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Ítem Ambientes de acumulación y foraminíferos bentónicos de la Formación Tubará (Plioceno del Valle Inferior del Magdalena(Universidad Industrial de Santander, 2007-01-01) Martinez, Jose Ignacio; Universidad EAFIT. Departamento de Geología; Ciencias del MarÍtem APORTES AL CONOCIMIENTO D ELA EVOLUCIÓN GEOLÓGICA DE LAS CUENCAS ATRATO Y SAN JUAN DEL ARCO PANAMÁ-CHOCÓ(Universidad Industrial de Santander, 2009-12-01) BEDOYA, OSCAR GEOVANY; Universidad EAFIT. Departamento de Geología; Ciencias del MarÍtem The Arboletes-Punta Rey Littoral, Southern Caribbean Coast(SPRINGER, 2016-01-01) Arango, I.D.C.; Paniagua-Arroyave, J.F.; Universidad EAFIT. Departamento de Geología; Ciencias del MarThe Arboletes-Punta Rey littoral is a 5.5-km-long stretch of coast located at the southern Caribbean coast of Colombia, 80 km by car (paved road) to Monteria. Geologically, it is located at terrains of the Sinu folded belt, a tectonically active sedimentary wedge evolving under the morphogenetic influence of numerous onshore and offshore manifestations of mud diapirism. It has a tropical climate. During the dry season (December-April), the zone is under the influences of the N-NE Trade winds that generate swells with wave periods between 6 and 9 s and significant wave heights up to 2 m. These waves are strongly modified by the serrated contours of the coastline and are rapidly eroding the beaches and littoral rocky formations of the area. During the wet season, the trade winds are replaced by lighter, 2-4 m/s, S to SW winds that generate seas with significant wave heights of up to 0.6 m. Net sand drift during the year in the area is toward the SW. The Arboletes-Punta Rey landscape is configured by an emerged marine terrace, a diapiric dome with active mud volcanoes, and by cliffs and their associated erosional features including caves, arches, stacks, and scarps of mass movements. These features are cut on sedimentary, highly weathered and densely fractured mudstones and shales, and in poorly consolidated diapiric muds. Besides its geomorphological interest, the Arboletes littoral is an interesting example of historical, kilometric-magnitude erosional coastline changes driven by the combination of natural-and man-induced causes including, in a short-term perspective, the poor geotechnical properties of rocks, bioerosion, absence of rainfall and waste waters management, strong wave action, beach sand mining, and inadequate coastal engineering practices.Ítem Assessing and managing scenery of the Caribbean Coast of Colombia(Elsevier, 2012-05-18) Rangel-Buitrago, Nelson; Correa-Arango, Ivan D.; Anfuso, Giorgio; Williams, Allan T.; Ergin, Aysen; Universidad EAFIT. Departamento de Geología; Ivan D. Correa-Arango (iarango@eafit.edu.co); Ciencias del MarThis study provides the coastal scenery assessment of 135 sites along the Colombian Caribbean littoral by analysing 26 physical and human factors. Sites were categorised into five classes from Class 1, top grade scenery, to Class 5, poor scenery -- Fifty five percent of the investigated coastal areas were included in Classes 1 and 2, 18% belonged to Class 3 and 47% of the sites fall into Classes 4 and 5 -- Classification of analysed sites depends on the geological setting and the degree of human occupation -- Classes 1 and 2 sites are located in natural protected areas in La Guajira and Magdalena departments -- Low classification recorded at Classes 3, 4 and 5 corresponds to a progressive decrease of both natural and (especially) human parameters -- Concerning coastal management issues, emphasis should be given to the upgrading of human parameters eliminating litter and sewage evidences, vegetation debris and enhancing beach nourishment worksÍtem Assessing and managing scenery of the Caribbean Coast of Colombia(Butterworth-Heinemann, 2013-01-01) Rangel-Buitrago, N.; Correa, I.D.; Anfuso, G.; Ergin, A.; Williams, A.T.; Universidad EAFIT. Departamento de Geología; Ciencias del MarThis study provides the coastal scenery assessment of 135 sites along the Colombian Caribbean littoral by analysing 26 physical and human factors. Sites were categorised into five classes from Class 1, top grade scenery, to Class 5, poor scenery. Fifty five percent of the investigated coastal areas were included in Classes 1 and 2, 18% belonged to Class 3 and 47% of the sites fall into Classes 4 and 5. Classification of analysed sites depends on the geological setting and the degree of human occupation. Classes 1 and 2 sites are located in natural protected areas in La Guajira and Magdalena departments. Low classification recorded at Classes 3, 4 and 5 corresponds to a progressive decrease of both natural and (especially) human parameters. Concerning coastal management issues, emphasis should be given to the upgrading of human parameters eliminating litter and sewage evidences, vegetation debris and enhancing beach nourishment works. © 2012 Elsevier Ltd.