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Your View | Scaling public perception of flood risk

cumbria floods

This week’s hot topics include how to mitigate flooding, continued debate over the need for A-level physics, solutions to the profile problem, and more thoughts on Heathrow capacity

 

cumbria floods

cumbria floods

Flooding: Event rating gives false sense of security

Have we not yet learnt from earlier mistakes? The Environment Agency continues to relate the magnitude of flood events to return periods. It is inevitable when the public is told it is protected to a 1 in 100 year standard they vent extreme anger when they are flooded more than once in their lifetime. It would be better to quote the chance of a flood occurring in any one year being 1%; this measure of flood magnitude would remove the widespread misunderstanding applied to repeat events.

Quite some years ago I proposed to the then Ministry of Agriculture Fisheries & Food (MAFF) a new approach when discussing flood severity within the public domain. This was to establish a simple numeric system as applied to other natural events such as those generated by high winds/hurricanes and earthquakes. The public does not challenge if it is a Force 10 wind which removes some roof tiles, or if earthquake damage occurs with a MMS reading in excess of six. The approach would numerically register the severity of the flood event with 10 and above confirming a major incident, which would be readily understood by the public without the misconception of being OK for the next 100 years once the property had dried out.

The merit of such an approach was not dismissed by MAFF but its dissolution ensured the matter was not pursued.

David Noble OBE (F Retd), former chief executive Association of Drainage Authorities david.noble123@btinternet.com

Decades of investment in research and development of hydrology, river engineering and catchment modelling, not to mention a major report from the Office of Science Technology on Future Flooding (2004), have led to this. Economic benefit-cost criteria, technically naïve managements and parsimonious governments have conspired to ignore the reality of the risks. No amount of walking in flood water wearing wellingtons and expressions of concern is going to make any difference. 

The Institution’s membership has the competence and experience to evaluate what went wrong and advise the government on what is needed. 

It could start by dusting off the 2001 Presidential Commission report on Learning to live with rivers and waving it under ministerial noses, offering to engage in knowledge-based dialogue.

Mike Thorn mfcthorn@supanet.com

I have trawled papers and listened to many radio and TV reports but never read or hear about maintenance dredging. Spending millions of pounds on capital flood defence projects does little to explain what is spent on maintenance dredging as a percentage of the capital budget. Flood defence levels have to best guess climatological future conditions and yes, a difficult job, but modelling fluvial flows that determine flood defence levels have to consider river capacities in the form of simplified cross sectional area data. It seems to me based on observation of the River Thames, very little if any maintenance dredging is done so assuming the same for other rivers how can the modellers input up-to-date data on cross sections? Let’s have more factual information on who does what and where dredging-wise and have confirmation that up to date cross sectional area data is inputted to models on a regular basis. 

Nigel Craddock, Mumbles, Swansea colombohhh@btinternet.com

We as a country are very fortunate to have a mild temperate maritime climate that provides us with rain to produce crops, enable manufacturing and good health. We are not short of water but we do have cumbersome systems of agricultural water management and a view that our landscape is to be aesthetically pleasing and sympathetic to environmental sensitivities.

At the same time, we as a country are reducing our capability to power our own energy demands with increasing amounts being imported.

Energy from water flowing in channels can be harnessed and subsequently dissipated through the construction of hydroelectric systems connecting into our National Grid. The subsequent energy dissipation reduces likely damage to bridge f oundations and enables us to harness the forces of nature for the good of mankind while limiting future flooding.

Rivers Eden and Derwent in Cumbria, Ribble and Irwell in Lancashire and Foss, Warfe and Ouse in Yorkshire are all ripe for hydropower generation with upstream attenuation basins to catch and limit subsequent water through-flow during periods of heavy rainfall. Another flood in a couple of years at a cost of say £2bn makes the business case for these bold engineering solutions increasingly palatable.

Jonathan Clarke (M) Blencathra House, Graham Street, Penrith CA11 9LE

As educated professionals, we are concerned not only at the direct impacts of the floods in Cumbria but also at the reasons for this flooding happening with increasingly regularity. Ministers acknowledge that human activities, and excessive CO2 emissions, are a primary cause. 

But as professionals with mortgages to pay, and families to support, most of us find ourselves compelled to work on projects such as the proposed expansion of Heathrow, likely to increase global CO2 emissions. High Speed 2 (HS2) is another case in point. By its own admission, it will have a broadly carbon-neutral impact over a 60 year period, in flagrant disregard of the overarching requirement of the 2008 Climate Change Act, for an 80% cut in CO2 by 2050.

If allocated budgets are anything to go by, six times more engineers will be working on Heathrow expansion (circa £15bn) than on flood defences (£2.3bn) allocated over six years).  And far more will be working on HS2.

The problem lies not with international aviation or high speed rail, but with fellow professionals charged with developing and implementing transport policy. There is no apparent concept of how airports or railways can be designed as systems to optimise economic and environmental performance.

We’ve repeatedly told the Department for Transport and HS2 Ltd that HS2’s carbon-neutral performance is unacceptable and capable of huge improvement if it were to be designed as an integrated network rather than as a stand-alone high speed line. 

It’s time for civil engineers to put their ow n house in order, and work in a joined-up fashion to achieve vital emissions reductions across every sector. 

Colin Elliff, civil engineering principal, High Speed UK, colinelliff1958@hotmail.com

A-level physics – is it essential for a civil engineer?

I have read with interest the recent correspondence about A-level physics. Having taught construction materials on a civil engineering degree course for many years, I would suggest that, while it is desirable, an A-level in physics should not be an essential entry requirement for the course.  

