Examinando por Materia "Caribbean Coast"

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    Ítem
    Introducción al problema de la erosión litoral en Urabá (sector Arboletes - Turbo), Costa Caribe Colombiana
    (Instituto de Investigaciones Marinas y Costeras - INVEMAR, 2004) Correa-Arango, Ivan D.; Vernette, Georges; Universidad EAFIT. Departamento de Geología; Ivan D. Correa (icorrea@eafit.edu.co); Ciencias del Mar
    Introduction to littoral erosion problem in Urabá (Arboletes-Turbo area) Colombian Caribbean coast. Shoreline retreat has been the net dominant historical trend along the 145 km-length littoral between Arboletes and Turbo (Southern Caribbean of Colombia). For the last four decades, there were identified in this littoral shoreline retreats of about 50-100m in several places (Uveros, Damaquiel, Zapata, Turbo) and a maximun of 1.6 km in the Punta Rey-Arboletes area, where land losses were of 4.5 k m2, at exceptional rates of 40m/year. The synthesis of the available information suggest that the general “susceptibility” to erosion between Arboletes and Turbo could be related primarily to relative sea level rise, associated to tectonic movements as well as to the effects of mud diapirism and hydroisostacy. In the more critical areas (Arboletes, Turbo), the natural erosive trends were accelerated by anthropic actions, including river diversion (Turbo), beach mining, and inadequate (or total absense) practices for controlling residual and natural waters. Up to August 2000, there were invested about $ Col 10.000 billions in 155 engineering defences (groins, sea walls and rip-rap which totalize 6.2 km of total length and a volume of materials of 37.000 m3). With few exceptions, groins have not been successful and are now part of the problem, accelerating shore erosion along the adyacent sectors. In the short term, the littoral erosion between Arboletes and Turbo is caused both by marine and by subaerial factors. It is facilitated by the poor lithological strengths of cliffs and marine terraces, mainly composed of highly fractured and weathered claystones and mudstones (with stratification and weakeness planes dipping toward sea) and nonconsolidated, easily liquefacted, fine sediments; both conditions facilitate the occurrence of rocks falls, slides and mud flows that result in high figures of cliff retreat (3 to 4m), specially during the first 15 days of the summer-winter transition (april) and in high waves periods. The case of the littoral erosion between Arboletes and Turbo illustrates well how the natural erosive trends of an area can be accelerated by human interventions and the urgent need for coordinating efforts to cope with littoral land losses.
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    Ítem
    Shore erosion between Arboletes and Punta San Bernardo, caribbean coast of Colombia
    (Universidad Industrial de Santander, 2007-07-02) Correa-Arango, Ivan D.; Ríos, A; González, D; Toro, M; Ojeda, G; Restrepo, L; Universidad EAFIT. Departamento de Geología; Ivan D. Correa-Arango (icorrea@eafit.edu.co); Ciencias del Mar
    The present morphology and the inventory of the historical shoreline changes (1938-2005) between Arboletes and Punta San Bernardo evidenced a strong erosional trend along 160 of its 180lan tota1-1ength, resulting in the disparition/retreat of numerous beaches, followed by the consequent flooding/erosion of the adjacent littoral terraces and mangrove swamps. In general terms, the littoral Arbo1etes-Punta San Bernardo retreated 30 to 100m during the last seven decades, at rates between 0.5 and 1.5 m/year; maximum values were found at some critical sectors in the Arboletes-Punta Brava shore segment where magnitudes of coastline retreat were in the order of 900-1.500m at erosion rates up to 70 m/year during the period 19601975. Shore erosion in the study area results both from marine and subaerial processes and the combination of geological factors (neotectonism and effects of mud diapirism, minor stocks of sands, relative sea level rise, poor geotechnical characteristics of cliff's rocks) and human interventions (intensive sand mining from beaches and rivers, land uses with inadequate water management practices, adverse effects of groins and other rigid structures of defense). The precise definition of each one of these factors is necessary for planning the development of the area considering the future sea level rise associated to the Global Climate Change.