Stefan Wirtz Vom Fachbereich VI (Geographie/Geowissenschaften ...

Experimentelle Rinnenerosionsforschung vs. Modellkonzepte – Quantifizierung der hydraulischen und erosiven Wirksamkeit von Rinnen
Fig. 6: Results RE Belerda
Discussion
The estimation of the contributing areas for the experimental runoff shows that these are
considerably smaller than the catchments of the rills. This leads to the conclusion that the
runoff used within these experiments represents a low magnitude-high frequency event.
Therefore, the measured amounts of erosion and hydraulic dynamic have to be valued as low.
This should be remembered when considering or comparing sediment concentrations.
The sediment concentrations measured in our experiments are interesting and important when
compared with previous experiments. Polyakov and Nearing (2003) tested, in laboratory
experiments, the behaviour of rills in al loamy substrate under different inflow quantities (6
and 9 L min -1 ) and rill lengths. The sediment concentrations in their experiment reached
values between 10 and 130 g L -1 . Loch (2000) tested the influence of vegetation on soil
erosion. In one of his plots, both inter-rill and rill erosion were observed. The sediment
concentrations of this plot reached a maximum value of 210 g L -1 . The maximum value
measured in our rill experiments in Andalusia was 437.6 g L -1 , which is about double the
maximum value in the experiments of Loch (2000) and about 3.5 times higher than the values
in the laboratory experiments of Polyakov and Nearing (2003). This is remarkable because, in
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