Ítem Assessing the effect of sea-level change and human activities on a major delta on the Pacific coast of northern South America: The Patía River(ELSEVIER SCIENCE BV, 2012-05-15) Restrepo A, Juan D.; Universidad EAFIT. Departamento de Geología; Ciencias del MarThis paper presents the main physical and human-induced stresses that have shaped the recent evolution of the Patía River delta, the largest and best-developed delta on the western margin of South America. During the Holocene, the Patía Delta moved southward and the northern part became an estuarine system characterized by large extensions of mangrove ecosystems. However, a major human-induced water diversion, starting in 1972, diverted the Patía flow to the Sanguianga River, and shifted the active delta plain back to its former Holocene location. This discharge diversion has led to sediment starvation of the southern delta lobe and changed the northern estuarine system into an active delta plain. In addition, coastal areas of the Patía delta subsided as a result of a devastating tsunami in 1979. Morphological changes along the delta coast are evidenced by: (1) coastal retreat along the whole delta front during the period 1986-2001; (2) coastal retreat along the abandoned delta lobe for the period 2001-2008; 56% of the southern delta shoreline is retreating and only 4% of the coast shows signs of accretion; (3) progradation of the northern delta region during the period 2001-2008; the discharge diversion of the Patía River to the Sanquianga has apparently balanced the observed trends in coastal erosion and sea-level rise (5.1mmyr -1 for the period 1984-2006, after the 1979 tsunami); (4) formation of transgressive barrier islands with exposed peat soils in the surf zone; and (5) abandonment of former active distributaries in the southern delta plain with associated inlet closure. In the northern delta lobe, major geomorphic changes include: (1) distributary channel accretion by morphological processes such as sedimentation (also in crevasses), overbank flow, increasing width of levees, inter-distributary channel fill, and colonization of pioneer mangrove; (2) freshening conditions in the Sanguianga distributary channel, a hydrologic change that has shifted the upper estuarine region (salinity<1psu) downstream; and (3) changes in vegetation succession; approximately 30% of mangrove forests in the current delta apex have been replaced by freshwater vegetation. Overall, the recent evolution of the Patía has been controlled by the interplay of (1) high basin-wide sediment load; (2) low discharge variability (Q max/Q min); (3) spatial switch of delta distributaries related to tectonic movements and subsidence; (4) a relative sea-level rise of 5.1mmyr -1 after the occurrence of the 1979 tsunami; (5) episodes of sea-level rise associated with the ENSO cycle; and (6) human-induced discharge diversion. The information presented here is valuable evidence for understanding the role of extreme events versus 'normal' conditions in creating and shaping deltas. © 2012 Elsevier B.V.Ítem Atlantic Multidecadal Oscillation (AMO) forcing on the late Holocene Cauca paleolake dynamics, northern Andes of Colombia(Copernicus GmbH, 2015-01-01) Martínez J.I.; Obrochta S.; Yokoyama Y.; Battarbee R.W.; Universidad EAFIT. Departamento de Geología; Ciencias del MarThe Atlantic Multidecadal Oscillation (AMO), is a major driving climate mechanism, in the eastern Caribbean Sea and the South Atlantic Ocean in relation to the dynamics of the South American Monsoon System (SAMS) for the late Holocene. Here we document the AMO signal in the San Nicolás-1 core of the Cauca paleolake (Santa Fé-Sopetrán Basin) in the northern Andes. Wavelet spectrum analysis of the gray scale of the San Nicolás-1 core provides evidence for a 70 yr AMO periodicity for the 3750 to 350 yr BP time interval, whose pattern is analogous to the one documented for the Cariaco Basin. This supports a possible correlation between enhanced precipitation and ENSO variability with a positive AMO phase during the 2000 to 1500 yr BP interval, and its forcing role on the Cauca ria lake deposits, which led to increased precipitation and to the transition from a igapo (black water) to a varzea (white water) environment ca. 3000 yr BP. © Author(s) 2015.