Posted by: waterworks | May 5, 2008

29. The UK Risk List 2008

Academics at University College London (UCL) have produced a report for UK fund manager Hermes alerting property investors to the unpalatable truth that settlements in southern England are more likely to become flooded than their northern cousins in years to come.  Property investors who failed to attend GCSE geography lessons at school, take heed.   The net effect of projected global rises in sea level acting in conjunction with long-term land movements will continue to be: a sinking south and a rising north.  Given that house prices across the UK are now starting to tumble – perhaps towards freefall – long term risk over insurability in the south is hardly cheering news for owners of low-relief housing stock in this region, especially along the Thames floodplain (and a newly-televised fictional account of the flooding of London – imaginatively entitled Flood! – has recently materialised just in time just to rub salt in the wound). 

The UCL report highlights the unforeseen problems facing city centres in the south, where it euphemistically flags up “a lack of coping strategies” (roughly translates to a phrase that includes key phrases “shit creek” and “paddle”).   The report breaks down the main risks as: increased temperatures and heat waves affecting the internal comfort levels of buildings and storage; extreme rainfall and flooding, leading to property damage; drought affecting water supplies; reduced soil moisture leading to damaging ground movement; and increased wind speed, with subsequent risk of structural damage.  The report found that extreme rainfall and associated local flooding would be the greatest climatic threat to commercial property.  Without any further ado, the metropolitan flooding risk list of 2008 (rated by top UCL scientists according to “vulnerability of cities to climate change”) is as follows:

  • Southampton #1
  • Bristol #2 
  • Cardiff #3 =
  • Thames Gateway #3 =
  • Cambridge #4 =
  • London #4 =
  • Birmingham #5
  • Leeds #6
  • Liverpool #7 =
  • Manchester #7 = 
  • Newcastle #7 =
  • Edinburgh #8
  • Belfast #9
  • Glasgow #10


The full report can be read here.

Posted by: waterworks | April 16, 2008

28. Weird water stories (case of the rubber ducks)

Sixteen years after they first leapt overboard into the Pacific Ocean, a flotilla of small plastic ducks (along with some beavers and turtles) is heading for Britain’s beaches.  29,000 plastic bath toys were released when their container was washed off a Chinese cargo ship in 1992, subsequently providing an unparalled data set for researchers with an interest in ocean circulation.  Curtis Ebbesmeyer (the severed feet consultant) is one such scientist who has been tracking the ducks.  Their movement has been inputted by Ebbesmeyer into a computer model called OSCUR (Ocean Surface Current Simulator).  Developed by James Ingraham, OSCUR uses air pressure measurements as a means of calculating the direction and speed of wind across the oceans – and consequent surface currents.



After some ducks first washed up in 1993 near Sitka, Alaska – a full ten months after their great escape, – the scientists used OSCUR to correctly predict that the remainder would follow the Sub-polar and 6,800 mile-long Subtropical Gyres of the North Pacific Ocean.  The Gyre currents did indeed induce a mass westward flocking of tiny plastic water fowl to Japan.  From there, they promptly doubled-back to Alaska, thereby completing an approximately oval circuit (one that roughly marks the extent of the filthy Pacific Garbage Patch).  Upon their return to Alaska (by now it was the end of the 1990s), many of the ducks haplessly drifted northwards, decelerating into the Bering Strait to become trapped in slow-moving pack ice.  Ebbesmeyer forecast the toys patiently sitting on their frozen tails for five or six loooooooong years before next reaching the North Atlantic, where warmer waters would finally thaw the ice and bring liberation; further adventures might then reasonably be expected to take place in Canada, Greenland and New England – ending with the Gulf Stream ushering a warm north-westerly paddle towards the British Isles.  All of this has now come to pass, exactly as Ebbesmeyer said.  Expect the ducks to turn up on British beaches any day now – by which point, the hardly little critters will have travelled 17,000 miles.




This graphic shows the Pacific orbital path taken by the ducks.

