Chapter

Modelling Water and Tillage Erosion using Spatially Distributed Models

DOI: 10.1007/3-540-36606-7_6

ABSTRACT Soil erosion models are valuable tools for understanding sedimentary records. In this paper, the potential use of a topography-based
model (WaTEM) for simulating long-term soil erosion and its effect of soil properties is discussed. Long-term (derived from
profile truncation) and medium-term (derived from 137Cs measurements) erosion patterns are compared with simulated patterns of water and tillage erosion. Results showed that WaTEM
is able to describe to reproduce the observed spatial pattern of long-term water erosion reasonably well. However, the 137Cs data indicated that a major change in erosion and sedimentation patterns has occurred over the last decades: the dominance
of water erosion over a time scale of several thousands of years explains the spatial pattern of soil truncation. On the other
hand, the 137Cs data indicate that the present-day pattern of soil erosion is dominated by tillage. WaTEM is also used to assess the effect
of changes in landscape structure on soil erosion. It was shown that, when shifting focus from the field to the catchment
scale, the way we represent space in distributed models affects the model performance at least as dramatically as the physical
description of the process. Finally, a model application whereby WaTEM is linked with a mass-balance model, showed that simulating
the effects of soil erosion on the redistribution of soil properties is an important issue when trying to link surface processes
and sedimentary records.

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