r.rotstab: a GRASS-based deterministic model for deep-seated - - PowerPoint PPT Presentation
r.rotstab: a GRASS-based deterministic model for deep-seated landslide susceptibility over large areas Martin Mergili 1 , Ivan Marchesini 2 , Mauro Rossi 2 , Fausto Guzzetti 2 , Wolfgang Fellin 3 1 Institute of Applied Geology, BOKU University,
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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1 Institute of Applied Geology, BOKU University, Vienna, Austria 2 CNR IRPI, Perugia Italy 3 Geotechnical and Tunnel Engineering, University of Innsbruck, Austria
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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FSinf > 1: slope is stable FSinf < 1: slope is not stable
FS inf = R T = c/cos β+N tan ϕ T
γw θs d normal force N =G'cos β c shear force T =G'sin β+S shear resistance R=N tan ϕ+c/cos β β
buoyancy
weight of moist soil
G'=γd d+θs γw d sub−γw d sub ....=γd d+(θs−1)γwd sub
seepage force S=γw d subsin β φ γd
γd ... specific weight of dry soil (N/m³) γw ... specific weight of water (N/m³) c ... cohesion soil + roots (N/m²) φ ... angle of internal friction (°) θs ... sat. water content (vol.-%)
dsub
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
4 Photo: USGS
shallow translational failure deep-seated rotational failure The infinite slope stability model is only applicable to shallow translational slides in cohesionless regolith. It shall not be used for modelling of rotational slope failures and deep-seated mass movements
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
forces are shown for every second column only
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slip circle inter-column forces
Bishop (1954), Janbu et al. (1956), Hovland (1977)
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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3 2 1
1 FS = 1.83 2 FS = 1.16 3 FS = 0.67 application with GIS non-trivial no pixel-based approach 1 FS = 0.67
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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www.clara-w.com (Hungr, 1988)
Xie et al. (2003, 2004a, b, 2006), Marchesini et al. (2009)
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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GRASS GIS
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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data input data preprocessing post-processing of results display and export of results start of simulation shell script r.rotstab.sh with terminal interface run within GRASS GIS simulation C code r.rotstab GRASS raster module
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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possible slip surface geometries
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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a c x' z' = z z'' a b x y x' y'
d i r e c t i
s t e e p e s t s l
e
(a) ground plot (b) longi- tudinal section along x' α β zb L D r·a r·a r·a r·a P1 P2 P1‘ P2‘ x''
parameters randomization of center coordinates, a, b, c, zb and r
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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forces are shown for every second column only
inter-column forces are neglected (Fellenius appoach) sum of stabilizing and destabilizing forces over all columns
modified after Hovland, 1977, Xie et al., 2003, 2004a, b, 2006
FS 3D=∑C (cA+(G 'cos βm+N s) tan ϕ)cos βm
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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bedrock
minimum FS and depth of slip surface if FS < 1 are determined for each raster cell test of many randomly selected slip surfaces
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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random ellipsoid critical slip surface? R T G‘, S γd, c, φ, θs, geometry ellipsoid parameters
slip surface
depth of slip surface factor of safety FS3D
column 1
factor of safety raster cell level input ellipsoid level slip surface level column level R T G‘, S
column 2
columns depth of slip surface factor of safety minimum factor of safety FS3D deepest slip surface with FS3D < 1
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Hungr et al., 1989 Lam and Fredlund, 1993 Xie et al., 2006 Leshchinsky et al., 1985 Hungr et al., 1989 Xie et al, 2006 Xie et al, 2006 and others
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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cell size / model (a) (b) with C1 (b) with C2 cell size (c) slip surface 1 with / without weak layer (c) slip surface 2 dry (c) slip surface moist Results with r.rotstab (version with Hovland 3D model) 0.02 m 1.43 1.19 1.28 0.5 m 2.03 / 2.02 1.58 1.53 0.05 m 1.38 1.18 1.27 1.0 m 2.10 / 2.05 1.58 1.53 0.10 m 1.35 1.16 1.26 2.0 m 2.04 / 2.02 1.53 1.48 Results with 3DSlopeGIS (Xie et al., 2006) Hovland 3D 1.43 1.19 1.25 2.09 1.57 1.49 Bishop 3D 1.43 1.20 1.31 2.28 1.71 1.62 Janbu 3D 1.40 1.22 1.29 2.04 1.61 1.54 Revised Hovland 3D 1.38 1.18 1.27 2.30 1.67 1.57
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Class γd kN m-3 c (d = 1.3 m) kN m-2 c (d = 20 m) kN m-2 φ° θs vol.-% c90 c95 c98 c90 c95 c98 Sand 19 0.5* 0.5* 0.5* 4.0* 4.0* 4.0* 38 40 Clay 22 0.0 1.8 4.5 0.0 15.5 40.0 18 45 Flysch deposit 18 1.8 3.1 4.8 16.0 27.5 44.0 15 45 Gravel, sand, silt and clay 19 1.5* 1.5* 1.5* 13.0* 13.0* 13.0* 30 45 Sand, silt and clay 18 0.9 2.5 4.6 7.5 21.5 42.0 15 45 Sandstone 22 0.0 2.1 4.0 0.0 16.0 34.0 35 45 Conglomerate 22 1.0* 1.0* 2.1 8.5* 8.5* 17.0 35 45 Limestone 22 1.5* 1.5* 1.5* 13.0* 13.0* 13.0* 35 45 Travertine 22 1.0* 1.0* 1.0* 8.5* 8.5* 8.5* 35 45 saturated water content Angle of internal friction cohesion dry specific weight
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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True positive (TP): cell predicted as unstable (FS<1) and that contains a landslide, True negative (TN): cell predicted as stable (FS>=1) that does not contain a landslide, False positive (FP): cell predicted as unstable (FS<1) that does not contain a landslide, False negative (FN): cell predicted as stable (FS>=1) that contains a landslide.
