Abstract
Hillslope and catchment evolution will be the cumulative product of
short and long-term processes that operate and dominate over different
hillslope length scales. In this study erosion and deposition patterns
rates generated over short lengths scales (0.1-3m) are examined using
erosion pins over a 14 year period for a field site in northern
Australia. The pins consisted of two sets of nine pins located on a
catchment divide. Over the 14 year period, there was considerable
variability in erosion and deposition with both sites being depositional
(~7mm of deposition). The sites, separated by several
hundred metres both had very similar erosion and deposition patterns.
Annual erosion and deposition patterns were modelled using a computer
based Landscape Evolution Model (SSSPAM) that models both fluvial and
diffusive erosion. Model results found that SSSPAM was unable to predict
the erosion and deposition rate and patterns using a Digital Elevation
Model (DEM) for the site. However, when the DEM was modified at each
annual time step to capture short length scale random particle movement,
SSSPAM predicted both erosion and deposition variability as well as the
field measured deposition. The model results demonstrate that the
commonly used equation for diffusion when calibrated for the site
performs well.