Human disturbances of shoreline morphodynamics and dune ecosystem at the Puerto Velero spit (Colombian caribbean)

Evolution of present coastal environments is controlled by both natural processes and anthropogenic activities, last one causing global, regional and local disturbances. This study analyze the effects of shortage of sediments from Magdalena River and tourism development in the recent shoreline morphodynamics and dune vegetation structure of the Puerto Velero spit, in the northern Colombian Caribbean coast. Shoreline position, dune vegetation and human occupation were taken from the interpretation of satellite images, aerial photographs and field trips. Three methods were applied to analyze shoreline migration. It allowed to deduce trends of very high erosion for the outer neck and moderate to high erosion for the inner neck, while the northern border and the point of the spit present an erosional trend in the outer and inner. Therefore, the outer neck and iner neck show predominance of an erosional trend, more intense for the outer one, while the northern border and particularly the point of the spit present trends of high and very high accretion. It implicates a present progradation of the spit, but a narrowing of its neck. The shortage of coastal sand due to the construction of a jettie at Magdalena River favored the formation of the spit by the erosion of the extinct Isla Verde barrier island, but currently cause erosion of the neck. Erosion of the outer and inner neck is also due to the impact of local disturbances on the backshore and dune system, mainly a rapid increase of occupation and a large circulation of people and vehicles. Dune vegetation distribution is affected by these disturbance, including the presence of invasive aloctonous Calotropis procera over a large area of the dune field. The natural climatic oscillations, particularly the negative El Niño Southern Oscillation (ENSO) events, also favor the progradation of the spit. The analysis of these disturbances on the present geomorphological and ecological evolution on the spit constitutes an important instrument for coastal management

Estudio financiero y fiscal para la creación del Area Metropolitana de la Cuenca de Tota

133 hojas : ilustraciones color, tablas, cuadros, imágenes, gráficos.ecosistema de vital importancia para la región; es el primer lago del país y el segundo de Latinoamérica y además está situado a una altura por encima de los 3000 msnm (DNP 2014). Alrededor de este, coexisten problemas sociales, ambientales y económicos que no pueden ni han podido ser solucionados desde las iniciativas locales y que por tanto, requieren de la coordinada gestión de los recursos entre los municipios que tienen territorios dentro de la cuenca hidrográfica de Tota. Conseguir crear una entidad administrativa como el Área Metropolitana de La Cuenca de Tota (AMCT) que reúna a los municipios de Sogamoso, Aquitania, Cuítiva y Tota, requiere del esfuerzo de las respectivas administraciones municipales para garantizar los recursos que serán necesarios para la inversión inicial y el funcionamiento en el largo plazo. Los recursos son suficientes. La voluntad de los pobladores como contribuyentes de una sobretasa metropolitana del 2*1000 sobre el impuesto predial, debe conseguirse a través de la capacitación y la realización de otros estudios paralelos al presente. En el escenario planteado en la actual investigación, el proyecto es viable financiera y fiscalmente. Sin embargo enfrenta algunos riesgos, la consecuente solución solo puede depender de la adecuada gestión ya que existe la posibilidad de recurrir a fuentes de financiación alternas que apoyen la sostenibilidad financiera de la organización. Los recursos disponibles para la inversión, se cree, son suficientes para generar iniciativas que socaven el atraso y la contaminación que padece el ecosistema hídrico Cuenca de Tota.The resources are sufficient. The will of residents as contributors of a metropolitan surcharge of 2 * 1000 on the property tax, should be ensured through training and other studies parallel to the present. In the scenario posed in the present investigation, the project is viable financial and tax purposes. However, it faces risks, consistent solution only can depend on proper management because there is the possibility of resorting to alternative funding sources that support the financial sustainability of the Organization. The resources available for investment, it is believed, are sufficient to generate initiatives that undermine the backwardness and pollution that have Tota basin water ecosystemTota Lake located in the department of Boyaca (Colombia), for the region is a vital ecosystem Importance; it is the primer lake country and the second in Latin America and It is located at an altitude above 3000 m (DNP 2014). Around this, coexist however, social problems, environmental and economical that they can’t have not been able to be solved form local initiatives and therefore require coordinated management of resources among the municipalities wich have territories within the drainage basin of Tota. To create an administrative entity as the Metropolitan Area of basin of Tota (AMCT) that brings together the municipalities of Sogamoso, Aquitaine, Cuítiva and Tota, requires the effort of the respective municipal administrations to secure resources that will be necessary for the initial investment and performance in the long term.Bibliografía y webgrafía: hojas 112-115.PregradoContador Públic