TP TN FP FN Four-fold-plots TP TN FP FN TP TN FP FN
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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True positive (TP): cell predicted as unstable (FS<1) and that contains a landslide, True negative (TN): cell predicted as stable (FS>=1) that does not contain a landslide, False positive (FP): cell predicted as unstable (FS<1) that does not contain a landslide, False negative (FN): cell predicted as stable (FS>=1) that contains a landslide.
TP TN FP FN Four-fold-plots TP TN FP FN TP TN FP FN
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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True positive (TP): cell predicted as unstable (FS<1) and that contains a landslide, True negative (TN): cell predicted as stable (FS>=1) that does not contain a landslide, False positive (FP): cell predicted as unstable (FS<1) that does not contain a landslide, False negative (FN): cell predicted as stable (FS>=1) that contains a landslide.
TP TN FP FN Four-fold-plots TP TN FP FN TP TN FP FN
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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TN FP FN
Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Bishop, A.W., 1954. The use of the slip circle in the stability analysis of slopes. Geotechnique 5(1), 7–17. Griffiths, D.W., Huang, J., de Wolfe, G.F., 2011. Numerical and analytical observations on long and infinite slopes. International Journal for Numerical and Analytical Methods in Geomechanics 35, 569–585. Hovland, H.J., 1977. Three-dimensional slope stability analysis method. Journal of the Geotechnical Engineering Division. Proceedings of the American Society
Hungr, O., 1988. CLARA: slope stability analysis in two or three dimensions. O. Hungr Geotechnical Research, Vancouver, BC. Hungr, O., Salgado, F.M., Byrne, P.M., 1989. Evaluation of a three-dimensional method of slope stability analysis. Canadian Geotechnical Journal 26, 679–686. Janbu, N., Bjerrum, L., Kjaernsli, B., 1956. Soil mechanics applied to some engineering problems. Publication 16, Norwegian Geotechnical Institute, Oslo. Lam, L., Fredlund, D.G., 1993. A general limit equilibrium model for 3-D slope stability analysis. Canadian Geotechnical Journal 30, 905–919. Leshchinsky, D., Baker, R., Silver, M.L., 1985. Three-dimensional analysis of slope stability. International Journal of Numerical and Analytical Methods in Geomechanics 9, 199–223. Marchesini, I., Cencetti, C., De Rosa, P., 2009. A preliminary method for the evaluation of the landslides volume at a regional scale. Geoinformatica 13, 277–289. Milledge, D., Griffiths, V., Warburton, J., Lane, S., 2011. Can we use the infinite slope model within catchment scale landslide models given its landslide length assumption? Geophysical Research Abstracts 13, EGU2011–3127. Xie, M., Esaki, T., Zhou, G., Mitani, Y., 2003. Three-dimensional stability evaluation of landslides and a sliding process simulation using a new geographic information systems component. Environmental Geology 43, 503–512. Xie, M., Esaki, Cai, M., 2004a. A GIS-based method for locating the critical 3D slip surface in a slope. Computers and Geotechnics 31, 267–277. Xie, M., Esaki, T., Zhou, G., 2004b. GIS-based Probabilistic Mapping of Landslide Hazard Using a Three-Dimensional Deterministic Model. Natural Hazards 33, 265–282. Xie, M., Esaki, T., Qiu, C., Wang, C., 2006. Geographical information system-based computational implementation and application of spatial three-dimensional slope stability analysis. Computers and Geotechnics 33, 260–274.
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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Presentation OGRS 2012 Yverdon, October 2012 r.rotstab: a GRASS-based deterministic model for landslide susceptibility analysis
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