Channel adjustments in a Mediterranean river over the last 150 years in the context of anthropic and natural controls

摘要: Abstract Evolutionary trajectories and related control factors of the Fortore River (southern Italy) are analyzed over a 150-year period as to assess channel modifications. A multitemporal GIS analysis topographic maps aerial photographs together with geomorphological field surveys were performed. Attention was focused on impact caused by human disturbance, above all presence Occhito dam at only 40 km upstream mouth (central Adriatic coast). Results show that adjustments occurred in three distinct phases primarily driven disturbance diversely affected reaches located downstream dam. From last decades nineteenth century 1950s (phase 1), widening prevailed along whilst narrowing reaches. Major from until end 1990s 2), especially up 81% 98% Narrowing accompanied channel-bed lowering 1 5 m pattern changes prevalence multithread largely prevailing single-thread configurations. In-channel mining, works, hydraulic interventions considered key driving observed adjustments. The closure 1966 had significant permanent effects through overall discharge regulation sediment trapping also proved progressive retreat river area. 2000 2015 3), substantial trend inversion partial aggradation total stabilization As highlighted an integrated recent flood events, latter have played important role recovery Comparison between other rivers southern Italy has allowed us ascertain reconstructed evolutionary quite similar essentially same. In particular, it confirms major structures amount ensuing scarce nil potential regulated