Hillslope and point based soil erosion – an evaluation of a Landscape Evolution Model. Issue 5 (4th February 2019)

• Record Type: Journal Article
• Authors: Hancock, G.R.; Wells, T.; Dever, C.; Braggins, M.
• Is Part Of: Earth surface processes and landforms. Volume 44:Issue 5(2019)
• Page Start: 1163
• Page End: 1177
• Publication Date: 2019-02-04
• Subjects: soil erosion -- SIBERIA -- 137Cs -- landscape evolution model -- sediment transport; Geomorphology -- Periodicals; 551.4
• DOI: 10.1002/esp.4566
• Languages: English
• ISSNs: 0197-9337

Abstract

Abstract: Excessive soil erosion and deposition is recognised as a significant land degradation issue. Quantifying soil erosion and deposition is a non‐trivial task. One of these methods has been the mathematical modelling of soil erosion and deposition patterns and the processes that drive them. Here we examine the capability of a landscape evolution model to predict both soil erosion rate and pattern of erosion and deposition. This numerical model (SIBERIA) uses a Digital Elevation Model (DEM) to represent the landscape and calculates erosion and deposition at each grid point in the DEM. To assess field soil redistribution rates (SRR) and patterns the distribution of the environmental tracer 137 Cs has been analysed. Net hill slope SRR predicted by SIBERIA (a soil loss rate of 1.7 to 4.3 t ha ‐1 yr ‐1 ) were found to be in good agreement with 137 Cs based estimates (2.1 – 3.4 t ha ‐1 yr ‐1 ) providing confidence in the predictive ability of the model at the hillslope scale. However some differences in predicted erosion/deposition patterns were noted due to historical changes in landscape form (i.e. the addition of a contour bank) and possible causes discussed, as is the finding that soil erosion rates are an order of magnitude higher than likely soil production rates. The finding that SIBERIA can approximate independently quantified erosion and deposition patterns and rates is encouraging, providing confidence in the employment of DEM based models to quantify hillslope erosion rates and demonstrating the potential to upscale for the prediction of whole catchment erosion and deposition. The findings of this study suggest that LEMs can be a reliable alternative to complex and time consuming methods such as that using environmental tracers for the determination of erosion rates. The model and approach demonstrates a new approach to assessing soil erosion that can be employed elsewhere. © 2018 John Wiley & Sons, Ltd. Abstract : We examine the capability of a landscape evolution model (LEM) to predict both soil erosion rate and pattern of erosion and deposition. The outputs from this numerical model (SIBERIA) was compared to field measured soil redistribution rates and patterns determined using the environmental tracer 137 Cs. SIBERIA can approximate these independently quantified erosion and deposition patterns and rates suggesting that LEMs can be a reliable alternative to complex and time consuming methods such as that using environmental tracers for the determination of erosion rates.