Posted by: waterworks | April 10, 2008

27. Armadas, monks and meanders

Following on from Thread 26, it seems possible that those meandering river channels so archetypically associated with lowland England may owe something to the Spanish Armada.  Until the Middle Ages, braided channels were far more common in western Europe than they are today (‘braided’ denotes the presence of a cluster of gravely islands  aits or eyots in ye olde English – around which channel waters diverge and convolute).  According to recent research by Robert Francis, braiding gave meandering a run for its money when deciduous woodland still covered lowland Britain.  Severed limbs of timber – parted from trees by such tortures as wind, mildew or rot – were in more plentiful supply for streams and rivers than today.  The Medieval river channel would therefore have been no stranger to the kind of large woody debris that might form a nucleus for sediment deposition and island bio-construction (corroborating his thesis, Francis can quote laboratory studies where the addition of bank-side vegetation has led to a complete change in channel flow pattern from braided to meandering). 

During the later Middle Ages, oak forest was  widely uprooted to provide timber for Tudor warships, thereby drastically altering river channel form and process.  In Landscape and Memory (1996), Simon Schama argued that from Tudor times onwards the patrician role of the British monarchy as ‘guardian of the greenwood’ played second fiddle to a militaristic foreign policy.  Material demand for felled timber and farm land also grew in line with the rapidly expanding population, while dissolution of the monasteries freed forested land to entrepreneurial bidding – inevitably accelerating rates of deforestation.  With trees left thin on the ground as a result of maritime ambition and monastic decline, the potential for river braiding most likely diminished somewhat – and well-defined meanders became a relatively more common river landform in some lowland environments.    

Posted by: waterworks | March 29, 2008

26. River restorers ♥ meanders

The phrase ‘river restoration’ describes an attempt to reverse-engineer a modified watercourse back to its imagined ‘natural’ state.  ‘Imagined’ is very much the operative word here, as photographic records rarely exist to provide aspiring restorers with a definitive goal.  Instead, they must apply a generic template, such as the Rosgen Classification of Natural Rivers.  This system suggests a number of channel form ‘archetypes’ that restorers can pick and choose from as they go about their intuitive work – a kind of fluviogeomorhphological salad bar. 

Now this is not necessarily always a good thing.  According to Professor Matt Kondolf (Berkeley), the Rosgen system unwittingly embraces a fetishism for European landscape design – notably a well-marked cultural preference for the meandering river form (as modelled so well by the Thames in her lower course, where she snakes from side to side in a well-defined and regal manner).  Working slavishly with Rosgen, the US restoration fraternity may be guilty of sometimes championing thoroughly inappropriate meandering restoration schemes for some American rivers.  In such cases, the restoration of a braided river channel – a branching, sinewy, badlands type of critter, all choked up on the mess of gravelly islands in its outlaw gut – could be a more appropriate management response than the (re)creation of an ersatz Thames. 

Citing the case of  Uvas Creek, California, Kondolf suggests that a lack of historical investigation – allied with a cultural leaning towards meandering on the part of the restorers – resulted in the wrong channel type becoming retro-fitted:  “A 0.9 km-reach of Uvas Creek, California, was reconstructed as a sinuous, meandering channel in November 1995.  In February 1996, this new channel washed out… Our historical geomorphological analysis showed that the reach had been braided historically, typical of streams draining the California Coast Ranges, with episodic flows and high sand and gravel transport.  After the project washed out, Uvas Creek re-established an irregular, braided sand-and-gravel channel… Our study casts doubt on several assumptions common in many stream restoration projects: … that a channel classification system is an easy, appropriate basis for channel design;  and that a new channel form can be imposed without addressing the processes that determine channel form.” 


Basically, it turns out that meanders get washed away if they’re put into the wrong places (the photographs above show the sad fate of the river restorers’ splendid new meanders after the first flood came). Read more about Rosgen here and more about Kondolf’s work here.




Posted by: waterworks | March 20, 2008

25. When plastic bags cause floods

If polar bears are now poster boys for climate change, then plastic bags are the new pallbearers for poor old planet earth.   From San Francisco to Modbury (a quaint Devon town that has sprung from nowhere to become Britain’s ban-the-bag cheerleader), the plastic bag is, all of a sudden, persona non gratis.  People it seems have woken up to the fact that any wider social commitment to reduce carbon emissions sits uneasily alongside the continued energy-intensive mass production of this instantly disposable product (a mayfly of consumer culture, the humble giveaway bag averages but 15 minutes of useful life).  Concern for sea turtles and other marine animals (who are haplessly swallowing large quantities of bags, or fragments of bags) has been another powerful driver for change.  Both sets of motivations appear genuinely altruistic – rooted as they are in worries over well-being for future generations of people and marine wildlife. 

