Predicting uncertainty in sediment transport and landscape evolution - the influence of initial surface conditions

Hancock, G. R.; Coulthard, T. J.; Lowry, J. B. C.

Abstract

© 2015. Numerical landscape evolution models were initially developed to examine natural catchment hydrology and geomorphology and have become a common tool to examine geomorphic behaviour over a range of time and space scales. These models all use a digital elevation model (DEM) as a representation of the landscape surface and a significant issue is the quality and resolution of this surface. Here we focus on how subtle perturbations or roughness on the DEM surface can produce alternative model results. This study is carried out by randomly varying the elevations of the DEM surface and examining the effect on sediment transport rates and geomorphology for a proposed rehabilitation design for a post-mining landscape using multiple landscape realisations with increasing magnitudes of random changes. We show that an increasing magnitude of random surface variability does not appear to have any significant effect on sediment transport over millennial time scales. However, the random surface variability greatly changes the temporal pattern or delivery of sediment output. A significant finding is that all simulations at the end of the 10,000 year modelled period are geomorphologically similar and present a geomorphological equifinality. However, the individual patterns of erosion and deposition were different for repeat simulations with a different sequence of random perturbations. The alternative positions of random perturbations strongly influence local patterns of hillslope erosion and evolution together with the pattern and behaviour of deposition. The findings demonstrate the complex feedbacks that occur even within a simple modelled system.

Citation

Hancock, G. R., Coulthard, T. J., & Lowry, J. B. C. (2016). Predicting uncertainty in sediment transport and landscape evolution - the influence of initial surface conditions. Computers & geosciences, 90(B), 117-130. https://doi.org/10.1016/j.cageo.2015.08.014

• Journal Article Type: Article
• Acceptance Date: Aug 31, 2015
• Online Publication Date: Sep 16, 2015
• Publication Date: 2016-05
• Deposit Date: Oct 28, 2015
• Publicly Available Date: Nov 23, 2017
• Journal: Computers & geosciences
• Print ISSN: 0098-3004
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 90
• Issue: B
• Pages: 117-130
• DOI: https://doi.org/10.1016/j.cageo.2015.08.014
• Keywords: Sediment transport, Equifinality, Soil erosion modelling, SIBERIA, Statistical uncertainty, Mine rehabilitation
• Public URL: https://hull-repository.worktribe.com/output/380407
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0098300415300406
• Additional Information: Authors' accepted manuscript of article published in: Computers & geosciences, 2016, v.90 part B.