Surface-subsurface flow modeling of leveed river systems affected by mammal bioerosion
RAMB
Abstract
Burrowing mammals such as crested porcupines, badgers, red foxes, and coypus are recognized by agencies responsible for levees to have an adverse impact on the integrity of these flood control structures. There is, however, an urgent need to further raise awareness and tackle the emergent risks connected to the impacts of burrowing mammals. In fact, wildlife movement and activity along fluvial systems are rapidly increasing in many regions of the world as a result of changes in animal population, land use, and climate. In addition, the combined effect of hydroclimatic variability and animal-induced levee weakening exposes the protected land to a dramatic increase in flood risk. Solving this problem through targeting the elimination of burrowing mammals along fluvial systems is unpractical due to legislative, technical, and ecological constraints. The combined objective of maintaining the functionality of levees and of preserving species diversity along the fluvial systems needs therefore to be addressed. In this perspective, the main goal of this proposal is to achieve a better understanding of the response of disturbed levees to hydroclimatic forcing and of the behavior of burrowing mammals along fluvial systems. The main elements of the proposed research include full-scale experiments, real case studies, advanced monitoring and modeling. The response of disturbed levees to destructive hydroclimatic forcing will be observed in open-air laboratories obtained by constructing experimental reservoirs in safely floodable areas chosen inside the floodplains of Panaro and Secchia Rivers. The experimental reservoirs will be formed by full-scale levees with artificial disturbances having the same geometry of observed dens. High-resolution geophysics and small-scale tracking of 3D animal movements inside the den will be integrated to provide accurate descriptions of den geometry.
The effects of direct rainfall on the levees will be investigated by raising the water level in the reservoirs during real rainfall events. Mechanistic modeling of the response of levees to possible hydroclimatic scenarios will be conducted by combining state-of-the-art models of coupled surface-subsurface flow, hydraulic-geomechanical models of the relevant failure mechanisms, and observations collected in the field by using advanced hydrological, geomechanical, geophysical, and ecological methods. Surface-subsurface flow models developed and tested through the experiments conducted in open-air laboratories will be used to estimate the impact of mammal bioerosion along real channel reaches of Panaro and Secchia Rivers. Project results are expected to significantly advance our understanding of complex bio-geo-hydrological interactions, so that the best monitoring and nature-based remedial actions in flood risk and wildlife management can be identified. Project activities and results will be disseminated to citizens and administrative bodies responsible for levee management.
Team di ricerca UNIBO
Partner di progetto
UniMORE (Coordinamento), UniFI