However, there is no real substitute for having a clear, present and direct threat against current human well-being to really effect political change.  In China and Bangladesh, such a threat has arisen and the use of thin (<0.025mm thickness) plastic bags has been prohibited at the highest level.  A proliferation of small bags is blocking watercourses and sewers in these two nations, greatly exacerbating flooding, especially during the monsoon season.  As a result, Asia has quickly become a world leader in terms of outright plastic bag bans.  Unfortunately, legislation is proving both difficult to enforce and controversial.  In Bangladesh, the use of flimsy bags is still widespread, six years after a ban was first introduced.  While in China, where the ban became law at the start of 2008, bag manufacturer Suiping Huaqiang Plastic, which employs 20,000 people, has already gone into liquidation.  

More ‘battles of the bag’ can be expected in the future, especially given that some alternatives – including greater use of giveaway paper bags, linen bags and the like – are not uncontroversial themselves, given that carbon is still emitted through their manufacture.  Cynics will also worry that plastic bag bans cast far too comfortable an illusion of sustainable living.  Many families, it seems, abandon the use of disposable plastic bags the same week that they buy a big plasma screen telly (perhaps in celebration of their imagined carbon neutrality).  But only the most curmudgeonly of cynics would deny that plastic bag bans are, at least, a step in the right direction.

Posted by: waterworks | March 15, 2008

24. Weird water stories (case of the floating feet)

According to Professor Curtis Ebbesmeyer (Washington), right shoes take a different course from left shoes when lost at sea. Ebbesmeyer’s ideas have an important bearing on the case of  three severed left feet (still wearing trainers) found on beaches near Vancouver Island in recent months.  Canadian police, quite naturally, suspect foul play.  The finding of one left foot may indicate that an unfortunate yet innocent boating accident has   taken place.  Whereas an abundance of left feet appearing in so short a space of time could be suggestive of a more sinister ritualistic or criminal element at work – at least to the oceanographically-untrained eye.  

However, the oceanographically-trained eye of Ebbesmeyer detects a physical system at work here.  He believes that the left feet may simply have detached themselves from decomposing bodies in entirely unconnected boating accidents before floating away (still encased in buoyant training shoes): “Left foot wear and right foot wear often tend to wash up at different times at different places because they float differently. There are beaches that collect mostly rights and other beaches that collect mostly lefts. The winds of the currents sort out left and right foot wear.”  Meanwhile, back at Vancouver Island, the latest word from the Royal Canadian Mounted Police is that the case is still regarded as “very unusual”.  The police have recently revealed that two of the feet are size 12.  Secrecy is being maintained over the size of the third.  

Ebbesmeyer’s body of oceanographic work (he is well-regarded for his rubber duck studies) is definitely worth a read.

Posted by: waterworks | March 7, 2008

23. Why hairdressers have a low flood risk

Hair salons typically have a lower flood risk than many other types of business or homes. A fondness for stone or tiled flooring (so easy to sweep shorn locks) and waist-high electric sockets (just the ticket when repeatedly plugging and un-plugging straighteners, crimpers and driers) make hairdressers a resilient species, come the flood. Water can enter unannounced through the salon door and ebb away effortlessly later without causing too much lasting damage – assuming the flood height is insufficient to reach the raised electrics.  Admittedly, the intermingling of raw sewage with floodwater will most likely necessitate the application of a goodly amount of soap, bleach and elbow grease.  However, a hair salon might hypothetically be back on its feet and ready for business within very little time following a flood – unlike most other types of business premises, whose carpets, floor-level sockets, stocks and shelving are left thoroughly distressed and may require months of repair and replacement.  All of which results in a markedly lessened risk of losing one’s livelihood to flooding should one happen to be a hairdresser.  Although this is conditional upon one not happening to be a hairdresser living on an active flood plain who has made the category error of installing laminate wooden flooring instead of sensible tiles. 


 Check out those low-risk electrics

Posted by: waterworks | February 27, 2008

22. Are You Resilient? (2)

Flood resilience is on the rise – or at least talk of flood resilience is.  Norwich Union have a splendid new “resilient home” website that simulates the additional insurance losses that are likely to be racked up by the flooding of a non-too-resilient home.  If flood resilient measures are installed, then £23,100 (a very specific sum) and 42 repair days can be saved (presumably this is dependent upon whether Easter, Christmas and other bank holidays coincide with the wet weather).  Meanwhile, the Association of British Insurers (ABI) are concerned that of the 2 million homes at risk from coastal or inland flooding (10 % of homes in the UK), significant numbers are unhappily lacking in the resilience department. 