There is no doubt that all engineers should have a sound knowledge of many areas of physics. The properties of materials such as the factors which affect their durability cannot be understood without it. However, this subject is best delivered in a course which has immediate relevance to construction. For example, the concept of diffusion may be presented as a mechanism which moves chloride ions into concrete and illustrated with some pictures of corroding reinforcement and a discussion of how the diffusion coefficient is controlled by the water/cement ratio and curing. This is likely to mean far more to students than the discussion of an abstract concept as part of an A-level course.

Given that students starting courses in civil engineering will have varying levels of knowledge of physics, it is important that the subject is explained during the course. I always included lectures on topics such as elastic, thermal, electrical and transport properties which explained the terms used. For some students this was just revision, but even for those who had seen the terms before, it explained their relevance to construction. My recently published textbook on construction materials has chapters on each of these topics.

Peter Claisse (F) emeritus professor of construction materials, Coventry University pete@claisse.info

Physics requirement narrows civils appeal

I have recently applied to do civil engineering at university and now have received four offers. The University of Sheffield and the University of Leeds have only required maths A-level and the University of Bristol has required any science as well as maths. I believe this is because most of the mechanics covered in physics is covered by the mechanics modules in maths in greater depth and universities are already understanding the need to attract people like myself to civil engineering.

Iain Millington 09.iain.millington@lawrencesheriffschool.com

Trick question

I was amused to see that one of your readers (David Redford) is still proposing sifting out graduate job applicants by asking them a trick question requiring a mental sorting out of forces and masses (elephants, apples, trucks and kN).   Surely by now we have learnt that knowing where to look things up is far more important than memorising stuff? Each of his interviewees would have had in their pocket a little machine which, if they had any doubt at all about the relationship between masses and forces, would have confirmed the right answer in seconds. That one in three got the answer wrong proved absolutely nothing about their engineering potential. 

Michael Rowan (M) michaeljrowan@hotmail.com

Bring back the plaque

I have interviewed many undergraduates and when asked the question, “why did you choose engineering as a career?” the most common, although cliché, answer is “I want to say I have built/designed something which contributes to society and leaves a legacy”. I probably said the same, and I’m sure it’s true for most readers. To encourage more students into the industry I believe a simple but effective solution would be to bring back the plaque. Most notably seen on Victorian structures, the plaque offered the reader information on its construction and provided the name of the engineer who designed it. I can imagine the younger generation will be enthused at the prospect, as that truly is leaving a legacy.

Owen Wonorg  owenwonorg@gmail.com

Second to God

For as long as I’ve been associated with civil engineering – I started my degree course in 1965 – the Institution of Civil Engineers has attempted to raise the profile with, as far as I’m  aware, little success, so it was pleasing to read in the Sunday Telegraph that Prince Philip believes engineers to be second only to God, and that they hold the key to the future, as reported on the “Today”  programme. He is quoted as saying that “engineers could play a key role in solving problems caused by population growth”, and that ultimately it’s going to be engineers who decide how to keep the balance between the human world and the natural.

It’s good to hear that such an eminent man can present the voice of reason in these time of shrill and partisan rhetoric, so we should be grateful for his support, and hope that our profile has been raised.

Alan Mordey Leamington Spa agmordey12@btinternet.com

Turkey and Japan beat us hands down

At last a sensible decision to delay a decision on the hair-brained proposal for a third runway at Heathrow, one which will hopefully lead to its demise. Heathrow always was a lousy airport and piecemeal patch-ups and additions won’t improve it. They never do.

I fully agree with David Gem and many others that what is needed is a totally new hub airport, preferably with four runways (New Civil Engineer 19 November 2015).

What is the UK coming to? Working at geological pace it still gets everything wrong.  

Turkey is working on a new Istanbul Airport, the biggest in the world, which will probably be finished before the Heathrow scheme could even start.

Japan has had high speed rail for over 50 years and now has over 2,000km operating. By the time High Speed 2 opens, Japan will be close to a new line operating at almost twice the speed.

Tokyo alone has seven underground and several overground equivalents of Crossrail connected to an amazing rail/subway network which works like clockwork. Many other Japanese cities have similar through lines extending well beyond the city limits.

Dave Corby (F) davecorbyhk@gmail.com

 Heathrow pollution question

 Your article “Heathrow ploughs on despite six month runway decision delay”, talks of “ambitious solutions” to environmental problems (New Civil Engineer 17-24 December 2015). When air pollution problems are raised, Heathrow airport always talks about limiting surface transport and already has a low emissions zone in operation. However, the elephant in the room is the jumbo jet and the pollution caused by burning enough fuel to keep something of this size and weight in the sky. Adding up to 50% more flights without breaching European air quality limits is not just a challenge, it is impossible.

Richard Bloore (M) 89 Haliburton Road, St. Margarets, Twickenham, TW1 1PD

 Pool south east ariports

There is an obvious answer to the Heathrow/Gatwick expansion debate. Link Northolt, Heathrow and Gatwick with a high speed maglev railway system and operate them as a single airport. Northolt provides an already existing third runway for Heathrow and allows a second runway to be built at Gatwick. The combination will provide five runways for south west London.

The maglev railway would be a combination of elevated guideway and tunnel depending on noise limitations. The Crossrail team would relish some new tunnelling work.

Northolt Airport is but 10km north of Heathrow and Gatwick just 50km to the south. A maximum 10 minute transfer time between the three would be perfectly feasible with the high speed link. Further extension of the maglev to Stansted would provide six runways for London – two more than Charles de Gaulle and the same as Schiphol.

Richard Lucas (M) rjlucas56@hotmail.com

  • cumbria floods

    Your View | Scaling public perception of flood risk

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