Ítem Bahía de Cartagena (Colombia): distribución de sedimentos superficiales y ambientes sedimentarios(UNIV CATOLICA DE VALPARAISO, 2013-01-01) CORREA, IVAN DARIO; Universidad EAFIT. Departamento de Geología; Ciencias del MarÍtem Base de Datos Espacial Geomorfológica de la Franja Litoral Caribe de los Departamentos Antioquia y Chocó(Universidad Nacional de Colombia. Facultad de Minas, 2012-01-01) Prüssmann, Johanna; Arango, I.D.C.; Universidad EAFIT. Departamento de Geología; Ciencias del MarCon el fin de generar información para el manejo integrado y el desarrollo sostenible de la franja litoral Caribe de los departamentos de Antioquia y Chocó, se creó una base de datos espacial llamada GEOURABÁ,Ítem Base de datos espacial geomorfológica de la franja litoral de los departamentos de Antioquia y Chocó(Universidad Nacional de Colombia, 2012-08-22) Prüssmann Uribe, Johanna; Correa-Arango, Ivan D.; Universidad EAFIT. Departamento de Geología; Ivan D. Correa-Arango (icorrea@eafit.edu.co); Johanna Prüssmann-Uribe (jprussmann@eafit.edu.co); Ciencias del MarCon el objetivo de generar información esencial para el manejo integrado y el desarrollo sostenible de la franja litoral Caribe de los departamentos de Antioquia y Chocó, se creó una base de datos espacial llamada GEOURABÁ, que recopila la información geomorfológica a escala 1:10000 de los 600km del contorno costero de esta zona, a partir de la fotointerpretación y restitución de una ortofoto de la zona tomada en el año 2009. La estructuración de GEOURABÁ consideró la inclusión de 18 geoformas costeras, las cuales fueron divididas entre aquellas que están asociadas a procesos morfogenéticos depositacionales (costas bajas) y aquellas a procesos erosionales (costas rocosas). A partir del análisis de la distribución espacial de dichas geoformas, la zona de estudio fue dividida en seis sectores según las características geomorfológicas predominantes en cada uno, de los cuales tres están asociados a procesos depositacionales y tres a procesos erosionales. En esencia, el diseño y la estructuración de GEOURABÁ se realizaron a través de los siguientes pasos: a) Definición de coberturas a cartografiar; b) Diseño del Modelo Lógico; c) digitalización de coberturas; d) Cálculo de coberturas relativas; e) Asignación de Atributos; f) Diseño de reglas topológicas; g) Estructuración de Geodatabase bajo Modelo Físico; h) Diseño de salidas de productos cartográficos. En total se cartografiaron 52882 ha de territorio emergido, donde las llanuras aluviales y las colinas fueron las geoformas más predominantes (57,18% y 19,37%, respectivamente). Ecogramas de los fondos y subfondos marinos del Golfo de Urabá revelan mayores pendientes en el costado occidental que en el costado oriental, además de otras geoformas sumergidas, como plataformas, escarpes, antiformas y diapiros. GEOURABÁ procura brindar a los entes y personas relacionados con la gestión de los recursos naturales de la zona, una contextualización de la espacialidad de los tipos de costa que se presentan en la zona de estudio y las geoformas que lo componen. Con esto se pretende contribuir a la generación de un mejor entendimiento de los diferentes factores que regulan los procesos de erosión/depositación y la vulnerabilidad de la zona frente a posibles eventos relacionados con el cambio climático global.