heal.abstract |
Sediment discharge measurements in streams are quite rare even in technologically advanced countries, whilst comprehensive physically based models are generally unable to reliably estimate sediment yield of large-scale hydrological basins. A more realistic and reliable alternative method for sediment yield estimation, suitable for watersheds with a dam at the outlet, is the hydrographic surveying of the reservoir's invert and comparison with the one prior to the dam construction resulting to the computation of sediment deposits' volume and mass. This method has been applied to the Acheloos River basin with the hydrographic surveying of Kremasta, a large reservoir with net storage capacity exceeding 3 cubic kilometers. The sediment yield has been estimated not only for the total watershed but also for each of the three tributaries (Acheloos R., Agrafiotis R. and Megdobas R.). Besides, the soil erosion of the watershed has been estimated using an implementation of the Universal Soil Loss Equation on a geographical information system. The sediment delivery ratios have been finally computed combining the sediment yield and soil erosion estimates. |
en |