Field and flume measurements with the impact plate: effect of bedload grain‐size distribution on signal response

2021 ◽  
Author(s):  
Tobias Nicollier ◽  
Dieter Rickenmann ◽  
Arnd Hartlieb
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Signal Response ◽  
Impact Plate ◽  
The Impact

scholarly journals Linking flow-stream variability to grain size distribution of suspended sediment from a satellite-based analysis of the Tiber River plume (Tyrrhenian Sea)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
J. Pitarch ◽  
F. Falcini ◽  
W. Nardin ◽  
V. E. Brando ◽  
A. Di Cicco ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Suspended Sediment ◽  
Grain Size Distribution ◽  
Flash Floods ◽  
Sandy Sediment ◽  
Tyrrhenian Sea ◽  
Tiber River ◽  
The Impact

AbstractSeveral coastal regions on Earth have been increasingly affected by intense, often catastrophic, flash floods that deliver significant amounts of sediment along shorelines. One of the critical questions related to the impact of these impulsive runoffs is “are flash floods more efficient in delivering non-cohesive sandy sediment along the coasts?” Here we relate flow stages (i.e., from erratic to persistent) to the grain size distribution of the suspended load, by performing a synergic analysis of in-situ river discharge and satellite-retrieved grain size distribution, from 2002 to 2014, covering the 2012 Tiber River (Italy) exceptional flood event. Our analysis shows novel and promising results regarding the capability of remote sensing in characterizing suspended sediment in terms of grain size distribution and reveals that erratic stages favour delivering of non-cohesive sandy sediment more than the persistent stages. This conclusion is supported by numerical simulations and is consistent with previous studies on suspended sediment rating curves.

scholarly journals Sensitivity of Volcanic Ash Dispersion Modelling to Input Grain Size Distribution Based on Hydromagmatic and Magmatic Deposits

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 567 ◽  
Author(s):  
Sara Osman ◽  
Frances Beckett ◽  
Alison Rust ◽  
Eveanjelene Snee
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Volcanic Ash ◽  
Sensitivity Study ◽  
Dispersion Modelling ◽  
Grain Size Distributions ◽  
Ash Dispersion ◽  
The Impact ◽  
Coarse To Fine

The size distribution of volcanic ash is rarely measured in real time and Volcanic Ash Advisory Centres (VAACs) often rely on a default particle size distribution (PSD) to initialise their dispersion models when forecasting the movement of ash clouds. We conducted a sensitivity study to investigate the impact of PSD on model output and consider how best to apply default PSDs in operational dispersion modelling. Compiled grain size data confirm that, when considering particles likely to be in the distal ash cloud (< 125 µm diameter), magma composition and eruption size are the dominant controls on grain size distribution. Constraining the PSD is challenging but we find that the grain size of deposits from large hydromagmatic eruptions remains relatively constant with distance, suggesting that total (whole-deposit) grain size distributions (TGSDs) for these eruptions could be estimated from a few samples. We investigated the sensitivity of modelled ash mass loadings (in the air and on the ground) to input PSDs based on coarse to fine TGSDs from our dataset. We found clear differences between modelled mass loadings and the extent of the plume. Comparing TGSDs based on ground-only and ground-plus-satellite data for the Eyjafjallajökull 2010 eruption, we found that basing input PSDs on TGSDs from deposits alone (likely missing the finest particles) led to lower modelled peak ash concentrations and a smaller plume.

Grain size distribution in evaporated permalloy films

1970 ◽  
Vol 2 (2) ◽  
pp. K69-K73 ◽  
Author(s):  
M. Reinbold ◽  
H. Hoffmann
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution
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