M. Habitat time series analysis to develop flow management criteria in rivers affected by hydropeaking.

Hydropeaking induced by storage hydropower plants can modify the natural flow regime at different time scales, with severe impacts on the biodiversity of the downstream river ecosystems. In this research, a case study on the Noce River (NE Italy) is presented, where habitat simulation models and habitat time series were used to compare restoration scenarios and develop flow management criteria. Habitat time series analyses are based on the assumption that habitat events occurring rarely in nature create stress to aquatic fauna and shape the community. The identification of habitat stressor thresholds (HST) provided a means of quantitatively comparing different flow magnitude scenarios as well as duration and frequency of events. Results indicate that (i) the proposed flow management plan should nullify the rare habitat stress events to support the recovery of existing fish populations and (ii) HST can be used to identify flow release strategies in rivers affected by hydropeaking.