Metodología para gestión de información hidrológica en vías navegables: aplicación a Bolivia

The Hydrometric Network of the Bolivian Navy (RHAB) database lacks the ease of consultation required by a modern administrator for the optimization of the management of hydrological resources. Therefore, we presenteda new methodology, generalizable to any country, to develop a multidisciplinary geographic information system (GIS) on the web. It is easy and intuitive to use and oriented to hydrometric information management for early warning, navigation support,and fluvial and lacustrine transport, and for projects and works involving research, engineering, cartography, fishing, tourism, etc. The geographic database containing the hydrological information is accessed through the internet with a geographical web viewer. Different free distribution software applications have been integrated together with different programming languages. The immediate provision of accurate data also helps in the prevention of flood disaster

Análisis de rendimiento de la cántara de una draga de succión en marcha en función de la granulometría del material transportado

El proceso de sedimentación en la cántara de una draga de succión en marcha es muy complejo pero, a pesar de ello, actualmente existen modelos basados en la aplicación de las distintas teorías experimentales sobre la difusión turbulenta del material en tanques de sedimentación [Camp (1936) o Dobbins (1944)], que pueden ser aplicados con bastante aproximación, como se comprobará en este artículo, siempre que se tengan en cuenta algunas consideraciones. Se han aplicado dichos modelos a una obra de dragado hidráulico, en la que se transportaron 5 tipos de materiales de distinta granulometría. El objetivo era observar los rendimientos totales del proceso de llenado tomando como base los datos obtenidos durante la ejecución de la obra. Para ello se han calculado las velocidades de sedimentación de los distintos materiales transportados en la cántara al objeto de relacionarlas con las dimensiones de la misma para, de esta manera, comparar también los distintos rendimientos correspondientes a cada uno de dichos materiales. Para estos materiales se ha comprobado que los resultados que se consiguen con la aplicación de las ecuaciones de Stokes y Budryck son prácticamente coincidentes cuando se emplea el modelo de Camp, lo cual es lógico dado el tipo de flujo que se produce. También se hace un análisis comparativo entre los valores de las velocidades cuando se consideran como grano individual o bien como una nube de granos. Al objeto de predecir el rendimiento de la cántara de una draga de succión en marcha, se deberían de considerar todos los casos, marcando como límites las velocidades de Stokes y Budryck por un lado y las que correspondan a la ecuación general corregida por el Nº de Reynolds obtenido por cualquiera de estas ecuaciones. Abstract: The sedimentation process in the hopper of a trailing suction hopper dredger is very complex though, in spite of this, models are currently available based on the application of different experimental theories concerning the turbulent diffusion of the material in sedimentation tanks [Camp 1936 or Dobbins (1944)]. These theories, as shown by this article, may be applied with a reasonable degree of accuracy on the condition that these take into account certain considerations. These models have been applied to a dredging project which transported five types of material of different particle size. The objective was to observe the total performance of the filling process on the basis of data obtained during the work. To this end, a calculation has been made of the sedimentation or settling velocity of the different materials transported in the hopper in order to relate these to the sizes of the same and, in this way, compare the different performances of each material. In these materials it has been seen that the results obtained through the application of Stokes and Budryck equations practically coincide when employing the Camp model, this being logical in view of the type of flow produced. A comparative analysis was also made between the velocities when taking the material in the form of an individual grain or as a group of grains. In order to predict the performance of the hopper in an operating trailing suction dredger it is necessary to consider, in all cases, the velocities established by Stokes and Budryck as limit values and to consider those corresponding to the general equation corrected by the Reynolds number obtained by any of these equations

Shipping emissions in the Iberian Peninsula and the impacts on air quality

Marine traffic has been identified as a relevant source of pollutants, which cause known negative effects on air quality. The Iberian Peninsula is a central point in the connection of shipping traffic between the Americas, Africa, and the rest of Europe. To estimate the effects of shipping emissions inland and around the Iberian Peninsula, the EMEP/MSC-W model was run considering and not considering shipping emissions (obtained with STEAM3). Total estimated emissions of CO, CO2, SOx, NOx, and particulate matter (subdivided into elementary carbon - EC, organic carbon - OC, sulfate, and ash) for the study domain in 2015 were respectively 49, 30000, 360, 710, 4.5, 11, 32, and 3.3 kt yr(-1). Shipping emissions increased SO2 and NO2 concentrations, especially near port areas, and also increased the O-3, sulfate, and particulate matter (PM2.5 and PM10) concentrations over the entire Iberian Peninsula coastline (especially in the south coastal region). Shipping emissions were responsible for exceedances of WHO air quality guidelines for PM2.5 in areas far from the coastline, which confirms that shipping emissions can contribute negatively to air quality, both in coastal and inland areas

The Influence of Emissions from Maritime Transport on Air Quality in the Strait of Gibraltar (Spain)

Gaseous and particulate emissions from oceangoing ships have a significant effect on the quality of air in cities. This study estimates mainly the influence of NOx, SOx, and particulate matter (PM2.5) on air quality in the Strait of Gibraltar (Spain) using the authors' own Ship's Energy and Emissions Model (SENEM) and the California Puff air quality model (CALPUFF) in 2017. The Algeciras Bay Industrial Zone recorded the highest levels of pollutants, and the Palmones area was identified as a major hotspot, with mean daily ship-sourced SOx concentrations >215 mu g/m(3), while the highest concentrations of PM10 reached 8.5 mu g/m(3) inside the Strait, and the mean yearly contribution of PM2.5 reached 0.86 mu g/m(3) in the city of Algeciras. The incidence of maritime traffic emissions on the levels of particle emissions, CO, HC, NMVOC, and CO2 reached values of up to 20-25% in all the receivers defined in the study

Calculating a Drop in Carbon Emissions in the Strait of Gibraltar (Spain) from Domestic Shipping Traffic Caused by the COVID-19 Crisis

As a consequence of the COVID-19 pandemic, the Spanish government declared a State of Emergency, and domestic passenger ship traffic was restricted in Spanish ports. This manuscript presents scenarios of emissions from domestic shipping traffic in the seas of the Strait of Gibraltar (Spain) over three months of the COVID-19 pandemic. Emissions were estimated for only 90 days of the pandemic, and two scenarios were studied: emissions while vessels were berthed at the Algeciras Port and emissions as a consequence of the interruption of passenger ship transportation in the Strait of Gibraltar. To this end, the authors' own model was used, which has near zero uncertainties. This model was used for the first time in this study and takes into account both meteorological and sea condition parameters, as well as the efficiency of the propulsion system. The manuscript concentrates on the emissions of greenhouse gases (GHGs), nitrogen oxides (NOx), sulphur oxides (SOx), carbon dioxide (CO2), and particulate matter (PM) from six Ro-Pax ships that ceased to operate. The main finding is that as a consequence of the pandemic, reductions of up to 12% were found in the Strait of Gibraltar in all the pollutants and GHGs when taking into account all international traffic, while the decrease in emissions from domestic traffic only reached 51%

Finding the Optimal Fatty Acid Composition for Biodiesel Improving the Emissions of a One-Cylinder Diesel Generator

Nitrogen oxides (NOx) and particulate matter (PM) currently are the main pollutants emitted by diesel engines. While there is a start in using hybrid and electric cars, ships will still be fueled by mineral oil products. In the quest to achieve zero-pollution and carbon-free shipping, alternative forms of energy carriers must be found to replace the commonly used mineral oil products. One of the possible alternative fuels is biodiesel. This paper explores the optimization of the composition of biodiesel in order to reduce the concentration of particulate matter and NOx in exhaust gases of a one-cylinder diesel generator