The problem of selecting the appropriate design flood is a constant concern to dam engineering and, in general, in the hydrological practice. Overtopping represents more than 40% of dam failures in the world. The determination of the design flood is based in some cases on the T-year quantile of flood peak, and in other cases considering also the T-year quantile of flood volume. However, flood peak and flood volume have a positive (strong or weak) dependence. To model properly this aspect a bivariate probability distribution is considered using the concept of 2-Copulas, and a bivariate extreme value distribution with generalized extreme value marginals is proposed. The peak-volume pair can then be transformed into the correspondent flood hydrograph, representing the river basin response, through a simple linear model. The hydrological safety of dams is considered checking adequacy of dam spillway. The reservoir behavior is tested using a long synthetic series of flood hydrographs. An application to an existing dam is given.

[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.

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