'how to tackle cliff erosion'
Futures Forum: Beach Management Plan for Sidmouth
here's a photo from the 2009 storms in Dorset:
Chesil Beach - Hurricanes and Storms - Geology Field Guide by Dr. Ian West
and, in the wake of the latest storms, here's an interesting piece in the Independent from Boyd Tonkin about the science of beach management:
How man and nature did battle on Chesil Beach
Recent storms have dredged up debris from usually clear waters
Friday 10 January 2014
Friday 10 January 2014
“All systems fail. Discuss.” In the bar of the Cove House Inn, in Chiswell, at the end of Chesil Beach, Geoffrey Poole remembers with a chuckle an exam question from his student days at Cambridge. Looking every inch the boffin, with his silver halo of hair, the geomorphologist, an expert on the ever-shifting Dorset coastline, sits me down for an impromptu seminar on storm patterns, flood defences – and why the media gets them so wrong. Around us, as handy visual aids, hang framed historic photographs of storms and floods far more overwhelming than this week’s was. This time, Mr Poole insists, the system did not fail: “It was a huge success story.” Forget the doom-laden allusions to biblical inundations that accompanied TV images of the monstrous seas. At least for the moment, apocalypse was delayed on Chesil Beach.
You may well have seen the inn, and the giant waves of the cove around it, on news bulletins earlier this week. The gales that lashed Chesil and Portland served as a photogenic coda to a season of extraordinary tempests. At the climax of a fortnight of wild and stormy nights, the flood-warning siren sounded on the Isle of Portland at 10pm on Monday. Another deluge coincided with high tides and winds that gusted up to 80 miles per hour.
An 18-mile stretch of flint and chert shingle, Chesil Beach curves down towards the vast rock lion of Portland – the headland that Thomas Hardy called “the Gibraltar of the north”. Over the centuries, the beach has attracted almost as many seekers after symbolic landscapes as the White Cliffs 150 miles to the east. These shores carry a weighty cargo of history and myth: from the rising sea levels at the close of the last Ice Age which first fashioned them, through the role of Jurassic Coast fossils in the geological challenge to biblical creationism, up to the epic fleet that mustered in Portland Harbour prior to D-Day. When I interviewed Ian McEwan in 2007 about his novel On Chesil Beach, he remarked that this “infinite shingle” offered “so many metaphorical possibilities”. He had to rein them in; otherwise, “they could kill the novel”.
In recent days much of the media have shown no such restraint. Today, under bright blue skies and in a breeze that almost feels caressing, a tramp along the beach does bear witness to the sea’s power. Until last week, the pebbles formed a succession of low ridges or terraces. Now wind and wave have flung them back into a steep slope, with, on the other side, a longer, gentler descent towards the village. A dramatic stone escarpment now stretches north-west towards the far horizon. Its high crest is flecked by the random rubbish thrown up by even this most pristine-looking sea. Large pebbles chucked with abandon over the wall tumble down towards the houses. Further south on Portland, the ancient stack of Pom Pom Rock simply collapsed. At the Chesil Beach Centre, managed by Dorset Wildlife Trust, assistant warden Angela Thomas drily comments that the latest storm “gave you a good understanding of the true force of the sea”.
On a tablet, she shows me pictures of the new hollows, or “canns”, gouged out by the waves. Near here, some sections of big pebbles have been swept away and replaced by a fine gravel. The elements have picked up thousands of tons of stones and reshaped them like a toddler in a sandpit. Yet Portland and Chesil are not disaster zones today, despite our craving for apocalyptic meteorology.
“The emotionalism of the press was ridiculous,” says Geoffrey Poole back at the Cove House Inn. He praises the pub’s co-landlady Jackie Breakspear, who went on Channel 4 News to douse the hysteria with a dose of fact. Could it be that our dread of climatic catastrophe, however well founded it may be, has sharpened an appetite for what you might call “weather porn”? And perhaps a surplus of such scary tales will distract attention from the science of rational preparation – and the history of natural recovery. Both are in evidence on Chesil Beach.
