From the University of Southampton , word that mostly increased flooding is a reporting bias due to proximity, much like we have a reporting bias in tornado counts because there are more people to witness them than 50-100 years ago and greater urbanization.
Increase in reported flooding a result of higher exposure
A rise in the number of reported floods in the UK over the past 129 years can mainly be explained by increased exposure, resulting from urban expansion and population growth, according to new research by the University of Southampton.
In one of the most comprehensive studies of its kind, scientists have discovered that although the number of reported floods has gone up during the 20th and 21st Century, this trend disappears when the figures are adjusted to reflect population growth and increased building numbers over the same period.
Published in the journal Hydrological Sciences, the study looks at data sets from 1884 to 2013 and found an upward trend in reported flooding, with flood events appearing more frequently towards the end of the 20th century, peaking in 2012 when annual rainfall was the second highest in over 100 years.
The rise in UK flood reports over the 20th Century coincides with population growth from 38.2 million to 59.1 million and a tripling in the number of houses, from 7.7 million to 24.8 million.
“As a result there were more properties exposed to flooding and more people to report flooding,” says lead author Andrew Stevens. “A higher exposure to flooding will result in more reported flood events and larger potential damages.”
The study found significant variation between decades in both the raw and adjusted data, with the years between 1908 -1934, 1977 – 1988 and 1998 – 2013 featuring a relatively high numbers of reported floods.
The effect of increasing and improving flood defences is unclear. While upgrades to artificial defences, like the Thames Barrier, have reduced the effect of extreme sea level events, natural flood defences may have declined over the study period.
“Attributing periods of reduced flood damage simply to the effects of improved management is difficult and must be done with care,” says co-author Derek Clarke.
Professor Robert Nicholls adds “These observations should not stop concern about future flood impacts, especially in coastal areas where faster sea-level rises are expected and areas potentially exposed to higher rainfall intensities. Future flood risk may be very sensitive to changes in funding or management approaches and this has important implications for decision makers.”
The paper:
http://dx.doi.org/10.1080/02626667.2014.950581
Trends in reported flooding in the UK: 1884–2013
Andrew J. Stevens, Derek Clarke & Robert J. Nicholls
Abstract
A long term dataset of reported flooding based on reports from the UK Meteorological Office and the UK Centre for Ecology and Hydrology is described. This is possibly a unique dataset as the authors are unaware of any other 100+ year records of flood events and their consequences on a national scale. Flood events are classified by severity based upon qualitative descriptions. There is an increase in the number of reported flood events over time associated with an increased exposure to flooding as floodplain areas were developed. The data was de-trended for exposure, using population and dwelling house data. The adjusted record shows no trend in reported flooding over time, but there is significant decade to decade variability.
This study opens a new approach considering flood occurrence over a long timescale using reported information (and thus likely effects on society) rather than just considering trends in extreme hydrological conditions.
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the main problem is building housing estates on Flood Plains (the clue is in the name), and then to prevent flooding they put up flood defences.
But this merely constricts and deepens the flood, and sends it onto unprotected areas below. Then they scream that “xxxxxx has never been flooded before (in hundreds of years)”. Yeah, but xxxxxx used to be protected by flood plains upstream, that soaked up the flood, until they were built upon.
ralph.
The problem is not limited to housing that is built on flood plains.
When housing is built on flood plains, often new flood defences are put in, so as to try and protect those new homes from flooding. However, very often this new flood defence creates a problem. By not allowing a river to flood in its usual and historic flood plain, in times of high river flow, the river backs up resulting in the river flooding in areas where historically it did not use to flood.
Hence, we are today seeing flooding in new areas which in the past were not prone to flooding. And this new flooding is the direct result of new flood defences being installed in the traditional and historic flood plain of the river.
This is often under-appreciated especially by MSM which likes to sensationalise everything. It likes to run stories to the effect that the river has never flooded here before, worst flood ever etc, without explaining the reason for the new trend is flood defences being built in the usual and historic flood plain of the river.