Ítem Beach Management Practices and Occupation Dynamics: An Agent-Based Modeling Study for the Coastal Town of Nags Head, NC, USA(SPRINGER-VERLAG BERLIN, 2018-01-01) Karanci, A; Velasquez-Montoya, L; Paniagua-Arroyave, JF; Adams, PN; Overton, MF; Universidad EAFIT. Departamento de Geología; Ciencias del MarThe analysis of interactions between human and natural systems is crucial for sound beach management practices. Those interactions can be simulated via agent-based modeling. Nevertheless, more work is needed to identify and understand model capabilities prior to societal implementations. This study presents the application of an agent-based model in the coastal town of Nags Head, NC USA. The case study focuses on the influence of storm arrival patterns and soft-engineering design alternatives on town occupation dynamics. The agent-based model consists of three interactive sub-models: (1) Natural Processes and Coastal Landforms, (2) Beach Management, and (3) Household Decisions. Modeling results indicate that sea level rise will exacerbate storm damages and could lead to a declining town population. In addition, analysis of occupancy with soft-engineering design alternatives suggests that population in Nags Head maximizes when economic benefits and protection from both, dunes and beaches, are balanced. Our results serve to exemplify the usage and capabilities of an agent-based model for beach management practices in coastal towns subjected to storms and sea level rise. Application of the model provides valuable insights of the system that can ultimately be used by decision-makers and town managers.Ítem Cartagena Bay (Colombia): Superficial sediments distribution and sedimentary environments(UNIV CATOLICA DE VALPARAISO, 2013-01-01) Restrepo, J.C.; Franco, D.; Escobar, J.; Correa, I.D.; Otero, L.; Gutiérrez, J.; Universidad EAFIT. Departamento de Geología; Ciencias del MarWe studied the spatial distribution and textural characteristics of 234 surface sediment samples from the Bay of Cartagena, Colombia, to understand sedimentation processes over the last few decades. We used three discriminant functions to characterize depositional environments and to differentiate among: (i) beach deposits and sediments of high-energy, shallow marine environments, (ii) fluvial deposits and sediments of shallow marine environments, and (iii) fluvial deposits influenced by turbidity currents. The predominant sediment type is a medium-size (5.35 ± 1.2 f), poorly sorted (s = 1.63 ± 0.8) mud, with a noticeable asymmetry (Sk = -0.052 ± 0.2) and kurtosis (k) of 0.84 ± 0.4. There were two main superficial sediments types in the Bay of Cartagena: (1) sediments of high-energy, shallow marine environments with high fluvial influence, and (2) turbidity current deposits with high fluvial influence. Sediments with the lowest sand content (<5%) are located along a latitudinal axis running from the Dike Channel prodelta to the western end of Tierrabomba Island. The CaCO3 content of the sediments is <10%. Autogenous calcareous sediments are covered by fine terrigenous sediment transported through the Dike Canal, which has a more active and dominant role in the Bay's sediment deposition than previously reported.Ítem A Classification System for Colombian Wetlands: an Essential Step Forward in Open Environmental Policy-Making(Springer Netherlands, 2019-01-01) Ricaurte L.F.; Patiño J.E.; Zambrano D.F.R.; Arias-G J.C.; Acevedo O.; Aponte C.; Medina R.; González M.; Rojas S.; Flórez C.; Estupinan-Suarez L.M.; Jaramillo Ú.; Santos A.C.; Lasso C.A.; Nivia A.A.D.; Calle S.R.; Vélez J.I.; Acosta J.H.C.; Duque S.R.; Núñez-Avellaneda M.; Correa I.D.; Rodríguez-Rodríguez J.A.; Vilardy Q S.P.; Prieto-C A.; Rudas-Ll A.; Cleef A.M.; Finlayson C.M.; Junk W.J.; Universidad EAFIT. Departamento de Geología; Ciencias del MarKnowledge about the distribution and diversity of wetlands has become an essential tool for environmental management and policy-making. Yet, while recent estimates indicate that 27% of the area of Colombia is covered by wetlands and despite a number of regional studies, information about the diversity of wetlands nationally is scarce. In response, we present a national wetland classification system that is based on an ecological approach, from the perspective of wetland scientists, and which builds upon the assumptions underlying the flood pulse concept and hydrogeomorphic approach. Thus, the approach and structure of the Brazilian wetland classification system are used, with geomorphological adjustments made according to Colombia’s topography. The classification is hierarchical, multi-scale, functional, and organized according to four levels (system, macroregion, subsystem, and class), with the wetland diversity of Colombia represented nationally by 89 macrohabitats across marine-coastal, inland, and anthropogenic systems. The primary purpose of this classification is to provide integrated and organized information on the distribution and diversity of Colombian wetlands that will serve as a baseline for transparent environmental policy-making. © 2019, Society of Wetland Scientists.