We performed a comprehensive study of the generation and transport
mechanisms of a river plume flowing into a microtidal environment.
First, we analysed images simultaneously acquired by both two
shore-based stations and satellite and correlated the plume offshore
extension with the estuarine forcing. Furthermore, we run numerical
simulations to reproduce real-life events, characterized by a
combination of forces, and to distinguish the role of each forcing. We
identified the river discharge and the wind as the main generation and
transport mechanisms, respectively. Moreover, waves were able to both
generate and drag plumes. Results showed that a river discharge
associated with a return period of 1 year produced a denser plume than
10-years return period waves. The transport mechanisms were responsible
for the alongshore extension of the plume and consequent potential
nourishment of the beaches. The tide, even if secondarily, could affect
the plume evolution, depending on its phase shift with respect to the
river discharge peak. Finally, we used Particle Tracking Velocimetry on
videos acquired by a shore-based station to obtain the surface velocity
field in the final river stretch. Such velocity was then modified to
consider the effect of wind and waves, so that it could be correlated
with the plume extension. The relation between the along-river component
of the plume velocity and the plume extension followed a linear law with
angular coefficient inversely proportional to the alongshore component
of the plume velocity.