Flooding is only a matter of efficient land management. There are no insurmountable problems. Indeed, the Netherlands establishes that.
Not to be forgotten is the EU/ green policy of actively returning drained farmland to marshland. When senior staff at the Environment Agency want to ‘stick a limpet mine on every pumping station’, it should hardly come as a suprise that the result is more flooding.
There are some other known effects in the UK. For example following replacement of the natural oak woodlands in the Welsh hills by commercial pine plantations the rain run-off characteristics changed causing frequent winter floods in the Severn valley downstream. As a result the Clywedog dam was built in the head waters as a flood control measure to retain the winter rains and release them gradually during the summer.
Admad says:
August 20, 2014 at 2:15 am –
‘Do I detect the merest faint beginnings of a sniff of a hint of a shuffle of a smidgin of movement away from catastrophism and towards more grown-up sensible logic and fact-based research? ‘
I’m afraid not: the High Priestess has spoken to the Times today (she’s not having anyone p–s on her altar!):
‘Derek Clarke, a lecturer in civil engineering at the University of Southampton and co-author of the study, ruled out a link between last winter’s devastating floods and climate change.
However, the Met Office does not agree, and Dame Julia Slingo, its chief scientist, said “all the evidence suggests there is a link” with global warming.’
As Bloke down the pub says, the EU Water Directive & Habitats Directive are the two primary drivers for returning historically drained land to flooding, rigidly enforced by the eco-nuts at the Environment Agency (not a patch on the draconian one in the USA – yet!)! This was deliberately kept quiet by the EU infected BBC News channels, but they did grudgingly mention that “some” parts of the levels were not dredged sufficiently. May I remind people that these brackish areas are ideal breeding grounds for malaria bearing mosquitoes, so they are already creating the self-fulfilling prophecy of potentially more malarial outbreaks in the UK , (traditionally known as the “ague” & is mentioned in many a Shakespeare play) which they can then attribute to Global Warming! Nice job! Interestingly the eco-nazis tried to blame ever increasing costs of insurance on AGW after such events. They neglected to mention a change in policy adopted some time ago by the UK insurance industry, of “New” for “Old”, whereas in the past a value would have been placed on damaged goods/property etc, & they would only pay out on part of the “New” value. Apologies if repeating myself, but my best mate & his wife were flooded out some years ago as the result of a local farmer’s poor land management practice. Their two lovely sofas had the covers stained brown by flood water. The insurance guy told them they would replaced as they had a new for old policy. They were perfectly serviceable, & Helen said she was just going to wash the covers & die them a different colour!
It interests me that flooding, storms etc are called ‘natural disasters’ when in fact they are ‘human disasters.’ Flooding has always been a part of ecosystems. It is only when it interacts negatively with houses built in the way that it is a problem. A bit like the problems caused when you build a city below sea level and find it doesn’t cope well when a hurricane runs into it.
As I recollect some of the flooding, particularly in the Somerset Levels, was deliberate in order to provide more habitat for birds.
http://www.telegraph.co.uk/comment/columnists/christopherbooker/10625663/Flooding-Somerset-Levels-disaster-is-being-driven-by-EU-policy.html
http://www.telegraph.co.uk/earth/flooding/10655005/The-flooding-of-the-Somerset-Levels-was-deliberately-engineered.html
Baroness Young, a Labour peer was appointed to the job of CEO by the then Labour government following a spell as CEO of the Royal Society for the Protection of Birds.
Not that she had a record of protecting birds from wind turbines while she was running the RSPB.
Old’un says:
August 20, 2014 at 3:59 am
However, the Met Office does not agree, and Dame Julia Slingo, its chief scientist, said “all the evidence suggests there is a link” with global warming.’
This from the woman who claimed last year that the Wet Office’s calculations were not wrong, because they were “probablistic”! They declined to comment further when asked if they got the forecast right!
