On integrated sediment transport modelling for flash events in mountain environments

Abstract

A b s t r a c tSediment production and transport in mountain basins during shortterm, 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.

Remote Sensing for Landslide Investigations: An Overview of Recent Achievements and Perspectives

“…The analysis of erosion phenomena deserves a separate mention, which may contribute to the creation of debris flow in rivers and hence they may result in sediment supply being involved in subsequent landslides [226] or debris flows [291]. Estimation of eroded volumes is not straightforward: in the literature, there are some empirical formulae aimed at furnishing the magnitude of the sediment supply, but the best approach is to quantify it by means of laser scanning and photogrammetry [121,122,129,204,235].…”

Monitoring Riverbank Erosion in Mountain Catchments Using Terrestrial Laser Scanning

“…Soil erosion has several on-site and off-site impacts on the environment: (1) loss of fertile soil with important consequences on agriculture [1]; (2) silting of reservoirs that reduces the storage capacity and interferes with dam operations [2][3][4]; (3) migration of pollution in which sediment transport is considered a means of transport for contaminants [5,6]; (4) increase of flood risk [7] and debris flow events [8]; and (5) geomorphic evolution of river beds [9] with possible impacts on the surrounding structures. At the basin scale, sediment production is the result of the complex interaction between different geomorphic processes: splash erosion, sheet erosion, rill erosion, gully erosion, bank erosion as well as mass movements [10].…”

Generation of a Design Flood-Event Scenario for a Mountain River with Intense Sediment Transport

“…Such a condition also favors the use of a single sediment size mimicking a granulometric distribution. Furthermore, the studies of [16,17,37] demonstrated (in the former case, for the same river considered here) that aggradation patterns in a downstream portion of a computational reach were almost independent of the sediment supply, provided that the duration of the modeled event was short. This piece of information was used to choose the extent of the computational domain, as already mentioned in Section 3.…”

“…These data were used as benchmarks for the simulation. In this way, an attempt was made to overcome the lack of field validation that is frequently a shortcoming in similar studies (e.g., [37,38]). …”