Large wood recruitment and transport during large floods: A review

摘要: Large wood (LW) elements transported during large floods are long known to have the capacity induce dangerous obstructions along channel network, mostly at bridges and hydraulic structures such as weirs. However, our current knowledge of transport dynamics high-magnitude flood events is still very scarce, because these (locally) rare thus unlikely be directly monitored. Therefore, post-event surveys invaluable ways get insights (although indirectly) on LW recruitment processes, distance, factors inducing deposition — all aspects that crucial for proper management river basins related hazard mitigation. This paper presents a review (quite limited) literature available floods, drawing extensively authors' own experience in mountain piedmont rivers, published unpublished. The overall picture emerging from studies points high, catchment-specific variability different processes affecting floods. Specifically, phase, relative floodplain (bank erosion) vs. hillslope (landslide debris flows) contribution rivers varies substantially, it relates extent widening (which depends many variables itself) but also hillslope-channel connectivity mobilized slopes. As phase within appears widely characterized by supply-limited conditions; whereby rates (and volumes) ultimately constrained amount made flow. Indeed, was (in terms volume) observed artificial (bridges) documented events. implies estimation assessment clogging probabilities each structure (for event given magnitude) most important prediction magnitude any cross section network. Finally, discusses optimal strategies manage LW-related hazard, which should consider riparian vegetation in-channel dead key components ecosystems interfere with (as well sediment) only limited spatial temporal scales.