Datum is the adjustment between the river water level recorded at the gauge using a local datum and the Ordnance Survey datum at Newlyn. For river levels to be comparable to local topography (e.g. LiDAR) they should be adjusted by adding the datum value. Datums displayed in Flood Modeller are provided by the Environment Agency but should always be checked for accuracy. Datums can be overridden by the user as described below.

Observed Data 

Tab provides observed gauge data in both 15 minute and daily average scale from the Environment Agency.  Depending upon station type, both flow and water level data maybe available.  When first opened, there maybe a pause while gauge data are cached to enable rapid navigation, performance can be limited by network connection speeds.  By default, daily data are displayed to speed access and navigation.  At a pre-defined zoom level, the chart will change to 15 minute data.

The entire dataset can be displayed in the graph window, equipped with a movable ruler at the bottom. This ruler, sliding from both ends, allows you to narrow down your focus to a specific timeframe. 

A toolbar along the top of the window provides the following functionality:

From the Export Observed Data window, you can select from the options below:

Peak Flow Data

This tab displays the AMAX and POT data for NRFA Peak Flow gauges sourced from NRFA. Both annual maximum (AMAX) flows and peaks over threshold (POT) data are shown along side data classifications.

A toolbar along the top of the window provides the following functionality: