Up to six metres of coastline claimed by the sea each year: Some coastal defences can cause erosion on nearby beaches, scientists warn. Nicholas Schoon reports

Click to follow
The Independent Online
PARTS of Britain's coastline are being eroded at rates of up to six metres a year. Each year there are large coastal landslips on the same scale as the one destroying Holbeck Hall Hotel in Scarborough, North Yorkshire.

Yet they rarely make the headlines because fields rather than homes are destroyed. Coastal stretches prone to collapse are sufficiently well known to be off limits to builders.

Yesterday, as the North Yorkshire MEP Edward McMillan-Scott called for emergency EC aid for Scarborough, scientists warned that coastal defence structures used to combat erosion could cause problems further along the coast.

Dr John Pethick, a coastal geomorphologist at Hull University, said the best overall solution was to avoid building in the worst affected areas, surrender land to the sea and compensate landowners affected.

He said compensation should be sorted out at a European level because huge quantities of sediment from Britain's east coast travelled across the North Sea to be deposited on the beaches of Belgium, the Netherlands and Germany. Once there it acted as a natural sea defence.

Dr Pethick said a 25-mile stretch of coast around Holderness, north of Hull, was being eroded at the rate of 2 metres a year, depositing about 1.5 million cubic metres of sediment into the North Sea.

Since Roman times the coast has moved more than two miles inland and some 30 villages have disappeared. Professor Keith Clayton, head of the University of East Anglia's school of environmental sciences, said the erosion rate along a three-mile stretch at Covehithe, north of Southwold in Suffolk, was even higher - six metres a year for several decades. In one location the sea had come inshore by 35 metres during a recent winter.

He said there had been many cases of piecemeal coastal defence works being built this century which caused severe erosion further afield.

On some stretches of coastline one cliff edge can be eroding rapidly while a low-lying area one mile away can be fed by the sediment from it and be in peril should that supply be interrupted.

The southern half of Britain is gradually sinking - as fast as six millimetres a year - while the north is rising: the axis runs between Belfast and Sunderland. This happens because the land mass is still responding to the removal of billions of tons of ice at the end of the last Ice Age 10,000 years ago.

At the same time, global sea levels may be starting to rise slowly as the sea warms, due to the increase in temperatures brought about by increasing levels of man-made 'greenhouse' gases. Dr Pethick said the rise was happening at about one millimetre a year. The east coast is affected worse than the west because the rocks tend to be softer.

The new thinking is to surrender land wherever possible and to imitate or encourage natural defences, such as beach building.

The Ministry of Agriculture, which has the prime responsibility for coastal defence, is interested. But it has yet to come up with any large-scale trials, or compensation schemes for landowners affected.

(Photograph and map omitted)