Integration of root systems into a GIS-based slip surface model: computational experiments in a generic hillslope environment

Author(s)
Elmar Schmaltz, Martin Mergili
Abstract

Integration of root systems into a GIS-based slip surface model: computational experiments in a generic hillslope environment Abstract Root systems of trees reinforce the underlying soil in hillslope environments and therefore potentially increase slope stability. So far, the influence of root systems is disregarded in Geographic Information System (GIS) models that calculate slope stability along distinct failure plane. In this study, we analyse the impact of different root system compositions and densities on slope stability conditions computed by a GIS-based slip surface model. We apply the 2.5D slip surface model r.slope.stability to 23 root system scenarios imposed on pyramidoid-shaped elements of a generic landscape. Shallow, taproot and mixed root systems are approximated by paraboloids and different stand and patch densities are considered. The slope failure probability (P f) is derived for each raster cell of the generic landscape, considering the reinforcement through root cohesion. Average and standard deviation of P f are analysed for each scenario. As expected, the r.slope.stability yields the highest values of P f for the scenario without roots. In contrast, homogeneous stands with taproot or mixed root systems yield the lowest values of P f. P f generally decreases with increasing stand density, whereby stand density appears to exert a more pronounced influence on P f than patch density. For patchy stands, P f increases with a decreasing size of the tested slip surfaces. The patterns yielded by the computational experiments are largely in line with the results of previous studies. This approach provides an innovative and simple strategy to approximate the additional cohesion supplied by root systems and thereby considers various compositions of forest stands in 2.5D slip surface models. Our findings will be useful for developing strategies towards appropriately parameterising root reinforcement in real-world slope stability modelling campaigns.

Organisation(s)
Department of Geography and Regional Research
Journal
Landslides
Volume
15
Pages
1561-1575
No. of pages
15
ISSN
1612-510X
DOI
https://doi.org/10.1007/s10346-018-0970-8
Publication date
2018
Peer reviewed
Yes
Austrian Fields of Science 2012
105404 Geomorphology
Keywords
ASJC Scopus subject areas
Geotechnical Engineering and Engineering Geology
Portal url
https://ucrisportal.univie.ac.at/en/publications/155cc563-46b6-4897-ba0a-633750d6c76d