winter�*s the most anxious time for those at risk from coastal erosion. here at sandy bay in east devon, a huge section of land fell away last week with holiday caravans just metres away. but land slips can occur all year round. last spring, what was said to be the biggest in 60 years saw a major collapse on dorset�*s jurassic coastline. our foreshores are constantly changing. to understand what forces are at play in reshaping them, researchers from the university of plymouth studied the cliffs, dunes and sands at perranporth on the north cornwall coast. this is ourfavourite beach. we�*ve come here already for 15 years and we survey the whole beach every month. the beach here is 3.5 kilometres long, and a severe winter storm can shift up to one million cubic metres of sand out to sea before summer tides bring it back again. the beach isn�*tjust popular with visitors, but it�*s essential to protect the town.