El desarrollo del carso epigenético en el modelo evolutivo de la región central de la Sierra de Los Órganos

La edad del carso epigenético para la Sierra de los Órganos, queda definida a partir del momento en que quedan destapadas las secuencias carbonatadas y comienzan a sufrir los procesos denudativos al final del Oligoceno y principios del Mioceno (aproximadamente unos 25 Ma). Aunque las formas cársicas en la región central de la Sierra de los Órganos surgieron en momentos diferentes, todas coexisten en el paisaje de hoy. Mientras, de forma general, la región ascendía lentamente y oscilaba el nivel del mar, descendía el nivel de base regional de erosión dando lugar a superficies de nivelación disecadas por numerosas dolinas. En este momento, las corrientes superficiales desaparecen para convertirse en corrientes subterráneas, que han labrado una extensa red de galerías. Interpretación de imágenes de satélites, fotos aéreas, levantamiento geológico, mediciones de morfoestructuras y el análisis estadístico multivariado, fueron los métodos utilizados para el establecimiento del modelo del carso epigenético en la región. El procesamiento de imágenes y fotos aéreas, permitió el contorneo de las formas cársicas que afloran en el área, así como la cartografía de estructuras tectónicas. El levantamiento geológico precisó los límites y características de los diferentes complejos rocosos, mientras que las mediciones de morfoestructuras y el análisis estadístico multivariado posibilitaron el estudio de la relación entre cotas de bocas de cuevas y fondo de dolinas, así como la relación de las cotas del relieve con su área, lo que determinó los niveles de base de erosión del carso epigenético de la región, para actualizar el modelo evolutivo de la geología en la zona. Se establecieron nueve niveles de base de erosión, de los cuales seis fueron fechados utilizando como base los resultados obtenidos para los niveles de cuevas emisivas de la cuenca del río Cuyaguateje (Molerio et al., 1999). A partir de estos resultados, se confeccionaron los mapas de niveles de base de erosión para el territorio y los respectivos mapas de pisos altitudinales, geológicos y de formas del carso epigenético, correspondientes a cada nivel de base determinado

Inventario de fenómenos gravitacionales en el Occidente de Cuba

The present paper has as objective to elaborate an inventory of gravitational phenomenon’s in the most western area in Cuba that offers a more integral vision of the susceptibility from the territory to the occurrence of this phenomenon. For it, they were carried out two inventories of gravitational phenomenon’s, one associated to the road through a field work and the other based in the photograph interpretation of satelital images obtained by the googgle earth.  As a result, an inventory was obtained where they register the slides of the area and its more particular characteristics are described, elements that were not shown in an integral way until the moment, what facilitates, to interpret the results better and to determine the variables that exercise bigger influence in the occurrence of these phenomenon’s, is also shown, the most susceptible sectors to the occurrence of these. For better to graph the results three maps are elaborated, two that show the density of phenomenon’s for Popular Council and the third associate the populational density with the areas where they register the slides.El presente artículo tiene como objetivo elaborar un inventario de deslizamientos en la zona más occidental de Cuba, que brinde una visión más integral de la susceptibilidad del territorio a la ocurrencia de dichos fenómenos gravitacionales. Para ello, se realizaron dos inventarios de fenómenos gravitacionales, uno asociado a las redes viales a través de trabajos de campo y el otro a partir de la fotointerpretación de imágenes satelitales obtenidas del Googgle Earth. Como resultado, se obtuvo un inventario donde se registran los deslizamientos de la zona y se describen sus características más particulares, elementos que hasta el momento no se mostraban de manera integral, lo que posibilita, interpretar mejor los resultados y determinar las variables que ejercen mayor influencia en la ocurrencia de estos fenómenos, se muestra además, los sectores más susceptibles a la ocurrencia de estos. Para graficar mejor los resultados se elaboran tres mapas, dos que muestran la densidad de fenómenos por Consejos Populares y el tercero asocia la densidad poblacional con las zonas donde se registran los deslizamientos. Como conclusión fundamental y a partir de los resultados de la investigación se pudo constatar que los inventarios de deslizamientos representan una herramienta útil como punto de partida para el estudio de riesgo y susceptibilidad de un territorio

Inventory of gravitational phenomena in the West of Cuba

The present paper has as objective to elaborate an inventory of gravitational phenomenon’s in the most western area in Cuba that offers a more integral vision of the susceptibility from the territory to the occurrence of this phenomenon. For it, they were carried out two inventories of gravitational phenomenon’s, one associated to the road through a field work and the other based in the photograph interpretation of satelital images obtained by the google earth. As a result, an inventory was obtained where they register the slides of the area and its more particular characteristics are described, elements that were not shown in an integral way until the moment, what facilitates, to interpret the results better and to determine the variables that exercise bigger influence in the occurrence of these phenomenon’s, is also shown, the most susceptible sectors to the occurrence of these. For better to graph the results three maps are elaborated, two that show the density of phenomenon’s for Popular Council and the third associate the populational density with the areas where they register the slides

