Naslov
Changes in channel morphology of the Cetina River since the end of the 19th century (Central Mediterranean)

Autori
Pavlek, Katarina ; Faivre, Sanja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Ex-aqua 2019, Palaeohydrological extreme events evidence and archives, INQUA, Abstract volume / - , 2019, 7-7

Skup
Palaeohydrological Extreme Events Evidence and Archives (EX-AQUA 2019)

Mjesto i datum
Zagreb, Hrvatska, 26.09.2019. - 29.09.2019

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
fluvial geomorphology, aerial images, historical maps

Sažetak
Since the end of the 19th century, river channels across Europe have been noticeably modified by human impacts and climate change. Channel narrowing and incision, followed by changes in river ecosystem and habitat loss are mostly caused by dam construction, river channelization and land cover changes (Gregory, 2006). Channel morphology of the Cetina River in southern Croatia has also been significantly affected by climate changes, construction of hydropower plants, and socio-economic changes. This study investigates geomorphological changes of the Cetina River channels over the last 130 years using historical maps, archival aerial images and contemporary orthophotos. The river was divided in 15 segments based on geomorphological, geological and hydrological features of the river valley. A detailed digitalisation and analysis of the channel features was performed in GIS. In the period up to the mid-20th century, partial narrowing of the channel and drying of marsh zones in the source area were recorded, possibly due to reduced humidity and discharge following the end of the Little Ice Age (Grove, 2001 ; Faivre et al., 2019). The expansion of fluvial bars can also be connected to the drop in discharge and an increased sediment flux caused by noted population growth and agricultural intensification (Magliulo et al., 2016). A considerable progradation of the river delta during this period can be primarily seen as a consequence of the increased erosion rate of the flysch hinterland. Similar results were found for the river mouths on the Istrian Peninsula (Faivre et al., 2011 ; Benac et al., 2017). In the last 50 years, five big hydroelectric power plants (HPPs) were built in the catchment. The operation of the HPPs caused severe reductions in discharge (Bonacci and Roje-Bonacci, 2003), which led to channel narrowing by about 50% in the third of the river length. Apart from the dam construction, a reduction in the area of fluvial bars by 85% and an increase in the number of islands by 103% can be related to a decreased sediment supply following land abandonment and natural reforestation in the catchment (Boix-Fayos et al., 2007). Recent degradation of the river channel is thus largely caused by human activities. In the light of climate change projections, which forecast further drying and warming in the Mediterranean region during summer months (Giorgi and Lionello, 2008), the sustainability of the present situation is questionable. The results of this study add to the knowledge on river morphology in the Mediterranean environment and represent a starting point for the potential restoration plans of the Cetina River.

Izvorni jezik
Engleski

Znanstvena područja
Geografija

POVEZANOST RADA