AZ 
  
The coastline in north east Brazil is structurally controlled. On 
the steep sandstone cliffs, where the fracture density is less, than 
on the low quaternary shorelines, the erosion rates is about 150 
meters over 25 years. Recent tectonic activity along in the 
coastal areas may be linked with the lineaments mapped from the 
RADARSAT images. 
4. CONCLUSIONS 
This paper has shown that RADARSAT images can be used to 
measure coastal changes in permanently cloudy tropical shorelines. 
e In the flat permanently cloudy coastal areas of Guyana and 
north east Brazil, RADARSAT S7 image is particularly 
useful to map areas of erosion, as well as the adjacent 
affected coastal land use, at a scale of 1:100 000. The 10 
metre fine mode of RADARSAT with incidence of 36-48 
degrees will be suitable to map coastal changes at a scale of 
1:50 000. 
e In north east Brazil coastal erosion is controlled mainly by 
geology and geomorphology. On fractured quaternary 
sediments erosion rates vary from 0 to 12 meters a year, 
and more resistant sandstone erosion rates vary from 0 to 6 
meters a year. 
e In Guyana, low flat areas below sea level erosion rates vary 
from 0 to25 meters a year. 
e In El Niño year, these estimates are expected to increasc. 
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