Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. 1The following paper is the final version prior to publication on 22 September 2015. are proposed, the way in which indicators could contribute to classification is discussed. All of the methods described in Table 1 consider a hierarchy of spatial units, but the degree to which they develop the other aspects of the conceptual approach proposed by Frissell et al.(1986) varies widely.2. Many of the frameworks focus entirely on hydromorphological processes and forms that are either directly measured or inferred. This is because interactions between processes and forms control the dynamic morphology or behaviour of rivers and their mosaics of habitats.Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of physical habitats, and the sedimentary and vegetation structures associated with those habitats.3. Some frameworks are conceptual, providing a way of thinking about or structuring analyses of river systems, and interpreting their processes, morphology and function (e.g. Frissell et al., 1986;Habersack, 2000;Fausch et al., 2002;Thorp et al., 2006;Beechie et al., 2010;McCluney et al., 2014). Some frameworks are more quantitative, generating one or more indices or classifications of spatial units that support assessment of river systems (e.g. Rosgen, 1994;González del Tánago and García de Jalón, 2004;Merovich et al., 2013;Rinaldi et al., 2013Rinaldi et al., , 2015a MacDonald, 2002;Brierley and Fryirs, 2005;Beechie et al., 2010; Rinaldi et al., 2013a Rinaldi et al., , 2015.In some cases, theoretical or historical analyses or consideration of specific future scenarios are used to develop space-time understanding that can support management decisionmaking (e.g. Buffington, 1997, 1998;Montgomery and MacDonald, 2002;Benda et al., 2004;Brierley and Fryirs, 2005;McCluney et al., 2014 , 1997, 1998Montgomery and MacDonald, 2002;Benda et al., 2004;Brierley and Fryirs, 2005;Merovich et al., 2013;Rinaldi et al., 2013Rinaldi et al., , 2015a. Furthermore, some of the frameworks include indicators of human pressures and their impacts (e.g. Merovich et al., 2013;McCluney et al., 2014;Rinaldi et al., 2013Rinaldi et al., , 2015a.6. Finally, although most frameworks could be described as incorporating processes to some degree, some methods are particularly process-based, even when processes are inferred from forms and associations rather than being quantified by direct measurements.Frameworks that consider temporal dynamics and trajectories of historical change (see point 4, above) are particularly effective in developing understanding of processes and the impacts of changed processes cascading through time and across spatial scales.Although the list of frameworks presented in Table 1 is far from comprehensive, ...

The aim of this paper is to explore possibilities and limitations of restoring physical processes in five gravel-bed rivers (Brenta, Piave, Cellina, Tagliamento and Torre Rivers) in north-eastern Italy. The selected rivers were analysed through a range of techniques, specifically analysis of historical maps and aerial photographs with geographical information systems (GIS), comparison of topographic surveys and geomorphological surveys. After illustrating channel adjustments and sediment fluxes, we discuss how the understanding of physical processes can be used for channel restoration.The studied river channels have undergone notable adjustments in the last 100 years, specifically narrowing by up to 76%, incision by up to 8.5 m, and changes in channel configuration. Alteration of sediment fluxes, mainly due to in-channel mining, has been the main factor driving such channel adjustments. Evolutionary trends show that channel recovery is on-going in several of the selected reaches, since widening and aggradation have occurred over the last 15-20 years. This channel recovery has been possible because sediment mining has significantly decreased or ceased along the study reaches. However, several constraints still exist on sediment fluxes (e.g. dams).Four categories of river channel were defined, taking into account the recent evolution of the studied channels (from 'A', high channel recovery, to 'D', no channel recovery). The impact of different sediment management strategies on channel dynamics over the next 40-50 years was then analysed. Without any intervention, channel recovery would only be possible in those reaches that have a relatively high degree of connectivity with upstream sediment sources or tributaries, while further incision and narrowing would be expected in those reaches where connectivity is low. A more substantial channel recovery could be obtained through interventions at reach (e.g. removal of bank protection) and basin (e.g. sediment transfer downstream of dams) scales. Notwithstanding such actions, it is likely that channels will not recover in the next few decades to the morphology they exhibited in the first half of the 20th century, when bed-load yield and connectivity were higher.

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The Tagliamento River, Northeast Italy, represents an important Alpine to Mediterranean braided system, where interactions between river flows, sediment dynamics and vegetated landforms can be investigated within a relatively unconfined setting.We analysed data from contemporary and historical sources, including stage records, photographs and topographic surveys. From these we identified river stages at which thresholds in surface hydrological connectivity and biogeomorphological adjustment appeared to occur, contributing to a shifting habitat mosaic.Significant adjustments in landscape elements within the active tract commence at river stages well below bankfull with return periods of a few months. Flow pulse events with return periods from a few months to 2 years support a dynamic inundation pattern, ranging from a patchwork of isolated water bodies within a predominantly terrestrial landscape at low river stages to isolated vegetated islands within a fully connected aquatic landscape as the river approaches bankfull. Across this range, interactions between flow, sediment and vegetation lead to gradual and abrupt transitions in persistence, form and connectedness of different landscape elements. Bankfull flows (return period over 2.5 years) topple and disperse significant numbers of large trees, seeding the next generation of vegetated patches, and larger floods (return period around 10 years) induce significant turnover of established islands and floodplain surfaces.The results reported in this paper illustrate how extensive interdisciplinary research on a single river system can provide useful insights concerning the time scales and thresholds that characterize water-sediment-vegetation interactions in piedmont reaches of Alpine to Mediterranean braided systems. Anthropogenic effects on river systems are ubiquitous throughout Europe. However, systems such as the Tagliamento River that retain significant process dynamism and morphological integrity, provide a laboratory within which reference processes and process-form interactions can be investigated, understood and then incorporated into innovative restoration design on more impacted systems.

This paper deals with channel evolution over the past 200 yr in 12 selected streams in northern and central Italy and aims at reconstructing the evolutionary trends (e.g., trends of channel width and bed elevation) and understanding the causes of channel adjustments. The selected streams have been studied using various sources and methods (historical maps, aerial photographs, topographic surveys, and geomorphological surveys). The selected rivers have undergone almost the same processes in terms of temporal trends; however, the magnitude of adjustments varies according to several factors, such as original channel morphology. Initially, river channels underwent a long phase of narrowing (up to 80%) and incision (up to 8–10 m), which started at the end of the nineteenth century and was intense from the 1950s to the 1980s. Then, over the last 15–20 yr, channel widening and sedimentation, or bed-level stabilization, have become the dominant processes in most of the rivers. Different human interventions have been identifi ed as the causes of channel adjustments in Italian rivers (sediment mining, channelization, dams, reforestation, and torrent control works). Such interventions have caused a dramatic alteration of the sediment regime, whereas effects on channel-forming discharges have seldom been observed. Some notable implications for river management and restoration are (1) the state of rivers before major human disturbances and channel adjustments can rarely be taken as a reference, as at present rivers are far from their pristine condition; and (2) sediment management is and will be a key issue in such fl uvial systems