River channel adjustment in Southern Italy over the past 150 years and implications for channel recovery

Multi-temporal GIS analysis of topographic maps and aerial photographs along with topographic and geomorphological
surveys are used to assess evolutionary trends and key control factors of channel adjustments for
five major rivers in southern Italy (the Trigno, Biferno, Volturno, Sinni and Crati rivers) to support assessment
of channel recovery and river restoration.
Three distinct phases of channel adjustment are identified over the past 150 years primarily driven by human disturbances.
Firstly, slight channel widening dominated from the last decades of the nineteenth century to the
1950s. Secondly, from the 1950s to the end of the 1990s, altered sediment fluxes induced by in-channel mining
and channel works brought aboutmoderate to very intense incision (up to 6–7m) accompanied by strong channel
narrowing (up to 96%) and changes in channel configuration from multi-threaded to single-threaded patterns.
Thirdly, the period from around 2000 to 2015 has been characterized by channel stabilization and local
widening. Evolutionary trajectories of the rivers studied are quite similar to those reconstructed for other Italian
rivers, particularly regarding the second phase of channel adjustments and ongoing transitions towards channel
recovery in somereaches. Analyses of river dynamics, recovery potential and connectivity with sediment sources
of the study reaches, framed in their catchment context, can be used as part of awider interdisciplinary approach
that views effective river restoration alongside sustainable and risk-reduced river management.