Modeling Hydrodynamics and Sediment Transport in Kremasta Reservoir

The calculation of the sediment yield inside a reservoir is critical for the design and the operation of a dam or a hydroelectric station. More specifically, for the present thesis the estimation of soil loss is carried out using the Revised Universal Soil Loss Equation (RUSLE) and Koutsoyiannis & Tarla (1987) methods by gathering precipitation, geomorphological and topographical data, and maps. Another way to estimate the soil loss of the watershed, is to collect maps from the European Soil Data Centre (ESDAC) in grid form for every factor of the RUSLE equation, and estimate the soil loss using Geographic Information Systems. All these methods result in a mean annual value of soil loss and the use of Vanoni (1975) equation afterwards leads to the computation of the sediment yield. However, the use of flow-sediment load rating curves, based on field measurements, seems to be a more direct and precise method for this purpose. What follows next is the application of a 1D hydrodynamic-sediment transport HEC- RAS model to estimate the bed changes of Kremasta reservoir throughout the years by inputting the computed rating curves, timeseries of inflow and stage data and the initial bathymetry of the reservoir. This study could assist in extracting some meaningful conclusions regarding the exact locations of sediment deposits, the changes in bathymetry and the hydrodynamic characteristics, and understand how the design and operation of the dam and the hydroelectric station is affected by sediment deposits