Ítem Coastal erosion and village relocation: a Colombian case study(Elsevier, 2000-01-01) Correa-Arango, Ivan D.; Gonzales, Juan Luis; Universidad EAFIT. Departamento de Geología; Ivan D. Correa-Arango (icorrea@eafit.edu.co); Ciencias del MarBecause of its tectonic setting, the Paci"c coast of Colombia is subject to a variety of geological hazards, including earthquakes, tsunamis and associated phenomena such as regional and local coastal subsidence, #ooding and soil liquefaction. Erosional trends are prevalent along much of the 700 km long, low barrier island's shorelines of the Paci"c littoral and land losses are enhanced by factors such as 30 cm regional sea level rises associated to the occurrence of El Nin8o. Marine erosion is threatening more seashore littoral villages and worsening the already di$cult socioeconomic conditions of most part of the inhabitants. Because of diverse and strong motivations to stay near the sea, the responses of barriers island's inhabitants to marine erosion has consisted in most cases of repetitive in-shore and along-shore directed relocations of villages, rather than de"nitive abandonment of the islands. In the long run, this procedure only has postponed the problem and led to repetitive relocations and economical losses. The recent inland relocation of El Choncho village, on the San Juan River delta, illustrates a di!erent response to marine erosion. Although a new along-shore relocation was physically possible, inhabitants decided to abandon the barrier island and migrate to an interior, ancient beach ridge complex, applying a prudent solution which will be the most appropriate for other threatened villages of the Paci"c littoral. A detailed geomorphologic mapping program must be conducted in order to identify appropriate sites for inland relocation of existing villages on the barriers islands of the Colombian Paci"c coast. ( 2000 Elsevier Science Ltd. All rights reserved.Ítem Coastal erosion and village relocation: A Colombian case study(ELSEVIER SCI LTD, 2000-01-01) Correa, ID; Gonzalez, JL; Universidad EAFIT. Departamento de Geología; Ciencias del MarBecause of its tectonic setting, the Pacific coast of Colombia is subject to a variety of geological hazards, including earthquakes, tsunamis and associated phenomena such as regional and local coastal subsidence, flooding and soil liquefaction. Erosional trends are prevalent along much of the 700 km long, low barrier island's shorelines of the Pacific littoral and land losses are enhanced by factors such as 30 cm regional sea level rises associated to the occurrence of El Nino. Marine erosion is threatening more seashore littoral villages and worsening the already difficult socioeconomic conditions of most part of the inhabitants. Because of diverse and strong motivations to stay near the sea, the responses of barriers island's inhabitants to marine erosion has consisted in most cases of repetitive in-shore and along-shore directed relocations of villages, rather than definitive abandonment of the islands. In the long run, this procedure only has postponed the problem and led to repetitive relocations and economical losses. The recent inland relocation of El Choncho village, on the San Juan River delta, illustrates a different response to marine erosion. Although a new along-shore relocation was physically possible, inhabitants decided to abandon the barrier island and migrate to an interior, ancient beach ridge complex, applying a prudent solution which will be the most appropriate for other threatened villages of the Pacific littoral. A detailed geomorphologic mapping program must be conducted in order to identify appropriate sites for inland relocation of existing villages on the barriers islands of the Colombian Pacific coast. (C) 2000 Elsevier Science Ltd.Because of its tectonic setting, the Pacific coast of Colombia is subject to a variety of geological hazards, including earthquakes, tsunamis and associated phenomena such as regional and local coastal subsidence, flooding and soil liquefaction. Erosional trends are prevalent along much of the 700 km long, low barrier island's shorelines of the Pacific