Journal of Coastal Research, Special Issue 56, 2009 Journal of Coastal Research SI 56 1199 - 1203 ICS2009 (Proceedings) Portugal ISSN 0749-0258 Integrating Geological Knowledge in Planning Methods for Small Islands Coastal Plans R. Coutinho†, J. Pacheco†, N. Wallenstein†, A. Pimentel†, R. Marques† and R. Silva† †Centro de Vulcanologia e Avaliação de Riscos Geológicos, Universidade dos Açores, Portugal Rui.MS.Coutinho@azores.gov.pt ABSTRACT COUTINHO, R., PACHECO, J., WALLENSTEIN, N., PIMENTEL, A., MARQUES R. and SILVA, R., 2009. Integrating Geological Knowledge in Planning Methods for Small Islands Coastal Plans. Journal of Coastal Research, SI 56 (Proceedings of the 10th International Coastal Symposium), 1199 – 1203. Lisbon, Portugal, ISSN 0749-0258. The Azores archipelago lies in the junction of the North-American, African and Eurasian lithospheric plates. The geodynamical setting is therefore complex and, consequently this area is affected by intense seismic and volcanic activity. This study addressed the coastal geology of four Azorean islands: Santa Maria, Graciosa, Flores and Corvo. The coastlines studied exhibited a diversity of littoral types, with distinct lithologies and morphologies. Coastlines are socio-economically very important in any archipelago. Therefore, it is imperative that land-use management methodologies are implemented in these vital areas. This need is further justified by the natural seismic and volcanic vulnerabilities of these islands, which makes hazard assessments absolutely fundamental. It is this knowledge that will later inform our policies and methodologies of risk mitigation, sustainable development and land management planning. This study analyses two aspects of this problematic: geological characterization and hazard assessment. Special attention must be paid to the geomorphology, volcanic features, tectonic structures, lithology, hydrology, coastal stability and erosion patterns of these areas. Risk assessments of seismic, landslide and tsunami events were undertaken and used as a reference in the formulation of the Coastal Zone Management Master Plans for the above-mentioned islands. After the Hazard Assessment was concluded, the Geology team along with the Planning team, built up a Management Map, a Constraints Map and the corresponding legal rules that ought to be applied in these domains. ADITIONAL INDEX WORDS: Coastal zones, Geological hazards, Management Master Plans, Azores. INTRODUCTION The Azores archipelago is located on the North Atlantic, between 36º 55’ and 39º 44’ N latitude, and 24º 46’ to 31º 17’ W longitude. It consists of nine volcanic islands dispersed along more than 600 km in a NW-SE trend. The Azores lies in the junction of the North American, Eurasian and African lithospheric plates (Figure 1). Due to this peculiar location some of the islands are affected by seismic and volcanic activity. Since its settlement, in mid 15th century, the Azores have been affected by more than 20 major earthquakes that caused more than 5000 deaths and severe destruction. There are also records of at least 27 historical volcanic eruptions, either inland or at sea. The last volcanic events occurred in 1957-1958 at Capelinhos, Faial Island, and in 1998-2001 offshore Terceira Island. Annual rainfall of 1000- to 5000- mm is distributed over the year, with a dryer period from June to September. Landslides caused by heavy rainfalls are not uncommon. One of the more recent events affected all of the eastern part of S. Miguel Island, after a succession of rainy days that culminated with a record rainfall of more than 200 mm in 24 hours, causing 27 fatalities. In other situations the natural weathering of the rocks combined with some events like heavy rainfalls, strong winds or earthquakes may potentiate critical situations. The islands have witnessed considerable socioeconomic development. This led to increasing pressure on coastal areas and surrounding territories. In order to execute an adequate land-use management plan, within the present legal framework, the government of The Azores issued the Regional Legislative Decree Nº 18/98/A, dated November 9th that sets the principles to be observed for Coastal Zone Management Master Plans (CZMP) for the Azores Autonomous Region. Its main recommendations are: protection of the biophysical integrity of the space; evaluation of the coastal resources and preservation of landscape and environmental resources. The Regional guidelines concerning coastal interventions are defined in the Resolution Nº138/2000, dated August 17th, which sets as a priority the protection and safety of human lives and belongings. The present work results from the investigative efforts of its authors in the geological characterization and evaluation of natural hazards. The authors of this study are members of the team that carried out the CZMP of several islands of the Azores. 1199