Identifying wave and turbulence components in wind-driven shallow basins

Abstract

Wind-induced waves play an important role in shallow lake hydro- and sediment dynamics. That is why field measurements are important for the validation of their estimation methods, especially in shallow waters. In the first part of the present paper a method is introduced to improve the interpretation of the measured data, applicable both for pressure and velocity data. Replacing the turbulence-affected tail of the measured spectrum with a fitted power function causes a considerable 8-10% difference in the derived bulk wave parameters so this procedure is worth to be done. In the second part an appropriate technique to obtain wave features from 3D velocity time series will be described. The applicability of the presented velocity-based estimation method will be proved by the analysis of field measurements. By velocity decomposition used for the reconstruction of wave features one could also analyse the depth-related differences in the turbulence accompanying the wave motion.