Yes, the recent storms have reconfigured the shingle. But that has happened many times before, and will happen many times again. Angela Thomas, who has worked around the beach for 16 years, notes: “The shore is usually changing its shape. It’s not uncommon.” It turns out that this apparently epochal transformation in fact forms part of a geological routine. “It was a very spectacular storm,” she says, “but perhaps not as dramatic as people made it out to be. There will be visual impacts that remain. But in a couple of weeks, the structure of the beach will have changed again.” In due course, she expects, “Chesil will rebuild itself.” Geoffrey Poole sums up the beach as a “dynamic, permeable” system – more of an ever-changing creature than a stick of rock.
Memorable storms have battered this long bank, the “great protector” of Weymouth and Portland Harbour, over many centuries. In 1824, an especially devastating spring-tide surge drowned perhaps 50 people here. The shingle was “overtopped all the way along”, explains Mr Poole. “A schooner was shot over the top of the beach.”
Geologist Ian West, who charts the stormy history of the coast, calls the 1824 event “perhaps a storm in 1,000 years”. This week, Dr West told me that the most recent gales don’t come remotely close to the “almost tsunami effects” of 1824. In his judgment, “The recent storm was not the great event”, although it might conceivably have been a “one-in-50 years” occurrence. Nonetheless, he warns against complacency: “The relative frequency of bad weather with very heavy rainfall is bound to have further effects. There will be many new cliff falls and evidence of coast erosion. There will be risk.”
Later surges shook the coastline at regular intervals. This century, they took place in 1942, 1954 and then – in a double whammy of a storm surge followed by an ocean swell – in the winter of 1978-79. Geoffrey Poole contrasts the “destructive sea” witnessed this week – which, paradoxically, does less harm – with the “constructive sea” of 1979. In such a case, “the waves come swelling in and break everything in front of them”. When he mimics the action of the relatively innocent “destructive sea”, he makes a clawing, scratching movement with his hands. Before Ian McEwan, the most famous fictional depiction of these shores came in Thomas Hardy’s novel The Well-Beloved (1897). In that book, Hardy repeatedly describes the seas of Chesil and Portland as “canine” in their motion. At last, that doggy metaphor makes sense to me.
After the flooding of February 1979 – a true winter of discontent – the reinforcement of coastal defences at last became a priority. “For once,” Mr Poole recalls, “someone really applied themselves to the problem.” And the solution, a sea defence system completed in 1986, involved not only building walls but digging holes. Making use of the difference in high-tide times between Chesil Beach and Portland Harbour, and aided by research at the (then) Middlesex Polytechnic, an engineering firm designed a tunnel and channel between the two as a storm drainage outlet. Some locals objected to this interceptor drain in a World Heritage Site as a “monsoon ditch”. But it was built. And earlier this week, “the tunnel worked beautifully”. What’s remarkable is not how much damage the wild weather caused, but how little. “If you’re looking for a hero,” says Mr Poole, “then it’s that firm.”
I’m reminded again of McEwan, whom I once saw lecture at the University of East Anglia on the perilous allure of “end-time” thinking. We love apocalyptic tales to make our flesh creep, he argued. And it could be that this taste for millennial calamity in narrative renders us less willing or able to avoid it in reality. At length, even the sturdiest systems will fail. In Dorset, Ian West foresees that “it is quite possible that one day the evacuation of the seafront and other low parts of Weymouth may take place”. Still, we would benefit from more intelligent defences, and fewer fantasies of doom. McEwan is also a stalwart champion of the scientific reason that (for example) converts tidal disparities between almost adjacent waters into a potentially life-saving fix.
In the long term, no amount of human ingenuity will withstand the slow, relentless push of ocean against stone. “Eventually,” explains a panel at the visitors’ centre, “Chesil Beach will break up, exposing the land behind to the full power of the Atlantic storms.” Geological time, whether accelerated or not by climate change, has absolutely no respect for human clocks.
Ian West’s future “great event” – the Jurassic Coast equivalent of California’s “big one” earthquake – lies patiently in wait. For the span of our societies, however, intellect and ingenuity can still help to keep those mutinous elements at bay. The storms that flayed the Dorset coast this week revealed a story not just of frail humanity humbled by nature’s power, but of foresight, preparedness – and elegant engineering solutions. In the end, we saw not a disaster movie but a sort of scientific romance. Ian McEwan would surely approve of that.
How man and nature did battle on Chesil Beach - Comment - Voices - The Independent