EGU General Assembly 2012 © Author(s) 2012 Impact of external forcing and catchment response on sediment flux

Numerical modeling work (Kettner et al., 2009; van Balen et al., 2010) highlighted how major changes of sediment supply occur as a result of upstream climatic changes. On the other hand sediment budgeting work (Brommer et al., 2009; Metivier et al., 1999), evidenced the lack of an upstream sediment supply forcing signal in the marine stratigraphic record. What occurs to the sediment flux signal during its downstream propagation towards the marine domain? How is the climatic and tectonic forcing translated to a sediment flux signal and how is it modified and buffered? Inspired by other studies focused on signal propagation in fluvial drainage systems (Jerolmack et al., 2010; Dens-more et al., 2007; Veldkamp et al., 2001) and sediment flux modeling work (Boogart et al., 2003), we have devel-oped, tested and applied a new catchment numerical modeling tool to investigate sediment flux signal generation and downstream propagation in river catchments: PaCMod. PaCMod (Palaeo-Catchment Model) is a spatially lumped model which, based on climatic data, drainage basin characteristics and a number of user defined parameters, calculates long time series (103-106years) of fluvial water discharge and sediment load at the catchment outlet. Key aspects of the model are: 1. The influence of uplift rate on the sediment flux. 2. The delayed response of the system to perturbation and thus the importance of catchment history