Inventory of gravitational phenomena in the West of Cuba

The present paper has as objective to elaborate an inventory of gravitational phenomenon’s in the most western area in Cuba that offers a more integral vision of the susceptibility from the territory to the occurrence of this phenomenon. For it, they were carried out two inventories of gravitational phenomenon’s, one associated to the road through a field work and the other based in the photograph interpretation of satelital images obtained by the googgle earth.  As a result, an inventory was obtained where they register the slides of the area and its more particular characteristics are described, elements that were not shown in an integral way until the moment, what facilitates, to interpret the results better and to determine the variables that exercise bigger influence in the occurrence of these phenomenon’s, is also shown, the most susceptible sectors to the occurrence of these. For better to graph the results three maps are elaborated, two that show the density of phenomenon’s for Popular Council and the third associate the populational density with the areas where they register the slides

Structural and lithological conditioning of the large karst systems of the Sierra de los Órganos, Pinar del Rio, Cuba

El karst, fenómeno extremadamente complejo, responde a un conjunto de variables que condicionan su génesis y desarrollo. Entre estas condicionantes juegan un importante papel las características litológicas y tectónicas de un territorio. En Cuba, los territorios kársticos ocupan aproximadamente el 65% de la superficie, la Sierra de los Órganos, macizo montañoso que forma parte de la Cordillera de Guaniguanico, en el distrito geográfico pinareño, alberga varios de los mayores sistemas kársticos del archipiélago cubano. Con el objetivo de demostrar la relación entre el desarrollo espacial y morfológico de los sistemas kársticos subterráneos con la estructura geológica del territorio, partiendo de la premisa del control litoestratigráfico y tectónico casi absoluto del desarrollo espacial, morfológico y morfométrico de las redes cavernarias, se desarrollaron una serie de trabajos de medición de de elementos estructurales y morfológicos, que permitieron arribar a la conclusión de que en la Sierra de los Órganos los procesos kársticos se desarrollan principalmente en calizas masivas, relativamente homogéneas, de espesores considerables, poco porosas y muy fracturadas. Estas formas kársticas están condicionadas por la existencia de uno o más planos de agrietamiento con una orientación general NE, NO, siendo las zonas de intercepción de planos de grietas los lugares donde existen mayores volúmenes de cavidades kársticas. The karst, a complex phenomenon, is governed by a number of variables which dictate its genesis and evolution. Among these variables tectonic settings and lithology play the main role. In Cuba, approximately 65% of the territory is occupied by karst. The Sierra de los Órganos, part of Cordillera de Guaniguanico, has some of the largest karstic systems in the country. With the aim of demonstrating the relationship between the spatial and morphological development of the underground karstic systems and the geological structure and lithology of the area, several structural and morphological measurements and field observations have been made. These measurements and observations allowing us to conclude that the karstic processes take place mainly in massive, relatively homogeneous and very thick limestone in the Sierra de los Órganos. Moreover, these rocks are characterized by both low porosity and a high degree of fracturing. These karstic forms are also conditioned by the existence of various fracturing systems with general NE-SW and NW-SE orientations. Interception of these fracturing systems provides, as expected, areas with the largest volumes of karstic cavities

