Channel changes of the Adige River (Eastern Italian Alps) over the last 1000 years and identification of the historical fluvial corridor

Vittoria Scorpio,Nicola Surian,Maurizio Cucato,Elena Dai Prá,Guido Zolezzi,Francesco Comiti

doi:10.1080/17445647.2018.1531074

Abstract

ABSTRACTA 1:50,000-scale geomorphological map of the Adige/Etsch River valley bottom (NE Italy) is presented. The study area is 115 km long, and it extends between the villages of Merano/Meran and Calliano, including also the terminal segments of 9 major tributaries of the Adige River. Presently, the Adige shows a sinuous to straight morphology owing to massive channelization occurred during the nineteenth century. Fluvial geomorphological features have been mapped through a detailed-scale comparative multi-temporal analysis carried out on several historical maps dating since the eighteenth century, previous thematic maps, geological maps of the Italian ‘CARG’ project, orthophotos (2011) and high – resolution DEMs. The map shows the active river channel, dating to 1803–1805 (before channelization), to 1856-1861 (during channelization) and under present conditions, as well as several paleo-channels dating up to the thirteenth century. The analysis led to define the corridor of historical channel changes, a fundamental tool for river management purposes.

Highlights

Geomorphological mapping of paleo-channels sets a baseline to analyze the evolution of alluvial plains, especially for the identification of fluvial morphodynamic corridors (Rinaldi, Gurnell, et al, 2015), an essential tool for flood hazard prediction when coupled with hydraulic simulation for mapping inundation areas
This paper presents a geomorphological map of a 115 km long segment of the Adige valley bottom in NE Italy and, through its analysis, aims to: (1) assess the planform characteristics of paleo-channels over approximately the last 1000 years; (2) reconstruct channel adjustments during the channelization; (3) assess how channel morphology has changed over the investigated period; (4) delineate the historical river corridor in the framework of an integrated river management, in the perspective of matching flood risk mitigation with environmental restoration
The main focus of Main Map is the fluvial landforms related to the Adige River dynamics

Summary

Introduction

Many studies have analyzed the planform modifications of European rivers over a timescale of decades or centuries and most of them documented remarkable channel changes from the late nineteenth or early twentieth century onwards (Arnaud et al, 2015; Aucelli, Fortini, Rosskopf, Scorpio, & Viscosi, 2011; Comiti et al, 2011; Kiss & Blanka, 2012; Latapie et al, 2014; Ollero, 2010; Provansal et al, 2014; Rădoane, Obreja, Cristea, & Mihailă, 2013; Rovira, Batalla, & Sala, 2005; Scorpio et al, 2015; Surian, Ziliani, Comiti, Lenzi, & Mao, 2009; Zawiejska & Wyzga, 2010). Geomorphological maps are considered as valuable tools providing essential support to river and floodplain management (Wheaton et al, 2015), to date in Italy a limited number of maps have been proposed to analyze geomorphological modifications of a valley bottom (Furlanetto & Bondesan, 2015; Magliulo & Cusano, 2016; Piacentini, Urbano, Sciarra, Schipani, & Miccadei, 2016; Rosskopf & Scorpio, 2013). The Adige boasts the availability of a huge number of accurate large scale historical maps (Mastronunzio & Dai Prà, 2016a, 2016b; Scorpio et al, 2018) – besides earlier paintings

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