Impact of Inland Navigation on the Environment – INFLUE

The French river network consists of approximately 18,000 km of waterways, of which 8,500 km are navigable. This network includes rivers and canals that have been developed and opened for transport. France has one of the longest networks of navigable waterways in Europe. This mode of transport has the advantage of generating lower CO2 emissions than road transport per tonne transported. Overall, over the last decade, inland waterway transport has intensified, notably with an increase in the volumes transported. This strong modal shift towards river transport therefore generates new issues such as clean, economical, safe and intelligent ships. This implies research into manoeuvrability, fuel consumption and the environmental impact of navigation. There are many issues at stake: better dimensioning of infrastructures in relation to the evolution of the fleet and climate change, studying facilities in relation to the problems of agitation, stability, crossing or reflection of waves. Inland navigation intervenes in an environment that is not only fragile, due to the richness of its biodiversity, but also highly dynamic and variable. In this context, the hydrodynamic problems related to the river environment will become a key issue in order to optimize the use of waterways while protecting the environment and its biodiversity, whether ecological or related to heritage. Indeed, navigation has a direct impact on the balance of the river ecosystem. the waves generated by vessels destruct the riverbanks and channels. This erosion phenomenon is mainly related to the wave heights generated by vessels wake and to the significant flow velocity generated by their passage through the waterway. Many parameters govern the formation and propagation of these waves and related flow velocity: geometry of the waterway, shape and speed of the boat, velocity and direction of the current, type of bank layout, and so on. Although several studies have already been carried out with this in mind, they have not made it possible to quantify the instantaneous impacts of hydrodynamic action. As a consequence, it is essential to understand the influence of ship and channel parameters on flow and sediment transports in rivers in order to implement the appropriate structural arrangements to minimise the impact of inland navigation on the environment. This challenge is essential for the manager to ensure an economical and environmentally friendly means of transport. Based on the skills and resources of the partners, INFLUE focuses on the impact of navigation on the river environment. Identifying hydrodynamic and the interaction of the generated flow with sediment are important for of the channel management, including waterway planning, navigation-related problems in busy waters, riverbank protection, and sediment continuity in the river. The knowledge gap is mainly due to the many and complex interacting factors that are involved in the erosion process, especially when ship waves and resulted currents are present. The complexity of factors affecting erosion rates involves (i) waves and currents induced by ships that vary in size, speed, loading, and traveling distances from the bank, (ii) spatially varying bank geotechnical characteristics, (iii) entrainment rates of bank material and its characteristic. It is particularly difficult to isolate the effects of the single factors due to their simultaneous occurrence and mutual interactions. INFLUE objectives are to characterize the local processes that determine the evolution of unprotected banks in navigable regulated rivers in order, finally, to establish predictive models to quantify the riverbank stability. To achieve, detailed investigations are needed to better characterize the factors controlling hydrodynamics due to ship motion in confined water. Study of processes that drive bank erosion and stability, integrate the roles of relevant factors such as sediment characteristics is proposed.