Coastal Morphodynamics at Playa Bailén, Southwestern Cuba, 2003-2013

En la actualidad, el análisis de los cambios morfodinámicos de las costas constituye una de las direcciones ambientales e ingenieriles de mayor significado para su planeación y su desarrollo sostenible, así como para la preservación y la protección de sus recursos naturales. Se presentan las tendencias morfodinámicas de la playa Bailén, localizada en la costa suroccidental de Cuba, entre los años 2003 y 2013. Se aplicaron mediciones topográficas del perfil transversal de playa y de la posición de la línea de costa en 15 estaciones de observación, a lo largo de 2 140 m de playa, en los años 2007, 2010 y 2013, comparadas con la posición del año 2003. Los volúmenes de arena acrecionada o erosionada en el período 2003-2007 fueron estimados después de los impactos del huracán Iván del año 2004. Finalmente, se realizaron ensayos granulométricos para establecer las tendencias espacio-temporales en el comportamiento del diámetro promedio de los granos de arena. Para el sector norte de la playa, la tasa máxima de retroceso fue de -2.0 m/año y los análisis granulométricos de las arenas demostraron enriquecimiento en su fracción gruesa. Ambos procesos reflejan la influencia directa de la inadecuada ubicación de las construcciones civiles en la porción frontal de las dunas y en la berma. Por otra parte, en el sector sur el valor máximo de acreción fue de +8.0 m/año y el promedio alcanzó +2.3 m/año. Durante los diez años analizados se observa un bajo nivel de resiliencia en la recuperación de la playa. Due to their geological nature, beaches are susceptible to changes over a relatively short period of time. Composed mainly of recently formed rocks, the scarcely consolidated structure of the substrate makes beaches vulnerable to the action of waves, tides, currents, wind, changes in sea level and human activity. Beach dynamics is marked by different degrees of fragility. In tropical regions, especially in the Caribbean, extreme hydro-meteorological phenomena such as hurricanes and cold fronts associated with extra-tropical storms significantly accelerate the erosion and accretion processes along the coast. The geographical location of the Cuban archipelago, at the margins of the Tropic of Cancer (its northernmost latitude is 27°17’ N), makes it susceptible to the combined action of hurricanes (between June and November) and cold fronts (between November and March). This very fact makes the study of coastal morphodynamic changes a subject of the utmost importance in sustainable-development projects and environmental planning, including the preservation of coastal natural resources. In Cuba, several authors have reported a coastal retreat of 1 to 3 m per year in western beaches, as well as an average loss of sand of about 50 000 m3 per year in the famous Varadero beach. The latter case is mainly due to the extraction of sand from the underwater platform between 1968 and 1978 for construction purposes. This paper addresses the morphodynamic processes taking place at Bailén beach, on the southwestern Cuban coast, as observed during a 10-year period, from 2003 to 2013. Transversal topographic measurements were taken at the beachfront and coastline at 15 observation stations along 2 140 m of beach in 2007, 2010 and 2013. These measurements were then compared to the data available for 2003. Estimated volumes of accreted and eroded sand for the period 2003-2007 indicate remarkable changes in beach morphology and evidence the vulnerability of coastal systems to extreme events, such as those unleashed by hurricane Ivan in 2004. The most important morphological changes observed included an increase of 0.20 to 0.50 m in dune height in some cases, and a decrease in others in the order of 0.15 to 0.40 m. Finally, granulometric tests were conducted to establish the spatial and temporal variations in the diameter of sand grains. To the north side of the beach, the maximum recession rate was 2.0 m per year, and sand grains were larger. Both measurements are indicative of the impact of buildings constructed at the front side of dunes and the beach berm on beach morphology. In the southern sector, on the other hand, the maximum accretion reached 8.0 m per year, whereas the average value was 2.3 m per year. During the 10 years of analysis, beach recovery has been characterized by a low resilience to the impact of hurricanes and other meteorological events. There is a clear spatial correlation between the inadequate location of buildings less than 30 meters from the shore on dunes and berms, where beach dynamics is most intense, and the development of intensive erosive processes, as observed in the northern sector of Bailén beach. The slow recovery of the initial coastline position translates into a steady increase in the average diameter of sediments. The low level of resilience in these beach stretches becomes even more evident when hydro-meteorological events occur. For beach recovery projects through local sand repositioning to be successful, the beachfront must be closely monitored, recording measurements of both sediment dynamics and the effects of wind and water on a transversal profile. Also, to ensure an effective regeneration of this natural resource, an average volume of sand per linear meter of beach must be established. Finally, the demolition of old buildings located at the berm and the front side of dunes, and the prohibition of further construction in these sites, should contribute to restore the morphodynamic balance of this beach and increase the quality of tourism services

Caracterización geológica y geomorfológica de la península de Guanahacabibes, Cuba

El artículo expone los principales rasgos geológicos y geomorfológicos de la península de Guanahacabibes, llanura cársica desarrollada sobre rocas carbonatadas pliocénicas y cuaternarias y territorio considerado reserva de la biosfera. Su rasgo morfológico principal es el predominio de amplios campos de lapiez desnudo o parcialmente cubierto, sin drenaje superficial, asociados con casimbas pequeñas colmatadas, cavernas de origen freático y dolinas de disolución y desplome, con un amplio control litológico y tectónico. A la rica gama de procesos cársicos presentes en la península se vincula, un universo biótico muy singular, complejo y altamente vulnerable, desarrollado de forma armónica durante miles de años

