Development of interim national guidance on non-stationary fluvial flood frequency estimation

New tools and techniques to help us detect and take account of non-stationarity in flood frequency estimation for flood scheme appraisal.

Documents

Development of interim national guidance on non-stationary fluvial flood frequency estimation - summary (307KB) PDF

Development of interim national guidance on non-stationary fluvial flood frequency estimation - technical report (10.9MB) PDF

Development of interim national guidance on non-stationary fluvial flood frequency estimation - practitioner guidance (1.21MB) PDF

Development of interim national guidance on non-stationary fluvial flood frequency estimation - package user guide (1.9MB) PDF

Rapid evidence assessment of non-stationarity in sources of UK flooding - summary (266KB) PDF

Rapid evidence assessment of non-stationarity in sources of UK flooding - technical report (4.8MB) PDF

Recommendations for future research and practice on non-stationarity in UK flooding - summary (214KB) PDF

Recommendations for future research and practice on non-stationarity in UK flooding - technical report (1.4MB) PDF

R package files

The zip files contain results on change point tests, multi-temporal trend testing, split sample tests and non-stationary flood frequency analysis.

Non stationarity R package (5.9MB) ZIP

Digital outputs 1 Results for change point tests, multi-temporal trend testing, split sample tests and shapefile of results for gauging stations 21032 to 77001

Digital outputs 2 Results of non-stationary flood frequency analysis using time as a covariate for gauging stations 22001 to 76015

Digital outputs 3 Results of non-stationary flood frequency analysis using physical covariates for gauging stations 1001 to 43005

Digital outputs 4 Results of non-stationary flood frequency analysis using physical covariates for gauging stations 43006 to 108001

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Details

This project has developed new tools and techniques to help us detect and take account of non-stationarity in flood frequency estimation for flood scheme appraisal.

You should apply this guidance:

  • in the appraisal of all projects. After 1 July 2021 you should submit a short form business case or outline business case to the Environment Agency for assurance and approval. A project that is submitted before then could also be assessed against this guidance to check that it would not lead to different decisions (provided this would not unduly slow completion or significantly add to the cost)

  • to your FCERM strategy if you have not already submitted it to the Environment Agency for assurance and approval. We would not usually expect this advice to be applied for existing approved plans and strategies until the next review, unless specific investment projects within them are planned before this. If this is the case however, new project appraisals should adopt the new guidance

You should use this guidance to understand how and when non-stationarity should be included in the appraisal of FCERM projects schemes and strategies. This guidance should be used with the Flood and Coastal Erosion Risk Management full appraisal guidance.

Updates to this page

Published 26 February 2021
Last updated 3 March 2021 + show all updates
  1. The documents list has been updated to include the R package and digital outputs from the project.

  2. First published.