1,721,139 research outputs found
Impact of limitations in sediment supply on bed load transport in the instrumented catchment of the Rio Cordon, Italy
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The response of a mountain drainage basin to extreme events: the impact of Vaia storm on Rio Cordon (Dolomites, Italy)
No full textCurrent literature is limited in understanding the responses of mountain basins to large disturbances, especially when it comes to integrating analyses of sediment transport, geomorphic changes, and topographical conditions, as these aspects are often examined at varying spatial scales. This manuscript explores the impact of the Vaia storm (27-30 October 2018) on the Rio Cordon Basin (Dolomites, Italy). Integrating data from three studies conducted at different spatial scales, it examines hydrological, geomorphological, and sedimentological responses of the basin to the large infrequent event. The findings encompass changes in channel network, step-pool morphology evolution, and sediment flux alterations. Streambed remobilization, boulder mobility, incision, and lateral erosion were observed. The step-pool morphology experienced disruption but recovered to stability within two years. Surprisingly, suspended sediment fluxes and yields after two years form the event (42 t km-2 years-1) were consistent with pre-Vaia conditions (40 t km-2 years-1). The integration of pre- and post-event data proved valuable for understanding the basin's responses to extreme events. Based on current conditions, Rio Cordon appears to be returning to a pre-event state, establishing a new dynamic equilibrium, as the Vaia event induced morphological changes while sediment fluxes and step-pool stability remained in line with pre-event conditions
Bedload dynamics in steep mountain rivers: Insights from the Rio Cordon experimental station (Italian Alps)
No full textInteranual variation of suspended sediment load and sediment yield in an alpine catchment
No full textRegimen theories in gravel bed rivers: preliminary comparison between disturbed rivers due to antrophic activities (Northeastern Italy) and natural rivers (Patagonia, Argentina)
No full textLong-term monitoring of bedload and debris flows in two small alpine basins of different morphological settings
No full textEffective discharge for sediment transport in a mountain river: computational approaches and geomorphic effectiveness
No full textDominant, effective, bankfull and channel-forming discharges are different concept-based flows, often applied as design
parameters in river management and restoration. In order to achieve a better understanding of channel-forming conditions in
high-gradient, boulder-bed streams, the long-term sediment loads data obtained from the Rio Cordon (Italian Alps) measuring
station have been analysed. The effective discharge (Qe, calculated using both Wolman and Miller’s method and the so-called
‘mean’ approach) for bedload transport proves to be more appropriate than that determined for the suspended sediment load in
describing the channel formation and maintenance for this type of channels. The analysis demonstrates that Qe is strongly
influenced by the number of flow classes, the fraction of transported sediments and the methodology used in its computation.
The result questions the appropriateness in considering Qe as an unique value, and also suggests the possible definition of two
dominant discharge ranges for steep mountain rivers: (a) a relatively frequent flow range responsible for maintaining channel
form; and (b) a more infrequent high flow range responsible for macro-scale channel shaping
La resistenza al flusso in un torrente montano ad elevata pendenza con morpologia a step-pool
No full textMulti-temporal analysis of morphological changes in an Alpine proglacial area and their effect on sediment transfer
No full textProglacial areas in high-mountain environments are among the most dynamic landscape zones in terms of morphological, sedimentological, and hydrological changes. In fact, in such areas both glacial and paraglacial dynamics exert a strong control on water fluxes (and thus on bedload transport capacity) and on sediment supply. Because of the rapid changes undergoing in these environments, the understanding of the dynamics of sediment transfer and the prediction of how this will change in future still remain a challenge. In this study, we used four different high-resolution topographic surveys to quantitatively analyse the spatio-temporal patterns of sediment transport that occurred in the proglacial area of the Sulden glacier (South Tirol, Italy). The topographic surveys covered the period 2013–2019 and – by building DEMs of difference (DoDs) – we calculated the volumes of erosion and deposition occurring at the glacier terminus and along its outflow channels. Our results indicate that, within the analysed time-period and for different areas, erosion and deposition generally show similar values, suggesting that the analysed proglacial areas has been acting both as a sediment trap and as a sediment source for the downstream river reaches. In addition, the results indicate a complex morphological dynamics, which have strongly impacted coarse sediment connectivity in the upper catchment. In particular, high temperatures and the recent and rapid glacier melt, have promoted a direct control on the structural connectivity within the proglacial area. Morphological changes have increased or decreased sediment connectivity depending on pre-existing morphological features. In contrast, extreme precipitation events, both in term of rainfall and snowfall, have locally and temporally increased the functional connectivity, sometimes leading to long-term modifications in the proglacial area. Overall, in the analysed time-period sediment transfer has been extremely dynamic, suggesting that sediment in the downstream river channel may have been supplied with irregular pulses associated with the morphological changes taking place in the proglacial area
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