Multiple reservoirs effect on flood frequency at the catchment scale

Realization of a multiple reservoirs system has huge consequences on the natural hydrological regime of a river catchment. The reduction in intensity and occurrence of the peak discharge represents one of the effects and its evaluation is crucial for risk management purposes. The aim of this work is to understand how the system works and how the peak discharge is influenced by the reservoirs location, dimensions and numbers. The mathematical framework is based on the Instantaneous Unit Hydrograph (IUH) method, and it is referred to the specific case of multiple reservoirs located in series along the main channel. Moreover, the framework is fully linear and it allows to describe the system as sum of multiple contributions, distinguishing those that have a strong influence on the peak discharge. Results are depicted and discussed for a system of two reservoirs, providing a view of the system dynamics. Moreover, results are generalized in order to understand the role of the parameters.