Distributed Modeling of Soil Erosion and Deposition Affected by Buffer Strips.

Distributed modeling of soil erosion and deposition affected by buffer strips

Ataallah Khademalrasoul[1], Goswin Heckrath[2], Bo V. Iversen[3], Daniel Fischlewitz[4], Søren E. Larsen[5] and Brian Kronvang[6]

Soil degradation and environmental impacts due to water erosion are a growing concern globally. Large parts of Denmark are covered by gently rolling moraine landscape with moderately to locally highly erodible soils where water erosion causes off-site problems in the form of eutrophication of water bodies. Buffer zones can be efficient in terms of retaining sediment and phosphorus transported by water erosion. This study aimed at parameterizing a spatial distributed erosion model to evaluate the effect of different buffer zone properties and dimension. It was our hypothesis that the placement and dimension of buffer zones in the landscape can be optimized by means of spatially distributed erosion and deposition modeling. During the period from 1998 to 2000 field campaigns were done on a range of agricultural land in Denmark. On 21 slope units and adjacent buffer zones, rill erosion and deposition was surveyed during the runoff season. In addition, organic carbon and phosphorous contents as well as bulk density were determined in soils of eroding and depositional sites. General buffer zone properties were recorded. Here we present results from scenario analyses comparing measured sediment deposition and discharge to streams with predictions obtained with the distributed soil erosion and deposition model WaTEM and assess the potential of using such tool to assist with the planning of buffer zones in landscapes.

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[1] PhD student of Aarhus university, Department of Agroecology- Ataalah.khademalrasoul@agrsci.dk -Blichers Allé 20, Postbox 50 DK-8830 Tjele

[2] Associate Professor of Aarhus university, Department of Agroecology

[3] Associate Professor of Aarhus university, Department of Agroecology

[4] Physical Geography and Environmental change  Department of Environmental sciences university of Basel, Switzerland

[5]^,6 Aarhus University Bioscience, Vejlsøvej 25, 8600 Silkeborg