| dc.description.abstract | One-dimensional (1D) numerical models generally provide reliable results when applied
to simulate river hydraulics and morphodynamics upstream of the tidal influence, given the
predominantly unidirectional flow conditions. Such models, however, can also be used to reproduce
river hydraulics across the fluvial to marine transition zone when specific conditions occur, as
during high discharge events, and the results obtained via these simple modeling tools can provide
indicative trends that may guide more structured and detailed modeling of a particularly critical
area. In this study, the application of a 1D model setup with hydrologic engineering centers river
analysis system (HEC-RAS) for simulating the hydro-morphodynamic conditions of a distributary
channel of the Po River Delta (Italy) during a flooding event that occurred in Spring 2009 is
presented. The channel bathymetry and the grainsize composition was taken from field
measurements, while the dimension of the plume offshore the delta was derived from a MODIS
image acquired at the peak of the flood. The comparison between the numerical outcomes and the
field evidence shows the reliability of the proposed 1D modeling approach in representing the delta
dynamics at a large scale, as well as in showing locations where more spatially detailed studies are
needed. The code was also able to adequately reproduce the channel hydro-morphodynamics and
the sediment data as derived from a core sample taken a few km offshore during the flooding event
of April–May 2009. Through a sensitivity analysis, it is also proven that the dimension of the river
plume can influence the evolution of the prodelta, while having a rather negligible effect inland,
because of the major stresses induced by the high river discharge during the flood event. | en_US |