Beach litter distribution in Admiralty Bay, King George Island, Antarctica

In the Antarctic Peninsula, most important activities are touristic visits, from the second half of the 20th Century, and scientific investigation linked to 75 research stations. Beach litter content/abundance was investigated at 17 beaches in Admiralty Bay (King George Island, Antarctica) and the type of plastic material was determined by Raman spectroscopy. An average value of 0.16 items m−1 was observed. Wood items consisted of processed wood fragments representing 47.27% of the total. Foam represented 21%, hard plastic pieces 9.68% (consisting of polyvinyl chloride or high density polyethylene), metal 3.37%, rubber fragments 2.81%, foamed plastic pieces 2.66% (composed by polystyrene), the rest of categories representing less than 2% of the total. Wood debris and metal are essentially remnant objects of ancient whaling activities and research expeditions, polyurethane and expanded polystyrene materials have different origins and hard plastic, rubber, paper/cardboard and paint fragments seem mostly linked to present research activities

Mangrove Forests Evolution and Threats in the Caribbean Sea of Colombia

Colombia has approximately 379,954 hectares of mangrove forests distributed along the Pacific Ocean and the Caribbean Sea coasts. Such forests are experiencing the highest annual rate of loss recorded in South America and, in the last three decades, approximately 40,000 hectares have been greatly affected by natural and, especially, human impacts. This study determined, by the use of Landsat multispectral satellite images, the evolution of three mangrove forests located in the Colombian Caribbean Sea: Malloquin, Totumo, and La Virgen swamps. Mangrove forest at Mallorquin Swamp recorded a loss of 15 ha in the period of 1985-2018, associated with alterations in forest hydrology, illegal logging, urban growth, and coastal erosion. Totumo Swamp lost 301 ha in the period 1985-2018 associated with changes in hydrological conditions, illegal logging, and increased agricultural and livestock uses. La Virgen Swamp presented a loss of 31 ha in the period of 2013-2018 that was linked to the construction of a roadway, alterations of hydrological conditions, illegal logging, and soil urbanization, mainly for tourist purposes. Although Colombian legislation has made efforts to protect mangrove ecosystems, human activities are the main cause of mangrove degradation, and thus it is mandatory for the local population to understand the value of the ecosystem services provided by mangroves

Magnitude and causes of beach accretion on the eastern margin of the Tayrona National Natural Park (Colombian Caribbean)

Beaches on the eastern margin of Tayrona National Natural Park experienced stability and even accretion over the last decade, in contrast to general erosion along the Colombian Caribbean coast. The objective of this study is to characterize shoreline change and analyze the factors contributing to the accretionary trend. Orthorectified satellite images, combined with topography from both drone images and RTK-DGPS measurements, were used to map successive shorelines from 2002-2008. Net shoreline movement and shoreline migration rates revealed these beaches had an accretionary trend, with the exception of Piscina Beach that eroded during the time period. The maintenance of natural inputs of sediment from local rivers, redistributed by littoral drift with sediment bypassing across the small headlands limiting the beaches, the resilience of the beaches to the impact of hurricanes and low human pressure allows for a positive sedimentary budget for the beaches. Piscinas Beach is the most cut off from fluvial sediment input, and despite it has a coral reef barrier, its dissipative profile indicate that it is the most exposed to wave impact

Marine litter arrived: Distribution and potential sources on an unpopulated atoll in the Seaflower Biosphere Reserve, Caribbean Sea

