Journal of Sedimentary Research, 2018, v. 88, 1190–1204 Research Article DOI: http://dx.doi.org/10.2110/jsr.2018.61 RIVER MORPHODYNAMIC EVOLUTION UNDER DAM-INDUCED BACKWATER: AN EXAMPLE FROM THE PO RIVER (ITALY) VITTORIO MASELLI,1,2 CLAUDIO PELLEGRINI,2 FABRIZIO DEL BIANCO,3 ALESSANDRA MERCORELLA,2 MICHAEL NONES,4 LUCA 5 6 7 CROSE, MASSIMO GUERRERO, AND JEFFREY A. NITTROUER 1University of Aberdeen, School of Geosciences, Aberdeen, U.K. 2Institute of Marine Sciences, ISMAR-CNR, Bologna, Italy 3Consorzio ProAmbiente, Bologna, Italy 4Research Centre for Constructions, Fluid Dynamics Unit, University of Bologna, Bologna, Italy 5Agenzia Interregionale per il Fiume Po, AIPO, Settore Navigazione Interna, Parma, Italy 6Department of Civil, Chemical, Environmental and Material Engineering, University of Bologna, Bologna, Italy 7Rice University, Department of Earth, Environmental, and Planetary Sciences, MS-126, Houston, Texas 77005, U.S.A. e-mail:
[email protected] ABSTRACT: River systems evolve in response to the construction of dams and artificial reservoirs, offering the possibility to investigate the short-term effects of base level oscillations on fluvial architecture. A major effort has been dedicated to the understanding of river response downstream of large dams, where deep channel incisions occur in response to the removal of sediment that is sequestered in the upstream reservoir. Integrating field observations and numerical-modeling results, this work quantifies the sedimentary and morphological changes of the Po River (Italy) upstream of the Isola Serafini dam to investigate the impact of dam-induced backwater on river morphodynamics. The construction of a reservoir generates a new base level that forces an upstream shift of alluvial lithofacies and a change in the planform geometry of the river.