littoral and land losses are enhanced by factors such as 30 cm regional sea level rises associated to the occurrence of El Nino. Marine erosion is threatening more seashore littoral villages and worsening the already difficult socioeconomic conditions of most part of the inhabitants. Because of diverse and strong motivations to stay near the sea, the responses of barriers island's inhabitants to marine erosion has consisted in most cases of repetitive in-shore and along-shore directed relocations of villages, rather than definitive abandonment of the islands. In the long run, this procedure only has postponed the problem and led to repetitive relocations and economical losses. The recent inland relocation of El Choncho village, on the San Juan River delta, illustrates a different response to marine erosion. Although a new along-shore relocation was physically possible, inhabitants decided to abandon the barrier island and migrate to an interior, ancient beach ridge complex, applying a prudent solution which will be the most appropriate for other threatened villages of the Pacific littoral. A detailed geomorphologic mapping program must be conducted in order to identify appropriate sites for inland relocation of existing villages on the barriers islands of the Colombian Pacific coast.Ítem Coherence between infragravity waves and ambient water motions over cape-associated shoals(PERGAMON-ELSEVIER SCIENCE LTD, 2019-01-01) Paniagua-Arroyave J.F.; Valle-Levinson A.; Adams P.N.; Parra S.M.; Universidad EAFIT. Departamento de Geología; Ciencias del MarCross-shelf water motions influence fluxes of nutrients, larvae and sediments, which in turn affect nearshore morphodynamics. Among these motions are infragravity waves, which typically exhibit periodicities from 20 to 200 s, and originate from multiple sources including the superposition of incident wave fields. To examine how infragravity waves co-vary with water motions in an area of complex bathymetry, we analyzed measurements from acoustic Doppler current profilers around cape-associated shoals near Cape Canaveral, on the Florida (USA) Atlantic coast. Observations of water motions and infragravity wave heights at the outer and inner swales of two isolated shoals (Shoal E and Shoal D), located approximately 15 km offshore in ~ 14 m water depth, were subjected to squared coherency and wavelet coherence analyses. Coherences between infragravity wave heights and flow conditions were unsteady, i.e. variable over time, and exhibited differences between outer and inner swales. Subtidal flows (periods > 0.5 days) were sporadically coherent with the total and bound infragravity wave heights at both inner and outer swales. Tidal flows (~ 2 cycles/day) were coherent with the total infragravity wave heights only at outer swale locations. These results indicate that tidal motions may modulate the generation of free (directed both oppositely to and in the direction of short-wave propagation) infragravity waves by short-wave groups shoaling and by refractive trapping at shoals. Subtidal flows, on the other hand, may influence triad interactions that generate infragravity motions. © 2018 Elsevier LtdÍtem El colapso ambiental en el ri´o Pati´a, Colombia: variaciones morfolo´gicas y alteraciones en los ecosistemas de manglar(UNIV CATOLICA DE VALPARAISO, 2014-01-01) Restrepo, Juan Darío; Universidad EAFIT. Departamento de Geología; Ciencias del MarÍtem Combined beach - inner shelf erosion in short and medium term (Maspalomas, Canary Islands)(Faculty of Geology, Martí i Franquès, 2012-12-01) Fontán, A; Alcántara-Carrió, J; Correa-Arango, Ivan D.; Universidad EAFIT. Departamento de Geología; Ivan D. Correa-Arango (icorrea@eafit.edu.co); Ciencias del MarThe analysis of the accurate topo-bathymetric digital elevation model (DEM), the cartography of the submarine sedimentary cover and the monitoring of short (seasonal) and medium-term (2000-2009) morphological changes have permitted depicting the erosional trend in the short and medium-term of the Maspalomas sedimentary system. Short-term analysis showed intense sedimentary fluxes between the beaches and the inner shelf, and sedimentary exchanges with other sectors of the inner shelf, while the steep slope inner shelf fronting La Bajeta cape was identified as a sink area. In the medium-term the sediment budget showed high erosion of the supratidal