The Albuquerque atoll was studied as a representative natural laboratory to explore the role of sea-based sources of marine litter. This work aimed to identify the small-scale spatial distribution of marine litter (i.e., plastic, glass, paper, and others) as well as to explore the connectivity among the atoll habitats (sand beach, water surface, and reef) to give insights of potential sources of marine litter (>5 cm), mainly plastics. Marine litter was dominated by plastic items, as expected, with an average value of 0.5 items/m2. Large microplastics (1–5 mm) were also sampled on beaches with an average value of 90 particles/m2. In the atoll inner lagoon, marine litter was also composed by plastic, mainly fragments (average 0.059 items/m3). The predominance of plastic fragments on both the sea surface and beaches of the atoll makes inferences on sources limited. However, o fishing activities and sea-based sources might be relevant since local sources are very limited

Assessment of heavy metals pollution (Hg, Cr, Cd, Ni) in the sediments of Mallorquin Lagoon - Barranquilla, Colombia

The levels of four toxic heavy metals (Hg; Cr; Cd; Ni) present in 17 sediment samples of the Mallorquin lagoon –Barranquilla (N Colombia) were investigated in order to assessing the potential risks of accumulation. The sample preparation was performed by acid microwave digestion with “Multiwave” system, carried out using GFAAS. High contamination levels, especially for Hg, Cr and Cd, were detected in samples M4 (0.199; 96.71; 1.212 μg.g-1), M5 (0.153; 100.38; 1.076 μg.g-1), M6 (0.140; 97.74; 1.850 μg.g-1), M8 (0.122; 90.41; 1.023 μg.g-1) y M9 (0.143; 100.92; 1.086 μg.g-1). The results reflect the anthropogenic activities, as accelerated urbanization without planning, deposit for solid waste, contribution from the Magdalena River, affected by illegal mining. In addition, the Leon stream drains the entire metropolitan area by pouring into the lagoon a great amount of untreated sewage every day. The concentrations found in most samples of the Hg, Cr and Cd elements are above the internationally recommended limits. The levels of metals found are alarming, considering that this lagoon represents a source of food for the population of its surroundings

Real time monitoring system for the detection of saline wedge in the Magdalena River – Colombia

This article aims to socialize the results of the development and implementation of a system based on IOT for aquifers, with its application in the estuary of the Rio Magdalena in Colombia. The SISME software supports the identification processes of different factors that can influence the appearance of the saline wedge in the navigable channel of the river. These aspects bring about the improvement of maritime safety and, in turn, allow us to know different aspects related to behavior through continuous sensing of the river. This article shows both the characterization of this river as well as studies related to it and the location of the sensors and description of the software developed

Internet of things applied to aquifer monitoring systems: a survey

The interaction between the oceanic and continental basins has been of general interest among the scientific community of multiple disciplines, from the physical perspective of how the interaction of fresh and salt waters mutually modulate their hydrodynamic behavior, and how this in turn determines the transport of sediments, nutrients and other tracers, in addition to inducing changes in the morphodynamics of the river and / or coastal-oceanic zone. Due to the importance of technology for the prevention of different environmental phenomena, this article aims to show the systematic review of the literature about different applications that allow software and hardware interaction to support decision making in the sense of aquifers

Multilayer Perceptron applied to the IOT systems for identification of saline wedge in the Magdalena estuary - Colombia

Maritime safety has become a relevant aspect in logistics processes using rivers. In Colombia, specifically in the Caribbean Region, there is the Magdalena River, a body of water that broadly borders the Colombian territory and is a tributary of various economic and public health activities. At its mouth, this river interacts with the sea directly, which generates a phenomenon called saline wedge, which is directly related to the sediments that must be continuously extracted and which threatens the proper functioning of the port from the city of Barranquilla, Colombia. Through this research, a network of sensors located in strategic places at the mouth of this river was generated, which allows predicting the behavior of the salt wedge. Using artificial neural networks, more specifically, the Multilayer Perceptron algorithm, it was possible to analyze the results of the implementation in light of the indicators or quality metrics, generating a highly reliable scenario that can be replicated in other sections of the river and in other aquifers