The same organisation that now states that Spring commences on 1st March, instead of the more traditional & rather quaint astrophysical Vernal Equinox!
Near me in Tewkesbury there has long been a history of flooding.
This has been made worse by the new Housing Estate built by a Birmingham Company who knew nothing of the area. To demonstrate their foolishness the company was originally called:
“Water Meadows (Tewkesbury) Management Company Limited”.
After the inevitable flooding the company changed their name to:
“Meadows (Tewkesbury) Management Company Limited”.
All the better to ensnare suckers, I suppose.
Well duh!. Wettish sort of place is the UK. Dopey bureaucrats exacerbate the problem. Might as well ponder the noses on their faces.
richard verney says:
August 20, 2014 at 3:09 am
“When housing is built on flood plains, often new flood defences are put in, so as to try and protect those new homes from flooding. However, very often this new flood defence creates a problem. By not allowing a river to flood in its usual and historic flood plain, in times of high river flow, the river backs up resulting in the river flooding in areas where historically it did not use to flood.”
———————
The “flood control” levees and dikes that have been built along the lower Mississippi River and its tributaries in the US is a prime example of the above ….. “guaranteed flooding disaster”.
When the “Spring snow melt” and the “Spring rains” begins in the upper mid-west (headwaters of the Mississippi and Missouri Rivers) the outflow channel of the lower Mississippi has been reduced so much that horrendous flooding begins in the north and progresses southward ….. and starts “overflowing” those levees and dikes as it makes its way to the Gulf of Mexico.
To wit:
The Missouri River is the longest river in North America.[11] Rising in the Rocky Mountains of western Montana, the Missouri flows east and south for 2,341 miles (3,767 km)[7] before entering the Mississippi River north of St. Louis, Missouri. The river takes drainage from a sparsely populated, semi-arid watershed of more than half a million square miles (1,300,000 km2), which includes parts of ten U.S. states and two Canadian provinces.
I was in Holland last month and we had a storm. My friend has a house built 200 years ago and has steps up to his outside doors. The new houses, built in the last 5 years, over the road didn’t. The water was 10cm or so deep. Guess who was flooded?
It’s not an unusual occurrence I lived over there for 2 years and had to dismount from my omafiets several times because making progress through what was virtually a river was impossible.
How many of these design decisions can be traced back to a belief we would all be living on an arid, scorched ball.
As mentioned at the time, presumably the ground dwelling animals, like badgers, hedgehogs, birds, & bumble-bees & the like, all drowned as a result. Smart thinking these eco-nuts possess! It always seems to be Global Warming, never Green policies that cause problems.
Reporting bias — meet confirmation bias.
Here’s where confirmation bias comes in. If the data supports a global warming narrative, it is left as-is — there is no confirmation incentive to change it. However, if it doesn’t, biased AGW scientists look for plausible “explanations”, and, where found, adjust the data.
So, uncooperative temperatures require adjusting, increasing flood data does not.
“The biggest challenge for water by a long way is the developing impact of climate change. That’s going to determine everything that happens in water policy over the next 30 to 40 years.”
Leader interview: Environment Agency chairman Lord Chris Smith
http://www.edie.net/library/view_article.asp?id=6488&title=Leader+interview%3A+Environment+Agency+chairman+Lord+Chris+Smith
Mr Liddell-Grainger said he – along with other Somerset MPs – had not been approached by Lord Smith concerning the Government’s £400,000 budget for dredging, which was insufficient.
“Why? Because the Environment Agency’s managers, with Lord Smith’s tacit approval, had already taken the view that dredging was not going to be a priority. Why else would they have sold off all the dredging equipment?
‘Smug, arrogant, self-satisfied’ – Somerset MP continues broadside at Environment Agency head
http://www.westernmorningnews.co.uk/Somerset-MP-continues-attack-smug-arrogant-self/story-20603848-detail/story.html#khgjuvSSsGq8s4Bu.99
===========
so there we have it. The EA chairman believes that Climate Change is the problem. So they sell off the dredging equipment and Somerset floods. This is the true danger of climate change. It is used as an excuse to do nothing. They reason: “Since we can stop climate change, there is nothing we can do to prevent floods. Therefore it is OK to sit back and do nothing. But of course we still need to collect a huge salary for working 2 days a week, doing nothing.”
