FEH Catchments

Overview

FEH (Flood Estimation Handbook) catchment descriptors provide the catchment characteristics and rainfall data to support the methods outlined in the Flood Estimation Handbook to estimate river flows. Catchment descriptors were originally published in 1999 alongside FEH and have been updated and maintained by UKCEH since. There are two sources of catchment descriptors:

1. National River Flow Archive (NRFA) Peak Flow Database - FEH Catchment Descriptors are provided by UKCEH for all Peak Flow river gauges in the UK
2. FEH Web Service - A paid-for service by UKCEH which provides catchment descriptors for all ungauged river catchments in the UK with an area greater than 0.5km²

Hydrology+ supports access to catchment descriptors from both sources. This article focuses on managing data sourced from the FEH Web Service.

You can import FEH catchments into your Hydrology database and view both the details and the catchment area in Flood Modeller. From any FEH catchment, you can choose to start a Calculation point - using the catchment descriptors in ReFH2/WINFAP hydrological analysis.  

Further technical details of the FEH Catchments functionality is provided in this Technical Reference guide.

Using FEH catchment descriptors

Import your FEH catchment data once, then use it in all future hydrology+ projects.

1. Download and import FEH catchment descriptors from the Hydrology+ tab. Click Import FEH to browse to catchment data.
2. Use the View FEH catchments button to display catchments in the Map view, and the FEH Tabular View button to display the catchments in a list. 
3. Right-click a catchment from the Map or tabular view to access the option to create a Calculation Point. This is a point for you to perform your hydrological analysis. 

Importing data

FEH descriptor data can be purchased via the FEH Web Service. Details of how to register for a free account and buy data are provided on the service website. Data can be imported into the Hydrology+ database from both single or bulk downloads. 

1. Sign in to the webservice via the Download button to access your FEH Webservice account.
2. Download catchment descriptors either individually or in bulk from the webservice.
3. Import data into Flood Modeller using the Import FEH function.

Your FEH catchment data is imported to your Hydrology database. This can then be accessed in all your future hydrology+ projects.

Viewing catchments

Once imported, you can view catchments in the map using the View FEH catchments button. Click this button again to hide the catchments. FEH catchment descriptors can also be viewed in a table. Click the FEH Tabular view button to open this table.

There are 3 ways to view the descriptors for a selected catchment:

• From the tabular view, double-click the row in the table.
• From the tabular view, right-click the row and select View catchment descriptor info.
• From the Map view, right-click the catchment and select View catchment descriptor information.

FEH Example Data displayed in Flood Modeller

Full details of all options provided within FEH catchments are provided in the FEH catchments Technical Reference.

Creating Calculation points

From an FEH catchment descriptor, a Calculation point can be created. To do this, select Create calculation point from the right-click menu. This option is available from both the Map view and FEH Tabular View.

Further details of using calculation points for hydrological analysis can be found in this article on Calculation points.