Coastal Morphodynamics at Playa Bailén, Southwestern Cuba, 2003-2013

Due to their geological nature, beaches are susceptible to changes over a relatively short period of time. Composed mainly of recently formed rocks, the scarcely consolidated structure of the substrate makes beaches vulnerable to the action of waves, tides, currents, wind, changes in sea level and human activity. Beach dynamics is marked by different degrees of fragility. In tropical regions, especially in the Caribbean, extreme hydro-meteorological phenomena such as hurricanes and cold fronts associated with extra-tropical storms significantly accelerate the erosion and accretion processes along the coast. The geographical location of the Cuban archipelago, at the margins of the Tropic of Cancer (its northernmost latitude is 27°17’ N), makes it susceptible to the combined action of hurricanes (between June and November) and cold fronts (between November and March). This very fact makes the study of coastal morphodynamic changes a subject of the utmost importance in sustainable-development projects and environmental planning, including the preservation of coastal natural resources. In Cuba, several authors have reported a coastal retreat of 1 to 3 m per year in western beaches, as well as an average loss of sand of about 50 000 m3 per year in the famous Varadero beach. The latter case is mainly due to the extraction of sand from the underwater platform between 1968 and 1978 for construction purposes. This paper addresses the morphodynamic processes taking place at Bailén beach, on the southwestern Cuban coast, as observed during a 10-year period, from 2003 to 2013. Transversal topographic measurements were taken at the beachfront and coastline at 15 observation stations along 2 140 m of beach in 2007, 2010 and 2013. These measurements were then compared to the data available for 2003. Estimated volumes of accreted and eroded sand for the period 2003-2007 indicate remarkable changes in beach morphology and evidence the vulnerability of coastal systems to extreme events, such as those unleashed by hurricane Ivan in 2004. The most important morphological changes observed included an increase of 0.20 to 0.50 m in dune height in some cases, and a decrease in others in the order of 0.15 to 0.40 m. Finally, granulometric tests were conducted to establish the spatial and temporal variations in the diameter of sand grains. To the north side of the beach, the maximum recession rate was 2.0 m per year, and sand grains were larger. Both measurements are indicative of the impact of buildings constructed at the front side of dunes and the beach berm on beach morphology. In the southern sector, on the other hand, the maximum accretion reached 8.0 m per year, whereas the average value was 2.3 m per year. During the 10 years of analysis, beach recovery has been characterized by a low resilience to the impact of hurricanes and other meteorological events. There is a clear spatial correlation between the inadequate location of buildings less than 30 meters from the shore on dunes and berms, where beach dynamics is most intense, and the development of intensive erosive processes, as observed in the northern sector of Bailén beach. The slow recovery of the initial coastline position translates into a steady increase in the average diameter of sediments. The low level of resilience in these beach stretches becomes even more evident when hydro-meteorological events occur. For beach recovery projects through local sand repositioning to be successful, the beachfront must be closely monitored, recording measurements of both sediment dynamics and the effects of wind and water on a transversal profile. Also, to ensure an effective regeneration of this natural resource, an average volume of sand per linear meter of beach must be established. Finally, the demolition of old buildings located at the berm and the front side of dunes, and the prohibition of further construction in these sites, should contribute to restore the morphodynamic balance of this beach and increase the quality of tourism services

Morfodinámica costera en la playa Bailén, costa sur del occidente de Cuba, entre los años 2003-2013

En la actualidad, el análisis de los cambios morfodinámicos de las costas constituye una de las direcciones ambientales e ingenieriles de mayor significado para su planeación y su desarrollo sostenible, así como para la preservación y la protección de sus recursos naturales. Se presentan las tendencias morfodinámicas de la playa Bailén, localizada en la costa suroccidental de Cuba, entre los años 2003 y 2013. Se aplicaron mediciones topográficas del perfil transversal de playa y de la posición de la línea de costa en 15 estaciones de observación, a lo largo de 2 140 m de playa, en los años 2007, 2010 y 2013, comparadas con la posición del año 2003. Los volúmenes de arena acrecionada o erosionada en el período 2003-2007 fueron estimados después de los impactos del huracán Iván del año 2004..

Morfodinámica costera en la playa Bailén, costa sur del occidente de Cuba, entre los años 2003-2013

En la actualidad, el análisis de los cambios morfodinámicos de las costas constituye una de las direcciones ambientales e ingenieriles de mayor significado para su planeación y su desarrollo sostenible, así como para la preservación y la protección de sus recursos naturales. Se presentan las tendencias morfodinámicas de la playa Bailén, localizada en la costa suroccidental de Cuba, entre los años 2003 y 2013. Se aplicaron mediciones topográficas del perfil transversal de playa y de la posición de la línea de costa en 15 estaciones de observación, a lo largo de 2 140 m de playa, en los años 2007, 2010 y 2013, comparadas con la posición del año 2003. Los volúmenes de arena acrecionada o erosionada en el período 2003-2007 fueron estimados después de los impactos del huracán Iván del año 2004..