[1] Subaerial landslides falling into reservoirs or open seas generate impulsive water waves, that are usually referred to as a class of tsunami waves. It is important to study landslide-generated waves occurring both in closed water basins, where the waves interact with the shorelines and eventually the dam, and in open seas, where the generated waves can travel and deliver devastating damages hundreds of kilometers away. In order to gain insight on subaerial landslide generated waves, the Italian National Dam Office recently funded an experimental and numerical research program geared to better understand and forecast tsunamis waves. This paper introduces the experimental work which has been carried out in order to define empirical formulations able to forecast the principal features of the generated waves in a three-dimensional water body, as a function of the landslide movement. Wave types observed during the experiments are here characterized using a wavelet analysis approach; new forecasting formulations (named RID formulas) are defined on the basis of the experimental study and tested using an artificial neural network model. Results are finally compared to those presented in past experimental studies.Citation: Panizzo, A., P. De Girolamo, and A. Petaccia (2005), Forecasting impulse waves generated by subaerial landslides,

Abstract. The empirical formulations to forecast landslide generated water waves, recently defined in the framework of a research program funded by the Italian National Dam Office RID (Registro Italiano Dighe), are here used to study three real cases of subaerial landslides which fell down italian artificial reservoirs. It is well known that impulse water waves generated by landslides constitute a very dangerous menace for human communities living in the shoreline of the artificial basin or downstream the dam. In 1963, the menace became tragedy, when a 270 millions m 3 landslide fell down the Vajont reservoir (Italy), generated an impulse wave which destroyed the city of Longarone, and killed 2000 people.The paper is aimed at presenting the very satisfactorily reproduction of the events at hand by using forecasting formulations.

[1] This paper presents new physical model experiments on tsunamis generated by landslides at the coast of a conical island. The experiments have been carried out in a large wave tank; the radius of the island coastline and the falling height of the landslide have been varied during the experimental campaign. The landslide is reproduced by a solid body shaped as a half of an ellipsoid. Tsunami runup is measured using special wave gauges; a detailed analysis of the runup along the coastline is presented, with special attention to the role of each wave in the packet and to the evolution of the envelope of the first group of waves.

No abstract

The present work introduces a numerical representation of the rheological non Newtonian Bingham model by means of the Smoothed Particle Hydrodynamics (SPH) approach. The model is first re-written using the SPH formalism. Then, it is tested using an annular viscometer test case. Finally, the generation of tsunami waves due to underwater landslide is faced, considering the experimental work of Rzadkiewicz et al. (1997). The implemented rheological SPH model is used to simulate the landslide deformation, and its interaction with water, thus simulating also the generation and propagation of surface tsunami waves. RÉSUMÉLe travail présenté ici introduit une représentation numérique du modèle rhéologique non newtonien de Bingham au moyen de l'approche SPH (Smoothed Particle Hydrodynamics). Le modèle est d'abord réécrit en utilisant le formalisme SPH. Puis, il est testé sur un cas de viscomètre annulaire. Finalement, la génération des tsunamis dus à un éboulement sous-marin est mise en oeuvre, en considérant le travail expérimental de Rzadkiewicz et al. (1997). Le modèle rhéologique SPH implémenté est utilisé pour simuler le glissement de terrain, et son interaction avec l'eau, simulant de ce fait également la génération et la propagation du tsunami en surface.

No abstract

This paper deals with a two-dimensional numerical model based on the smoothed particle hydrodynamics (SPH) technique for the evaluation of the concentration field of pollutants in water. A SPH model is formulated to solve the fickian diffusion equation applied to pollutants with the same density as the water. A lagrangian SPH formalism of the advective diffusion equation is also developed for pollutant-water, taking into account the effects of molecular diffusion and natural advection induced by differences between the fluid densities. These equations are coupled with the fluid mechanics equations. Attention is paid to the numerical aspects involved in the solution procedure and to the optimization of the model parameters. Environmental engineering problems concerning diffusion and natural advection phenomena occur in the presence of a pollutant in still water. Numerical tests referring to a strip and a bubble of contaminant in a water tank with different initial concentration laws have been carried out. The results obtained by the proposed SPH models are compared with other available SPH formulations, showing an overall better agreement with standard analytical solutions in terms of spatial evolution of the concentration values. Capabilities and limits of the proposed SPH models to simulate advective diffusion phenomena for a wide range of density ratios are discussed.

No abstract