Author(s): Stefano Cipollini; Aldo Fiori; Elena Volpi

Linked Author(s): Stefano Cipollini, Aldo Fiori

Keywords: Reservoir; Flood frequency; Catchment scale; Instantaneous Unit Hydrograph

Abstract: Quantifying the effects of human activity on flooding is of paramount importance for risk estimation, land planning and to understand hydrologic change, more specifically to disentangle the role of climate from that played by local human interventions. We focus here on the multiple reservoirs effects on the occurrence of floods at the catchment scale; indeed, the presence of reservoirs generally produces an attenuation of flood peaks downstream thanks to their storage capacity (that reserved for flood control). To quantify the impact of one or more unregulated reservoirs on peak flood quantiles at the catchment outlet we present here a simple modeling framework. The framework, which is based on a parsimonious Instantaneous Unit Hydrograph (IUH) method, explicitly accounts for cause-effect mechanisms as in hydrologic-hydraulic simulation, while it keeps simplicity and applicability to many sites, that are the advantages of the data-based approaches. Specifically, the framework consider the reservoirs located in series along the main channel. Furthermore, thanks to some common simplifying assumptions, an approximate analytical solution of the catchment response is provided, useful to easily quantify the reservoir effect at the regional scale and to evaluate how the spatial distribution of the reservoirs affect flood occurrence.

DOI: https://doi.org/10.3850/IAHR-39WC2521711920221284

Year: 2022