Assessment of coastal change with the aid of photogrammetric and computer-aided techniques

Abstract

The study of landforms is peculiarly placed to take advantage of photogrammetric techniques. The coast and the nearshore zone include landforms where the operation of both marine and terrestrial processes produce changes more rapidly than elsewhere. At the same time this interface between land and sea also introduces special difficulties in topographic survey and the recording of changes. The present paper gives two examples where photogrammetry has been of critical importance in recording and interpreting coastal change. Both examples are taken from the south west peninsula of England. At Bridgwater Bay, Somerset, a low marsh coast is fronted by a very wide intertidal zone in consequence of the fact that the tidal range is one of the highest in the world. This introduces problems which only photogrammetry can adequately solve. Deep mud inhibits conventional ground survey and problems of access make interpretation on foot a matter of great difficulty. In Barnstaple Bay, a rocky coast with steep cliffs and relatively narrow shore platforms cut in steeply dipping rocks, introduces contrasting problems and solutions.