1,721,145 research outputs found

    Wave forecasting dependent from bottom roughness: The case of the Marano and Grado Lagoon

    Full text link
    Several forecasting curves have been developed in order to provide a useful estimation of the wind wave field generated on shallow depths. In particular, these equations can be successfully applied in confined and sheltered basins, such as lakes, or even lagoons and semi – enclosed estuarine in coastal environments. The important role of the bottom friction dissipation in the generation process has been deeply recognized, leading to a reformulation of the available curves in terms of the equivalent bed roughness. In the present study, the recent new set of equations is considered and applied to a coastal lagoon. The results in terms of significant wave height and peak period are compared to those derived from a complete numerical model and other previous curves. The performed application corroborates and further validate the forecasting equations

    Two-inlet lagoon systems: Interaction between basins and effects on tidal prisms

    No full text
    In a lagoon basin, the tidal prism is related to the section of its inlet by a simple monomial relationship (LeConte 1905; O’Brien 1931; Jarrett 1976). Although it is not dimensionally correct and there are sophisticated models in two or three dimensions, this relationship is widely used because of its simplicity. Having a simple relationship can be very important, especially when it is necessary to make quick, albeit approximate, evaluations. To maintain this simplicity, the same monomial relationship is often used in multi-inlet lagoons, even if the initial assumptions are not fully met. Another difficulty in applying a monomial relationship to a multi-inlet lagoon is the definition of the area of each basin. In this paper we propose a simple Eulerian, hydrodynamic, one-dimensional approach based on the dynamic response of a non-linear harmonic system and a harmonic analysis of the interaction between two basins in a lagoon system. With such an approach, the definition of the basin surface is overcome simply by working on topographic control basins. The study leads to the definition of a relatively simple relationship for the estimation of tidal prisms, while maintaining the flexibility of a monomial relationship. If the geometrical characteristics and the bottom friction of the inlet channel, the topographic surface of the basins and the amplitude of the tide in the open sea are known, this relationship can be used to estimate the tidal prism in individual basins.The application of this relationship to two-dimensional numerical cases and real multi-inlet lagoons shows good agreement with experimental data
    corecore