Evaluación del riesgo de inundación a múltiples componentes en la costa del Maresme

The coast is one of the areas most affected by natural hazards, with floods being the most frequent and significant of these in terms of their induced impacts, so any management scheme requires their evaluation. In coastal areas, flooding is a hazard associated with different processes acting at different scales: coastal storms, flash floods and sea level rise (SLR). To address the problem as a whole, this study presents a methodology to undertake a preliminary integrated risk assessment of the magnitude of each flood component, taking into account their scope (extension of the affected area) and their temporal scale. The risk is quantified using specific indicators to assess the hazard magnitude (for each component) and the consequences. This allows for a robust comparison of the spatial risk distribution along the coast in order to identify both the most at-risk areas and the most influential risk components. This methodology is applied to a stretch of coastline (Maresme, Catalonia) representative of the Spanish Mediterranean coast. The results obtained characterise this coastline as an area with a relatively low overall risk, although some hotspots are identified as having high-risk values. Resumen: La costa es una de las zonas más sometidas a riesgos naturales, siendo la inundación uno de los más frecuentes e importantes en términos de daños inducidos, por lo que cualquier esquema de gestión requiere evaluación. La inundación en zonas costeras es una amenaza natural asociada a diferentes procesos que actúan a distintas escalas: tormentas costeras, riadas y subida del nivel del mar (SNM). Para abarcar la totalidad del problema, este trabajo propone una metodología para la evaluación preliminar del riesgo integrado de inundación costera a una escala regional que permite evaluar la magnitud de cada componente teniendo en cuenta su alcance (extensión de la zona afectada) y su escala temporal. El riesgo se cuantifica en función de unos indicadores específicos que valoran la magnitud de la amenaza para cada componente y las consecuencias. Esto permite comparar robustamente la distribución espacial del riesgo a lo largo de la costa, para identificar tanto zonas de mayor riesgo como las componentes que más contribuyen al mismo. Aplicamos esta metodología a un tramo de costa característica del Mediterráneo español (Maresme, Cataluña). Los resultados permiten caracterizar esta costa como un área con un riesgo global relativamente bajo, pero algunos puntos singulares con riesgo alto

Signy Island

Signy Island (lat. 60° 43' S, long. 45° 38' W) is one of the southernmost and smaller members of the South Orkney Islands, which lie in the South Atlantic Ocean on the southern arm of the Scotia Ridge. It has a total surface area of about 20 km2, a greatest length (from north to south) of 8 km, a maximum width of 5 km and a highest elevation of 280 m. The north point of the island is only 1.5 km distant from Coronation Island, largest of the South Orkney group. In outline Signy Island is roughly triangular (figure 1) but the coastline, which is mostly cliffed, is indented by bays, and projects in numerous narrow headlands. Along the western coast there is a strip of lowland which shows prominent terraces, probably of marine origin, at the 30 to 60 and 80 to 100 m range. On the north-east and south-east there are other lowland areas with a more mammillated topography. The uplands of the island are roughly cruciform in plan, the main axis running NNE-SSW from Robin Peak to Snipe Peak on Moe Island and the east-west arm extending from Jebsen Point through Garnet Hill to Rusty Bluff. All these summits are flat topped and reach a rather uniform elevation of 200 to 280 m. The topography as a whole is rugged (figures 2, 3, plate 15) and reflects the combined influences of structure, marine erosion and glaciation, the latter being dominant. There are numerous cirques about the margins of the highland, and extensive moraine and outwash deposits on the lower ground. Locally, as in Three Lakes Valley and inland from Cummings Cove these deposits mask the underlying relief of the bedrock surface

Biological research by the British Antarctic Survey

The Antarctic Peninsula, the islands rising from the Scotia Ridge, and the Falkland Islands are a key area for biologists interested in the origin, relationships, and adaptations of the Antarctic flora and fauna. Of all Antarctic regions, furthermore, this has perhaps been the most intensively studied. The pioneer observations of J. R. and J. G. Forster during Cook's circumnavigation in 1772–75, and of James Eights in 1833 (Caiman, 1937), supplemented by the less systematic accounts of those engaged in early nineteenth-century sealing and whaling voyages (Weddell, 1825; Allen, 1899) paved the way for the thorough scientific programmes of more modern expeditions. The first of these, the Belgica expedition under de Gerlache, 1897–99, yielded much general information and brought back an apterous fly {Belgica antarctica),the first higher insect to be discovered in the true Antarctic. Soon afterwards, the Swedish South Polar Expedition led by Nordenskjold, 1901–04, brought to the Antarctic an outstanding botanist, the late C. J. F. Skottsberg, whose botanical researches on Antarctic and sub-Antarctic themes were to last for over half a century (Skottsberg, 1963). During the following decade the two French expeditions led by Charcot, 1903–05 and 1908–10, contributed important microbiological and ornithological information, and in 1902–04 the Scottish National Antarctic Expedition under Bruce made the first study of the South Orkney Islands and provided a general evaluation of botanical and biogeographical problems (Rudmose Brown, 1912). All these expeditions made general collections of flora and fauna which revealed that the Antarctic Peninsula and its adjacent islands were the richest area, biologically speaking, of the whole Antarctic region. Farther north, the Swedish Magellanic Expedition, led by Skottsberg in 1907–09, provided what is still the only published account of the vegetation of the Falkland Islands and information vital to the evaluation of biogeographical relationships between the Scotia Ridge, the Antarctic Peninsula, and the Magellanic region of South America. Skottsberg (1912) also described the vegetation of South Georgia, where pioneer work had been done by Will during the German International Polar Year expedition, 1882–83. The botanical work on this island, up to 1964, has recently been comprehensively reviewed by Greene (1964a)

Observations in the South Sandwich Islands, 1962

The South Sandwich Islands lie between lats. 56° 18′ S. and 59° 28′ S., and between longs. 26° 14′ W., and 28° 11′ W. There are eleven islands, of which ten form a curved chain stretching north and south while the eleventh, Leskov Island, lies to the west of the group near its northern end. The group is the only typical volcanic island arc in the Antarctic region and forms the easternmost section of the Scotia Arc; to the east it is bounded by the associated deep South Sandwich Trench

The Antarctic ecosystem

The aim of the present paper is to summarize the broad scope of this Discussion and to attempt to draw certain final generalizations about the Antarctic as a biological zone. It is almost impossible to omit all mention of the sea from a discussion of Antarctic biology, and consequently a review of Antarctic oceanography and of food chains and biomasses at the various marine trophic levels will be given first. This leads in turn to a consideration of the interrelationships between sea, land and fresh water, and thence to an assessment of the total ecosystem