Computation of longshore currents and sediment transport

A numerical model for the steady-state profile of the longshore current induced by regular, obliquely incident, breaking waves is presented. The wave parameters must be given at an arbitrary depth. A rapid convergent numerical algorithm is described for the solution of the governing equation. The model is solved using a nonlinear bottom friction law in which the friction coefficients are a function of the bottom roughness which is computed at each point using an empirical formula. The predicted current profiles are combined with some of the known formulae for sediment transport computations.Facultad de Ciencias Naturales y Muse

One-dimensional tidal model of the Ría San Julián, Argentina

Se implementó un modelo numérico unidimensional para sistemas de canales interconectados con el fin de simular la hidrodinámica de la marea de la ría San Julián, Argentina. En posiciones prefijadas dentro del sistema se pronosticaron la altura de la superficie libre y los caudales, utilizando un método implícito en diferencias finitas. Los resultados de la simulación numérica se compararon con mediciones de campo, y se obtuvo una correlación satisfactoria entre marea y corrientes predichas y observadas.A one-dimensional numerical model for a system of interconnected channels was implemented to simulate the tidal hydraulics of the Ría San Julián, Argentina. Free surface displacement and discharge were computed from predetermined locations throughout the system using an implicit, finite-difference technique. The results of the numerical simulation were compared with field measurements, and a satisfactory correlation was obtained between observed and predicted tides and currents.Este documento es bilingüe: español-inglésFacultad de Ciencias Naturales y Muse

Reciclando la salud bucal

La Facultad de Odontología representada por la Asignatura Odontología Preventiva y Social se encuentra realizando un Programa de Trabajos Extramurales en la zona de influencia en Unidades Operativas distribuidas por la Ciudad de La Plata dirigidos por un Docente a cargo y alumnos de 1° a 5º Año desde el Año 1996 hasta la fecha. De los diagnósticos de la Comunidad y en base a los resultados concluimos, que el 68 % de las familias de la zona no tiene, no conoce o no recambia los Cepillos Dentales que son indispensables en Programas de Educación para la Salud Bucal. Por otro lado se detectaron basurales con gran cantidad de botellas de plástico que no son biodegrada- bles (lo cual produce un problema ecológico ambiental) pero si son, reciclables. Esta condición nos llevó a concluir que era necesario, en base a los dos problemas planteados realizar un Proyecto de Extensión que nos permita reciclar los plásticos y obtener a cambio Cepillos de Dientes que nos ayuden a poner en marcha Programas de Educación para la Salud en Escuelas de La Plata y el Gran La Plata.The School of Dentistry represented by the Subject Preventive and Social Dentistry is conducting a Program of Extramural Activities in the area of influence in Operational Units distributed over the City of La Plata led by a teacher in charge and 1st year to 5th year students since 1996 to date. From the diagnostics of the Community and based on the results, we conclude that 68% of the families of the area has not got, does not know or does not change toothbrushes which are essential in Education Programs for Oral Health. On the other hand rubbish dumps containing a lot of plastic bottles that are not biodegradable were detected (which cause an environmental ecological problem), but they do are recyclable. From this condition and based on the two issues raised we arrived to the conclusion that it was necessary to make an Extension Project that allowed us to recycle plastics and get in return Toothbrushes to help us implement Programs for Health Education in Schools from La Plata and Gran La Plata.Facultad de Odontologí

Estudio de las corrientes a lo largo de la Costa en Pinamar, Argentina

Com o objetivo de estudar as correntes longitudinais na orla de Pinamar, Argentina, foi utilizado um ano de observações diárias de alguns parâmetros das ondas e ambientais. Foi efetuada uma análise da regressão linear dos dados para se avaliar a influência desses parâmetros sobre a velocidade da corrente. Foi ainda verificado se outras equações de predição eram aplicáveis a essa área. Também foi pesquisado se a inclusão do vento melhorava as equações de predição. A análise da regressão linear possibilitou apurar que as variáveis mais importantes no cálculo das correntes longitudinais são o ângulo de incidência das ondas, a componente paralela à orla do vento e a altura da onda no ponto de rebentação. Dos resultados obtidos decorre que é possível predizer a velocidade da corrente longitudinal na orla de Pinamar utilizando-se de versões modificadas de expressões já existentes.Facultad de Ciencias Naturales y MuseoComisión de Investigaciones Científicas de la provincia de Buenos Aire

Estimacion de los valores de retorno de la altura de ola en la Provincia de Buenos Aires, Argentina

The wave height recorded at 8 stations along the oceanic coast of the Province of Buenos Aires, Argentina, was analysed to estimate the 50-year return value of wave height at each station. The probability distributions of wave height for the measurements made at Mar de Ajo (1976/85), punta Medanos (northern and southern waveriders, 1981/84), Pinamar (1976/91), Mar del Plata (1968/69), Puerto Quequen (1975/76), Pehuen-Co (1986/88) and El Condor (1988) summer resort were tested with the theoretical distributions of Rayleigh, Weibull and Fisher-Tippett I. Excluding Mar de Ajo and El Condor, the best fit was obtained with the Fisher-Tippett probability density function. The method of Battjes for estimating the return values of wave height was applied and the resulting 50-year return values were 2.80; 6.90; 7.90; 7.20; 7.21; 8.20; 4.30 and 2.84 m for Mar de Ajo, punta Medanos (northern waverider), punta Medanos (southern waverider), Pinamar, Mar del Plata, Puerto Quequen, Pehuen-Co and El Condor, respectively. Lastly, the standard method of extreme values was used to analyse 10 and 16 annual wave height maxima from Mar de Ajo and Pinamar, respectively. The 50-year return values were found to be 2.30 m for Mar de Ajo and 7.20 m for Piramar.Facultad de Ciencias Naturales y Muse