Observation and Simulation of Surface Waves in Two Water Supply Reservoirs

Abstract

Observations and model predictions of progressive surface waves were made for Cannonsville and Schoharie Reservoirs, located in southeastern New York State. These reservoirs are deep with steep bottom slopes and relatively small fetch. The Donelan/Great Lakes Environmental Research Lab model, a parametric second-generation wave model was applied to these reservoirs assuming deep water throughout the domain. This assumption was based on the relatively small waves and steep bottom slopes, resulting in a very narrow region of wave interaction with the bottom along a lee shore. Previous applications of this model have been for water bodies with larger fetch. Observations of wave characteristics were made near the shoreline at two sites in Cannonsville and one site in Schoharie using submerged pressure sensors, from which the height of larger waves was determined. Model hindcasts were made for the observation periods with model inputs being wind speed and direction and water surface elevation. The model performed well in simulating significant wave height determined from observations. Some implications of the use of wave model simulations to predict sediment resuspension in these and other deep lakes and reservoirs are discussed.