Hindcast of wind driven wave heights in water reservoirs

Abstract

The paper is focused on the problems of water level motion in water reservoirs. Dimensions of wind driven waves are closely related to the parameters of occurring wind. Due to the complexity of the physical phenomena, most methods for wave prediction are based on semi-empirical relations. The theories for approximation of waves follow two approaches. The first one, called regular waves, is based on mathematical description of water surface. The second one, called irregular waves, results from statistical processing of collected data. The methods have been modified as wind and wave data were accumulated over time, resulting in better predictions. The aim of the present research consists in verification of two selected irregular wave models for characteristic wave height estimation - the first one widely used by U.S. Army Corps of Engineers (USACE) for sea and large inland water bodies conditions and the second one related to the Czech standard specification CSN 75 0255 Calculation of wave effects on hydraulic structures. Characteristic wave height represents one of the most important wave parameters as an input for consequent computational tasks dealing with hydrodynamic events occurring on the point of interaction between water level and shore (wave breaking, wave setup, wave run-up on structures and banks, etc.). Further, the paper discusses relevant statistical techniques for proper exploration of special data of wave motion gained from in situ measurements.