We report on a multidecadal analysis of alternate bar dynamics in a 41.7 km reach of the Alpine Rhine River, which represents an almost unique example of a regulated river with fixed levees, straight reaches, and regular bends in which alternate gravel bars spontaneously formed and migrated for more than a century. The analysis is based on freely available Landsat imagery, which provided an accurate and frequent survey of the dynamics of the alternate bar configuration since 1984. Bars were characterized in terms of wavelength, migration, and height. Longitudinal and temporal patterns are investigated as a function of flood occurrence and magnitude and in relation to the presence of local planform discontinuities (bends and ramps) that may affect their dynamics. Bars in the upper part of the reach are mostly steady and relatively long (about 13 channel widths); bars in the lower part of the reach are migrating and shorter (about 9 channel widths). Bar height is rather uniform along the reach, ranging between 3 and 4 m. The temporally long hydrological data set allowed the investigation of bar migration during flood events, showing that bars migrate faster for intermediate floods. The observed relationship between bar migration and wavelength was consistent with linear theories for free migrating and steady forced bars in straight channels. The comparison of theories with observations highlights the key role of theories to support interpretation of observations, for a better understanding of the morphodynamic processes controlling bar formation and dynamics. Key Points:Bar wavelength, migration, height investigated for 40 bar units over 30 years Bar wavelength-migration relation consistent with analytical theories Satellite imagery provides long-term data on bar dynamics in the Alpine

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(1) Background: The application of concepts linked to the circular economy (CE) has led to a sudden development of studies in numerous fields. However, the level of environmental sustainability of CE strategies could be improved and this topic deserves more attention by the scientific community. This research addresses this gap and aims at presenting a new concept, named circular ecology (CEL), and its application to the field of waste management. (2) Methods: The paper presents a literature review on the criticalities of CE and on examples of studies that implement the CEL principles. (3) Results: The review highlights that CEL principles are widely applied to several fields of waste management, showing promising opportunities to export the results to other geographical contexts. (4) Conclusions: If supported by governments, CEL approaches may allow solving multiple environmental problems at once, with clear economic, time, resources, and emission savings.

One of the problems of food waste management is the acceptability of the treatment plants at local level because of the risk of odours. Anaerobic digestion as first step before composting has contributed to solve this problem, but, in the sector, it remains an opposition to large plants. That affects also food waste anaerobic digestion: people's perception is that the stream coming at the gate of the plant is not theirs. The present paper shows an alternative to the conventional approach. The aim is to reduce the scale of the intervention giving a solution also to small municipalities or to an aggregation of small municipalities. The basic idea is suitable for adaptations depending on the local availability of manure and other plants specialised on wastewater. The integrability of these plants allows reducing the costs for treating secondary streams to be managed, as discussed in the article. The extreme technological scenario is based on an anaerobic digester with unconventional pre-treatment of food waste and energy recovery, on a hydro-thermal carbonisation reactor for manure, on an ammonia separator for product recovery (by stripping), on a CO 2 separator (from off-gases), on a hydro-biochar flusher for opening to land application and on mechanised small-scale composters for small communities. The principles of the circular economy are adopted, but the economic balance is affected by the transport costs of the products. The suitability of this approach to medium income countries is discussed too.

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