View source for (23) Advances in simulating fluvial sediment transport at basin-scale

==Author==

Albert J. Kettner

CSDMS, INSTAAR, University of Colorado, Boulder CO, 80309, 

albert.kettner@gmail.com

==Abstract==

Recently significant advances have been made in estimating fluvial sediment transport that involves glacial processes, floodplain dynamics and tectonic forcings. Models to quantify the amount of sediment transported by a single or multiple
river  to the ocean have bee   developed for decades. Field observations are difficult and costly to obtain, so that predictive models are still neede   t   estimate the flux of sediment, which importantly influences the downstream coastal, deltaic, and marine environments.
Existing empirical models estimate sediment fluxes per river drainage basin by incorporating easy to obtain inputs: drainage basin properties (drainage area, relief, lithology) and climatological parameters (precipitation, temperature).	first order approach incorporates glacial erosion processes to be able to simulate fluvial fluxes ove  glacial-‐interglacial timescales. These first-‐generation models calculat   solely the suspended sediment flux at the rivermouth (1D) and definitely d   not reflect all processes that interact with the terrestrial sediments. However the impact of long-‐ term climate change or human interaction o   the landscape are well captured.
Recen  advance  make it possible to simulate global fluvial fluxes throughout a drainage basin (2D) a	6-‐arc minute resolution (i.e. the WBMsed model). B increasing the spatial dimension we now can identify sediment hotspots (sources and sinks) i   th   terrestrial landscape and keep track of sediment routing through a rive  system. Furthermore, the WBMsed model i  able to capture th   process of deposition of sediments i   floodplains during pea   floods; it thus dynamically reduces the sediment load ultimately reaching the ocean. Another major advance is incorporating the impact of seismic activity on the sediment fluxes to the ocean. Data analyzes reveal tha  th   Peak Ground Acceleration (PGA),    globall   available index for seismic activity, has a significant impact on sediment fluxes. Earthquakes
appear to increase the total sediment flux up to    factor 2, even fo  area  that ar   not
known for their tectonic activity (e.g. Europe).
Future advances should more focus on simulating fluvial transport of different 
grain sizes.<br><br>
[[File:Nagasaki-Kettner.pdf|Presentation]]