Datensatz

Zusammenfassung

MEFIDIS–short for Physically Based Distributed Erosion Model–was developed to simulate the
consequences of climate and land-use changes for surface runoff and erosion patterns during extreme
rainfall events. The model relies on physically based runoff and soil detachment equations, dividing
the simulation area into spatial homogeneous units and using a dynamic approach for runoff and
suspended sediment distribution. It was evaluated with measured runoff and net erosion data for 16
events in the Lucky Hills 103 (USA) and Ganspoel (Belgium) catchments, using a single parameter
set for each catchment and simple assumptions (wet or dry) on pre-storm soil moisture. The model
was applied with a resolution of 55 m and 1-s time-steps. Observed soil erosion patterns in
Ganspoel were also used in the evaluation exercise.
Overall, simulation results have a good correlation with measured data (ranging from 0.85 to
0.96). Model precision was less satisfactory (average unsigned error ranging from 37% to 47%),
but it still fell well below the variability of the events (two orders of magnitude for runoff and
net erosion). Part of the simulation errors appear to be linked with variability in runoff and
erosion measurements. The calibrated model for Ganspoel required two parameter sets for
crusted and non-crusted conditions for half of the analyzed land-use classes; better calibration of
parameters associated with crusting significantly improved model performance for this
catchment. Despite this problem, MEFIDIS was shown to perform well for the range of
selected events.