and intertidal sectors of the beaches due to storm waves in the 2005-2006 winter, followed by accretion over the next four years, but which did not reach the initial sedimentary state. The inner shelf and subtidal sector of the beaches showed negative budgets in the short and medium-term. Interannual variability of the wave and wind regimes determines decadal beach erosion-accretion cycles, while long-term climatic change, evidenced at the study area by a decrease of trade winds and NE wave intensity in 2005, is expected to produce a possible increase of erosion at the El Inglés inner shelf and consequently a decrease in sediment inputs to the El Inglés beach and Maspalomas dune field. Finally, the influence of the geological heritage is depicted by the Fataga gully’s control of the present coastal morphology, and by the island relief control of the wind, waves and current directions in the study area.Ítem Combined beach - inner shelf erosion in short and medium term (Maspalomas, Canary Islands)(UNIV BARCELONA, 2012-12-01) Fontan, A.; Alcantara-Carrio, J.; Correa, I. D.; Universidad EAFIT. Departamento de Geología; Ciencias del MarThe analysis of the accurate topo-bathymetric digital elevation model (DEM), the cartography of the submarine sedimentary cover and the monitoring of short (seasonal) and medium-term (2000-2009) morphological changes have permitted depicting the erosional trend in the short and medium-term of the Maspalomas sedimentary system. Short-term analysis showed intense sedimentary fluxes between the beaches and the inner shelf, and sedimentary exchanges with other sectors of the inner shelf, while the steep slope inner shelf fronting La Bajeta cape was identified as a sink area. In the medium-term the sediment budget showed high erosion of the supratidal and intertidal sectors of the beaches due to storm waves in the 2005-2006 winter, followed by accretion over the next four years, but which did not reach the initial sedimentary state. The inner shelf and subtidal sector of the beaches showed negative budgets in the short and medium-term. Interannual variability of the wave and wind regimes determines decadal beach erosion-accretion cycles, while long-term climatic change, evidenced at the study area by a decrease of trade winds and NE wave intensity in 2005, is expected to produce a possible increase of erosion at the El Inglés inner shelf and consequently a decrease in sediment inputs to the El Inglés beach and Maspalomas dune field. Finally, the influence of the geological heritage is depicted by the Fataga gully's control of the present coastal morphology, and by the island relief control of the wind, waves and current directions in the study area.Ítem Community participation in natural risk prevention: Case histories from Colombia(GEOLOGICAL SOC PUBLISHING HOUSE, 2008-01-01) Hermelin, M.; Bedoya, G.; Universidad EAFIT. Departamento de Geología; Ciencias del MarMore than 75% of Colombia's 42 million people live in urban areas located in the mountains and are exposed to numerous natural hazards: floods, flash floods, landslides, earthquakes and volcanism. The Armero disaster of 1985 triggered the creation of the National System for Disaster Prevention and Relief. National, regional and local committees started to operate across the country, accompanied by education commissions that produced diverse audiovisual materials to help educate people living in these areas. The experiences of working with local committees gained during the last two decades are presented here. Case histories are from cities such as Pereira, Manizales and Medellín, where the local committees are run by people with little or no formal education but who understand that they must participate as a group to prevent or mitigate the effects of natural disasters. The co-operation between technical experts and trained residents represents an outstanding example of good communication and co-operation for urban populations living in dangerous areas. Although many problems have yet to be resolved, these case histories show that this type of organization seems to be more effective than direct intervention from national government agencies. The models of community participation and communication developed and refined here may have application to similar social environments in other countries. © 2008 Geological Society of London.