On integrated sediment transport modelling for flash events in mountain environments

Sediment production and transport in mountain basins during short-term, intense events depend on a variety of processes. Available models typically consider a limited portion of the phenomenological chain, frequently either sediment supply or solid transport along the waterways. On the other hand, proper depiction of on-site processes requires ability to model all the process stages and suitable integration between different models. In this manuscript, an integrated modelling is attempted for small catchments in Italian Alpine foothills. The integrated approach has involved: (i) hydrologic estimation of peak discharge, (ii) evaluation of the volumetric sediment supply into the stream, and (iii) computation of the morphologic evolution of the river bed. The results are discussed focussing on: (i) the feasibility of a joint modelling like the one presented, in the light of all the limitations imposed by the different nature of hillslope-devoted and river-devoted models; and (ii) the sensitivity of the obtained results to some parameters, for an assessment of result reliability.