Flood Frequency Analysis using the FEH Statistical Method

Flooding and flood risk management is of major importance following high profile and devastating floods in recent years. This has increased the requirement for flood risk assessments and increased the scrutiny on those who manage and design bridges and culverts including local authority engineering departments. The Flood Estimation Handbook (FEH) methods provide the standard methodology for flood design but can be time consuming to implement without the associated software.

This 1 day course focuses on the FEH statistical method and the use of WINFAP-FEH 3 software to derive a flood peak of a given rarity for any gauged or un-gauged river in the UK. This offers a key starting point for any flood design work. Delegates will learn how to use the software effectively to produce flood frequency curves and gain an insight into the different flood estimation methods available, their strengths and limitations and applicability in different situations.

Our training provider is responsible for developing the WINFAP-FEH software and offers nationally-recognised expertise in the development and application of the FEH flood frequency analysis tools.

This course will enable delegates to:

Distinguish between the different FEH methods for flood estimation

Determine which FEH method is most appropriate in different situations

Understand the science behind the FEH Statistical method of flood estimation

Derive QMED (the index flood) from analysis of gauged data and adjust as required using donor data or to incorporate urban influences.

Construct a flood frequency curve using single site gauged flow data

Use the FEH CD-ROM 3 data resource to extract catchment descriptors at any chosen site

Select a pooling group of catchments with similar hydrological characteristics to the chosen un-gauged site

Review and adapt pooling groups

Construct a flood frequency curve at an un-gauged site, making adjustments for the degree of urbanisation as appropriate

Understand the limitations and strengths of the FEH Statistical method and interpret results correctly

This course will enable delegates to apply the FEH Statistical method using WINFAP-FEH 3 software to determine the flood peak of a given rarity for any chosen site in the UK. You will know how to analyse gauged flood data and how to pool data from catchments with similar catchment characteristics to derive flood flow statistics for any un-gauged site. By understanding the science behind the software you will be able to use it more effectively and interpret the results more fully, appreciating the strengths and limitations of the method. You will also have a better understanding of which FEH method is most appropriate in different situations.

Introduction

Outline of the different FEH method

Introduction to flood frequency estimation

Estimating QMED

What is QMED

For a gauge subject site

For an un-gauge subject site

Adjusting QMED using donor data

Adjustment of QMED for urbanisation

Exercise 1 – FEH CD-ROM 3 – estimation QMed

Which analysis method to use

Single site analysis

Growth curve estimation

Demonstration

Flood growth curve

Flood frequency curve

Exercise 2 – deriving a flood frequency curve using gauged data

Pooled analysis

Why use pooled analysis

Selecting pooling group member

Reviewing and adapting pooling group

Flood growth curve constuction

Adjusting for urbanisation

Demonstration

Exercise 3 – driving a flood frequency curve using pooled analysis

Questions and discussion of results

This course uses an interactive combination of presentations, practical hands-on exercises and discussion. It is presented in 4 sessions including 3 supervised practical exercises addressing key aspects of the course. The presentations are supported by comprehensive course notes and worked examples to provide a valuable reference source. With a maximum of 12 delegates per course we aim to make our training as informal as possible with plenty of time for questions and discussion.

“course was good - feel more confident now"

“happy with course – help was given when requested and tutor was happy to go through exercises and explain processes”

“the summary of background principles to the software and understanding of software limitations and suitability of use of data was rated especially good".

“explanation of single site analysis and enhanced single site analysis was very useful”

This course is suitable for both new users of FEH software and existing users who would like to consolidate their knowledge and learn more of the latest scientific advances and practical applications of WINFAP-FEH 3 software. The course will be of particular interest to engineers and modellers from consultancies involved in flood risk management, highway and urban drainage designers and development control and consenting officers. The course is also suitable for beginners who have a basic understanding of hydrology in the UK and are familiar with flood risk terminology and general concepts.

There are no pre-course requirements, although non specialists may prefer to first gain the basics of hydrology through our Introduction to Hydrology course. Course notes will be provided on the day and no pre reading is required. The trainer is always happy to advise delegates who may have specific questions from working in this area.

Laptops will be required