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ABSTRACT
LAMEIRAS, G., FONTIELA, J., BORGES, P., CALADO, H., VIEIRA, O., RANGEL, B. and GALLAGHER, A., 2009. Coastal hazards of Fajã do Calhau (São Miguel - Azores): a first approach. Journal of Coastal Research, SI 56 (Proceedings of the 10th International Coastal Symposium), 827 - 831. Lisbon, Portugal, ISSN 0749-0258.
Fajã do Calhau is a supratidal talus-platform located on the South-East coast of São Miguel Island (Azores). Locally called "fajãs", these flat platforms with hummocky surfaces result from landslides and are relatively common coastal features in the archipelago, occurring on the toe of the cliffed coasts of most Azorean islands. Fajã do Calhau is at the foot of a 380 m high cliffand has an area of approximately 220,000 m2, circa 1300 m length and maximum width of 260 m. The seaward margin of the fajã consists of a scarped active bluffwith modal and maximum elevations of 5 and 10 m above sea level, respectively. A gravel beach leans against this bluff. Fajã do Calhau attracted, in recent past, human settling due to its agriculture potential, in spite of the hazards arising from storms and landslides. Nowadays, this area is again increasing in value and attractiveness but as a result of the demand for second housing and seasonal leisure activities. This lead to the on-going construction of a new accessibility, which will further increase the human occupation rates both in space and time.The main coastal hazards of the Fajã do Calhau are coastal erosion (with present-day rates of 0.20 m/yr), coastal storms, mainly from SW, and coastal flooding (on average once every 7 years). Besides these, others with larger recurrence intervals, such as the ones inherent to the genesis of both this feature - landslides and earthquakes - and island volcanism.
ADDITIONAL INDEX WORDS: coastal erosion, coastal storms, coastal flooding, set-back lines.
INTRODUCTION
More than 50% of world's coasts are threatened by development (PHILLIPS, 2007 personal communication). By 2020, 75% of the world's population will live within 60 km of the coast (FINKL and KRUEMPEL, 2005).
Coastal communities are more vulnerable to climate change because in addition to meteorological parameters they are also affected by changes in oceanic parameters, especially increases in sea level and wave heights that will, in some cases, represent physical,...