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Keynote: Hervé Piégay

Fluvial Geomorphologist, Research Director at the National Center for Scientific Research (CNRS)

Hervé Piégay, research director at the National Center of Scientific Research, got his Ph.D. in 1995 on the interactions between riparian vegetation and channel geomorphology. Since 1995 he is continuing his studies at the University of Lyon (Ecole Normale Supérieure of Lyon), France. He is a fluvial geomorphologist involved in integrated sciences for rivers, strongly interacting with hydraulic engineers, freshwater ecologists and practitioners (Water Agencies, Regions, Ministry of Ecology, French agency for biodiversity, Compagnie Nationale du Rhône, and EDF, the main French hydroelectric company). He is working on river management, planning and restoration, developing methodological frameworks and tools using GIS and remote sensing. He has contributed to more than 200 papers in peer-review journals and book chapters and has coordinated several edited books such as Tools in Fluvial Geomorphology – Handbook for ecologists and practitioners with M.G. Kondolf (2003, 2015), Gravel-bed rivers 6 : From process understanding to river restoration with H. Habersack and M. Rinaldi (2007) or fluvial remote sensing for science and management with P. Carbonneau (2012). He received in 2018 the Linton Award of the British Society for Geomorphology.

Making room for rivers : why and how should we do that?

Wed 9:00 am

Making room for rivers (MRR) is an inspiring solution to live with rivers in a sustainable way, a so-called nature-based solution. It can be difficult to implement in highly populated alluvial valleys and a significant collective effort is needed to make it successful. MRR can be a conservation option to prevent additional human pressures on the river corridor or a restoration option considering we redefine land use along the river towards more naturality. Many locks must be unlocked to implement it, it is a slow process related to our progressive understanding of our place on Earth as humans. Citizens must have an environmental consciousness, be convinced we need to take care of our environment so as to prevent additional damages and survive. Since the 1990s-2000s, some laws have been passed to promote such policy in different parts of the world. The European Water Framework Directive requiring to reach a good ecological status for rivers, can be considered as one of them. In such social context, human attitudes towards natural processes are evolving. Flooding, bank erosion, in-channel wood in rivers were seen as problems during previous centuries, whereas they are also valuable processes for river health, humans and non-humans benefiting river services. Levee (stopbank) setback is a policy to manage floods within an integrated catchment scale perspective, considering inhabitants living upstream, along the concerned reach … and downstream, considering non-humans, considering the next five years… and a much longer time scale having in mind a potential trajectory of change. Different strategies or tools have been implemented to make room for rivers within a process-based thinking. I will introduce a few examples from the Western European Alps such as the erodable corridor concept (1998), the sectorised vegetation maintenance (1998) or the good river functioning corridor (2016) and discuss the need to have a transdisciplinary and multi-scale strategy to live with rivers and be resilient to changes.