Engineering and the Environment

CENV6123 Coastal Flood Defence

Module Overview

This Module will introduce you to the range of skills needed in planning, managing and designing coastal defences. These skills vary from "hard" engineering to the "softer" issues of managed retreat and environmental impacts of sea level change. This module will describe current thinking and techniques used in maintaining and managing our coastline, examining the approaches used in the UK and elsewhere. The course will comprise a combination of lectures design studies, computer modelling exercises and if time and weather permit, some field visits.

Module Details

Title: Coastal Flood Defence
Code: CENV6123
Year: 4
Semester: 2

CATS points: 15 ECTS points: 7.5
Level: Postgraduate
Co-ordinator(s): Dr Derek Clarke

Pre-requisites and / or co-requisites

1 . Students taking this module MUST have taken CENV 6084 "Maritime and Coastal Engineering and Energy". 2. Students undertaking this module also need to understand Hydraulics equivalent to Part2 Civil Engineering CENV 2008 (ie open channel flow up to and including critical depth, water surface profile evaluation, knowledge of spreadsheet software to solve expressions such as Manning’s equation.)

Programmes in which this module is compulsory

ProgrammeUCAS CodeProgramme length

Aims and objectives

This Module will introduce you to the range of skills needed in planning, managing and designing coastal defences. These skills vary from "hard" engineering to the "softer" issues of managed retreat and environmental impacts of sea level change. This module will describe current thinking and techniques used in maintaining and managing our coastline, examining the approaches used in the UK and elsewhere. The course will comprise a combination of lectures design studies, computer modelling exercises and if time and weather permit, some field visits.

Syllabus

INTRODUCTION TO COASTAL FLOODING
Overview of coastal issues. Suddenness, damage caused by saltwater and river water. Examples/case studies. Current “state of the art” and “issues” in the UK. Existence of flood risk, numbers likely to be affected. Types of flooding. Environmental impacts e.g. salt intrusion into estuaries, likely impact on sensitive areas. Planning approaches used in flood defence . Foresight implications / Making Space for water/Coastal squeeze – Shoreline Management Plans. Risk Assessment for Strategic Planning (RASP). Role of the Environment Agency, DEFRA. Economic and Financial Analysis of flood damage.

HYDRAULICS AND MODELLING
Frequency analysis of extreme tidal and river flood events. Impact of sea level rise on flood frequency, tidal locking, increased winter river runoff. River outlets into the sea. Description of structures such as gates, culverts, weirs. Control points and critical depth. Gradually varied flow and flow profiles, non-steady flow, tides and hydrographs. Design Exercise Task 1 : Modelling water levels in rivers and estuaries to investigate the impact of sea level rise and river floods at vulnerable sites. Identification of required elevation of flood defences using HEC RAS computer software.

FLOOD DEFENCES
Flood protections structures (2 hrs) a) Earth structures b) Wave recurves. Tsunamis and Tsunami Engineering (4 hrs). Numerical and Physical models in coastal engineering design (2 hrs). Design Exercise Task 2 : choice of appropriate sea defences.

DESIGN EXERCISE
A town on the south coast of England with a known flood defence problem will be used as a case study. You will review existing flooding problems where a combination of tidal and river flood conditions exist as a series of coursework tasks. You will carry out modelling and design of existing and new flood defences and gated outlet structures, investigate existing and future flood risk and select new flood defences.
The case study will include :-
1. Review of historic flood damage.
2. Understanding the existing tidal gate system, measurement of tidal levels, river flows.
3. Simulating behaviour of outlet gates with existing tides.
4. Statistical analysis of extreme tide levels, estimation of flood hydrographs
5. Use of HEC RAS to simulate non steady flow behaviour of existing gates.
6. Calculation of extreme tide and pond levels and comparison with existing defences
7. Modelling the effect of sea level rise.
8. Estimation of the effect of sea level rise on flood economic impact.
9. Design of sea walls to protect against tidal flooding. Levels, Wave actions.

FIELD VISITS and GUEST LECTURES
Weather and time permitting, various half day visits will be made to local and regional sites to illustrate problems and solutions.
Engineers, planners and managers may give occasional guest lectures explaining current thinking and methodology in Coastal Engineering.

Learning and teaching

Study time allocation

Contact hours: 46
Private study hours: 104
Total study time: 150 hours

Teaching and learning methods

The module consists of a series of

  • formal lectures,
  • coursework
  • lectures from visiting professionals.
  • field visits - may include visits to Lymington, Selsey, Hayling Island, Thames Gateway.

Resources and reading list

You will be given handouts during the lectures. You do not have to buy a specific book, but you will learn much more if you obtain one of the books from the recommended book list, several of which are available in the Library. An e-book on Design in the Fluvial Environment will be made available on Blackboard.

Assessment

Assessment methods

Assessment Method Number % contribution to final mark Final assessment (x)
Design Exercise 1 HEC RAS modelling (DC) 1 20  
Examination 120 minutes 1 70 x
Design Exercise 2 Flood Defences (GM) 1 10  
Feedback Method Examination : generic feedback to all students via Blackboard. Individual exam scripts will be annotated.
Coursework : The Coursework task will be annotated and an overview of the merit of the work will be provided on the front cover
   
 Referral Method  Number % contribution to final mark  
Examination 120 minutes  1  100  x
Method of repeat year Repeat year externally Repeat year internally