ABI believe that individual property owners can do much to increase the resistance and resilience of their properties to flood damage, perhaps acting in partnership with their mortgage provider, insurer, or local authority.  They offer many practical steps that homeowners can take to reduce the cost of flood repairs and speed up recovery times – such as putting one-way valves into drainage pipes to prevent sewage backing up into the house (because no-one wants that).  Finally, CIRIA have a great new report on the “flood performance” of new buildings that can be read by interested parties.  The phrase “flood performance” describes the flood resilience of buildings through the use of improved materials, methods and details.  It is not an oblique reference to the dancing of Gene Kelly. Are you resilient yet?

Look at this none-too-flood-resilient home (Source: CIRIA)

Posted by: waterworks | February 23, 2008

21. Water Miles (4) Pacific Garbage Patches

Of the 13 billion plastic liquid containers that were used in the UK alone last year, just three billion were recycled.  What became of the remaining ten billion empty bottles?  Many will have been destined for landfill.   A significant number of others undoubtedly found their way to the Pacific Ocean, carried by run-off and sewer discharge from urban areas.  The Pacific’s “Eastern Garbage Patch” is a rubbish-strewn region of its northern waters which comprises hundreds of square miles.  It was first encountered by researchers in 1999 who counted one million pieces of plastic per square mile, most of it in the form of tiny fragments (the result of attrition and other erosion processes).  Plastic is now believed to constitute 90 per cent of all rubbish floating in the oceans and the UN Environment Programme estimates that every square mile of ocean contains 46,000 pieces of floating plastic.  Looking on the bright side of life, if the fragments of old water bottles and other plastics are pale enough in colour then they could have a higher albedo than the surrounding waters.  This would result in the reflection of greater amounts of sunlight, leading to marginally less warming of the Pacific Ocean – all of which might go some small way towards tackling climate change.

Read more on plastic waste here and more on ocean circulation weirdness here.

Posted by: waterworks | February 18, 2008

20. Water Miles (3)

February 2008 has seen both Britain’s media and its politicians declaring war on the bottled water industry and the excessive distances that bottled water is travelling to reach the UK.  Stunning facts have been presented by newspapers, including the news that one in five people are apparently “too scared” to ask for tap water in restaurants.  Other choice data  are as follows: 

  • Britons drink three billion bottles of bottled water every year.  Half a billion are flown or shipped in from overseas, leaving a huge carbon footprint.
  • Transporting bottled water in the UK is estimated to produce about 33,200 tons of carbon dioxide emissions – equivalent to the annual energy use of 6,000 homes). 
  • A bottle of Waiwera water (from New Zealand) travels 18,000 km to reach the UK. 

Additional facts that may help explain why many environmentalists view the mass consumption of bottled water as normalised insanity include: 

  • Tap water is on average 500 times cheaper than bottled. 
  • An adult drinking eight glasses a day would pay just £1 a year through their tap water charges, and £500 a year if they drank a mid-range mineral water. 
  • Collectively we spend five times more on bottled water each year than it would cost to end the annual 1.8 million deaths of children from waterborne illness. 
  • It takes 162g of oil and seven litres of water (including power plant cooling water) just to manufacture a one-litre bottle, creating over 100g of greenhouse gas emissions (10 balloons full of CO2) per empty bottle. 
  • To make the 29bn plastic bottles used annually in the US, the world’s biggest consumer of bottled water, requires more than 17m barrels of oil a year, enough to fuel more than a million cars for a year. 
  • Americans throw 30m water bottles into landfill every day. 

All is not lost, however.  Government ministers acting alongside Thames Water (the UK’s biggest water provider) are reported by The Guardian newspaper as seeking “to end a long-standing culture of tap water snobbery by urging restaurants and cafes to routinely serve free tap water to their customers”.  Environmentally-conscious consumers may also now be voting with their wallets.  UK sales of the main brands of bottled water fell by 3.4 per cent last year, and 8.1 per cent for own brands.  Unfortunately, falling bottled water sales are unlikely to be helpful for the down-turning British economy, whose recent plight has become the main pre-occupation of both media and politicians (when not casting aspersions on the relatively buoyant bottled water retail sector).

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