However, very often this new flood defence creates a problem.
===========
The Fraser River in BC has dikes 60 feet tall outside of Vancouver. Over the years the river has deposited 30 feet of sediment between the dikes, such that the river bottom is now well above the surrounding land. Without regular dredging a river will always overflow the flood defences, given time.
So we have stats that show increased flooding and projections for even more flooding in high risk, flood plains.
Given these 2 choices, which one would you choose.
1. Not build houses in the higher risk flooding zones, which means some people will not make as much money but homeowners will not bear all the risk.
2. Build the homes anyway. Spend trillions to cut CO2 emissions. Now you have 2 groups that can make more money………one that has profits tied to the home building, the other tied to cutting CO2 emission.
The home owner gets screwed twice in option #2. First, taking on all the risk of having a home in a flood plain, then, having to pay much more money for energy and schemes that involving cutting CO2 emissions.
The majority of logical people would choose option #1. The minority, that are driven by money in their pockets or power grabs as the motivating force ARE choosing option #2 and providing the majority with convincing sounding reasons for why this is a good choice.
Confirmation in the UK for what Roger Pielke Jr has been detailing with respect to costs of flooding for many years. When more people live in flood-prone areas, more people report and suffer damage from flooding.
The only possible exceptions to this finding come from the incompetence of the agencies tasked with managing floods. In addition to the south west of the UK, there is a case in the US where people are suing the Army Corps of Engineers for keeping dam levels high in spite of a massive snow-pack in 2011. it seems that internal emails have revealed that the Army’s own engineers warned of the high snow pack and the need to reduce dam levels well in advance of the flooding so the case verges on negligence as much as incompetence:
http://bismarcktribune.com/news/state-and-regional/north-dakota-residents-join-missouri-river-flood-lawsuit/article_1178ac80-242b-11e4-b61e-0019bb2963f4.html
Just as well England and the Low Countries didn’t have climate change back in 1953. They reckon some of the land is still salty after that lot. Hundreds dead in England, thousands in Holland. But no climate change.
And when you consider how all Eastern Australia turned into a sodden sponge in 1950, after more than a half century of rain deficit…well, whatever they had before climate change must have been pretty potent.
And that inland sea which formed to the west of Sydney in 1956, size of England and Wales? All presumably done without climate change, just like our driest known year, which was 1902. And our most lethal heatwave, 1939 (a La Nina, for God’s sake!). And the world’s greatest known inferno, in Victoria in 1851. And Cyclone Mahina, 1899…
All done without climate change!
Not at all surprising – yet another way in which a higher population makes our quality of life increasingly poor. And yet our government continues to allow in large numbers of unskilled labourers who are of no use to an economy already over stuffed with them.
We need to acknowledge the hard truth – that unless people have a skill to bring in they are worse than useless and can only be a burden.
clovis said;
‘My friend has a house built 200 years ago and has steps up to his outside doors. The new houses, built in the last 5 years, over the road didn’t. The water was 10cm or so deep. Guess who was flooded?’
I think you might find that the increasingly mad rulers of the EU have banned steps on new builds because of the lack of disabled access they offer. I have seen new houses here in the UK without them and the rain builds up on the road and pours straight in to the houses.
tonyb
A higher exposure to _insurance companies_ will result in more reported flood events
“UK flooding tied to proximity of urbanization and population growth”
Duh!!!
Roger Dewhurst says:
August 19, 2014 at 9:44 pm
Surely it does not require an academic to tell us that the denser the population the greater the risk of people being affected by a flood.
__
It’s not just that though, if you use more and more rain gauges, are you not going to measure more rain? 😛