Nature-based solutions (NbS): A management paradigm shift in practitioners' perspectives on riverbank soil bioengineering.

Nature-based Solutions (NbS) are promoted as practical and theoretical solutions that simultaneously provide human well-being and biodiversity benefits. One example is soil bioengineering using construction techniques based on living vegetation, and is frequently used for riverbank stabilization, flood protection, and erosion control. Compared with civil engineering, NbS offer many advantages such as cost reduction, limited impact on the environment, and production of ecosystem services. However, their use is still marginal for riverbank control, especially in urban areas. In this paper, we focus on soil bioengineering techniques for riverbank protection in an urban context from the practitioners' perspective. We question to what extent NbS require a shift in management paradigm. We used qualitative methods to interview 17 practitioners working in the Rhone Alps basin (France). Our results reveal that switching from civil engineering to soil bioengineering is not only a technical change, but also requires a shift from a "predict and control" paradigm to an "adaptive management" paradigm because of three major reasons. First, soil bioengineering techniques require redefinition of the performance of engineering structures with the inclusion of ecological and social dimensions. Second, the adoption of soil bioengineering techniques requires that practitioners, elected people and inhabitants reconsider risk sharing and acceptance. Third, the techniques require practitioners to adopt a new posture, with new soft skills (humility and daring) and a new collective organization (collective feedback). Finally, we identify three levers for a broader use of such techniques: (i) systematic assessment of the ecological, economical, and social benefits of such techniques; (ii) improving risk acceptance and sharing; (iii) fostering of social learning among practitioners through collective or technical feedback.

Perception of braided river landscapes: implications for public participation and sustainable management.

Over the past century, the ecologically-diverse, braided Magra River in Italy has narrowed, incised, and lost many gravel bars due to the riparian vegetation encroachment following the decrease in bedload supply and channel degradation. Motivated by the European Water Framework Directive, river scientists and managers are beginning to plan projects to conserve and restore these dynamic mosaics of rare habitats and processes. To support this objective, a study was conducted to assess how braided rivers are perceived by different social groups in the area. In June, 2006, 127 people were surveyed using a photo-questionnaire consisting of ten photographs that depicted riverscapes with different proportions of water, vegetation, and bed material. Respondents were asked to score each photograph in terms of aesthetic value, beneficial uses, and river management needs. Results showed that the photographs depicting gravel bars were perceived as less aesthetically pleasing, so therefore they need an active management. However, these perceptions differed amongst groups of participants, reflecting their interests and objectives. This paper identifies a distance between scientific and popular attitudes and discusses implications for public participation, support for braided river restoration policy, and environmental education.