The Tagliamento River: The Fluvial Landscape and Long-Term Evolution of a Large Alpine Braided River

The Tagliamento River represents a reference system to observe natural, or semi-natural, forms and processes in the Alpine environment. In this chapter, the morphology of the Tagliamento in its lower sector (i.e. in the Friulian Plain) and the medium-long-term evolution of the river are described. The river is very wide and has a spectacular braided pattern. Its morphology undergoes rapid and abrupt changes, such as channel avulsion and bar formation or destruction. Islands are a distinct feature in this river and they are characterized by a rapid turnover. Besides recent channel adjustments due to some human interventions, the Tagliamento has undergone a complex evolution in the last 30,000 years and formed an alluvial megafan. Since the Last Glacial Maximum the downstream limit of gravel transport and channel typology have changed dramatically in response to climate change and sea-level variations.