Numerical modelling of uncongested wood transport in the Rienz river

Environmental Fluid Mechanics - The Eulerian–Lagrangian model ORSA2D_WT is employed for the simulation of uncongested wood transport, with reference to a field experiment that studied the...     

Toward participatory decision-making in river corridor management: two case studies from the European Alps

River managers are aware that river restoration entails addressing and effectively solving wicked social-ecological problems. Contemporary river corridor management is characterized by a variety of actors with different perspectives and interests, and by complex institutional settings and legal landscapes. Additionally, at the intersection between litho-, hydro-, and biological fields, new research suggests that river restoration should reactivate matter and energy fluxes, re-establish spatial connections with the floodplains, and enhance aquatic and terrestrial habitats without exacerbating flood risk. First, we outline a general structure of participatory river corridor management that addresses the following key requirements: (1) unambiguous, participatory spatial delineation of the river corridor; (2) comprehensive assessment of the river corridor's hydro-geomorphological, ecological, socio-economic and cultural processes; (3) transparency and consistency of the decision-making process; as well as (4) a coherent envisioning process. Subsequently, we present an overview of two river corridor management processes, conducted in South Tyrol, Italy. Specifically, we analysed the Etsch/Adige River corridor between Laas/Lasa and Glurns/Glorenza in the Upper Vinschgau/Venosta valley characterized by intense agricultural land use and the densely populated Eisack/Isarco River corridor in Brixen/Bressanone. Based on structured interviews with project managers, we highlight strengths and shortcomings of the proposed participatory management and envisage procedural improvements.     

Developing consistent scenarios to assess flood hazards in mountain streams

The characterizing feature of extreme events in steep mountain streams is the multiplicity of possible tipping process patterns such as those involving sudden morphological changes due to intense local erosion, aggradation as well as clogging of critical flow sections due to wood accumulations. Resolving a substantial part of the uncertainties underlying these hydrological cause-effect chains is a major challenge for flood risk management. Our contribution is from a methodological perspective based on an expert-based methodology to unfold natural hazard process scenarios in mountain streams to retrace their probabilistic structure. As a first step we set up a convenient system representation for natural hazard process routing. In this setting, as a second step, we proceed deriving the possible and thus consistent natural hazard process patterns by means of Formative Scenario Analysis. In a last step, hazard assessment is refined by providing, through expert elicitation, the spatial probabilistic structure of individual scenario trajectories. As complement to the theory the applicability of the method is shown through embedded examples. To conclude we discuss the major advantages of the presented methodological approach for hazard assessment compared to traditional approaches, and with respect to the risk governance process.