MAPPING AND MONITORING THE INTERTIDAL ZONE OF THE EAST-COAST OF ENGLAND USING REMOTE-SENSING TECHNIQUES AND A COASTAL MONITORING GIS

The paper compares two different techniques for mapping the intertidal zone of the Wash estuary on the East coast of the United Kingdom using Landsat 5 thematic mapper (TM) satellite imagery. Two scenes from different dates were processed using a conventional maximum likelihood classifier and a fully constrained linear mixture model. The Landsat TM data was atmospherically and radiometrically corrected to allow meaningful comparison to be made between the scenes. The data were geometrically rectified and incorporated into a coastal monitoring Geographical Information System (GIS) along with information acquired from previous ground based surveys. The relative accuracy of two mapping procedures was assessed by cross tabulating the satellite imagery with ground based surveys. The results show that both classification techniques adequately delimit over 90% of the intertidal vegetation. However, both methods had difficulty in discriminating between the Pioneer zone vegetation and intertidal sediments. Linear unmixing appeared to be the most accurate method for mapping pioneer zone vegetation and this should form the basis of further research.