Suspended sediment transport and deposition in sediment-replenished artificial floods in Mediterranean rivers

Abstract

Dams and impoundments constructed in rivers produce changes in their hydrological and sediment transport regimes, regulate their flows and reduce the supply of sediments downstream. Artificially inducing floods from reservoirs in conjunction with sediment-replenishment strategies is currently being employed to enhance sediment supply to river catchment areas. In this study, sediment-replenished artificial floods are compared to their non-sediment replenishment counterparts. The hysteretic loops between suspended sediment concentration and water flow present low normalized hysteresis indices (close to zero) in the sediment-replenished artificial flood events. In the current work, sediment-replenishment produced a balanced suspended sediment transport in contrast to the without sediment-replenishment cases. The normalized hysteresis indices varied between the different particle sizes studied and the same water flow, indicating that different types of particles are transported differently despite being in the same water flow. Furthermore, both the suspended sediment transport and the sedimentation rate of particles during the flood events was greater for the sediment replenishment cases than for the non-sediment-replenishment cases. All things considered, sediment-replenished artificial flooding provides a successful management strategy for a more balanced suspended sediment transport that could be used as a river restoration practice