Landslide Susceptibility
Where slopes are prone to fail, from slope, rock, heavy rain, earthquake shaking and structures.
Draw an area and the tool ranks the ground from very low to very high susceptibility to landslides from nine evidence layers: slope, rock and soil type, the heavy-rain day, the strongest earthquake shaking on record, distance to lineaments, distance to streams, plan curvature, vegetation and land cover. The layers are weighted by the analytic hierarchy process and the map is checked against mapped landslides.
Overview
A landslide needs a weak, steep slope and a trigger. The conditioning layers (slope, rock type, structures, stream undercutting, landform and cover) describe how prone each slope is; the triggering layers (the wettest day of the year and the strongest earthquake shaking recorded nearby) describe how hard it is pushed. Each is rated 1–5 and combined with weights from the pairwise comparisons of the analytic hierarchy process.
Shaking is computed from every recorded earthquake of magnitude 4 or more within about 200 km, with the attenuation relation of Joyner and Boore (1981), and each cell keeps the strongest value. Heavy rain is the ten-year mean of each year’s wettest day. The result shows where slopes are prone to fail, not when; it guides land-use planning, slope investigation and field checks after storms and earthquakes.
What you enter · What you get
What you enter
- Area of study (4–2500 km²)
- Imagery year
- Importance of each layer (1–9)
- Your lineaments (GeoJSON, optional)
- Mapped landslides (CSV or tapped, optional)
What you get
- Susceptibility map in five classes with areas
- Every layer as values and ratings
- AHP weights with the consistency ratio
- Success-rate and ROC curves, frequency ratios
- Framed map sheet, layer figure, ASCII grid, CSV
How it works in the field
Method and equations
Ratings
Slope < 5°, 5–15°, 15–25°, 25–35°, > 35° → 1, 2, 4, 5, 5. Heavy-rain day 20 / 35 / 50 / 75 mm. Peak ground acceleration 0.05 / 0.1 / 0.2 / 0.35 g. Distance to lineaments 250 / 500 / 1000 / 2000 m; to streams 100 / 250 / 500 / 1000 m. Plan curvature by fifths of the area: the most concave fifth 5, the next 4, the middle 1, the convex fifths 2 and 3.
Earthquake shaking
Peak ground acceleration from each recorded event, the largest kept per cell.
Plan curvature
Zevenbergen–Thorne curvature across the slope, in 1/100 m; negative where contours bend into a hollow and flow converges.
Analytic hierarchy process
Saaty pairwise matrix from the importance scores, principal eigenvector, CR < 0.10; the index is classed by natural breaks.
Accuracy and error limits
- The map ranks relative susceptibility, not probability or timing; tested on mapped landslides, models of this kind reach success-curve areas of 0.7–0.85. Slope from a 30 m model underestimates short steep slopes.
- Rock and soil types come from regional maps, and weights from expert judgement; road cuts, irrigation and quarrying, common triggers, are not represented.
- To reduce the error: map past landslides from imagery and in the field to validate the map, test other weights, and assess individual slopes with the Slope Stability tool.
Who uses it
Standards and references
- Varnes, D.J. (1984). Landslide Hazard Zonation: A Review of Principles and Practice. UNESCO, Paris.
- Guzzetti, F., Carrara, A., Cardinali, M. & Reichenbach, P. (1999). Landslide hazard evaluation: a review of current techniques and their application in a multi-scale study, Central Italy. Geomorphology, 31, 181–216.
- Reichenbach, P., Rossi, M., Malamud, B.D., Mihir, M. & Guzzetti, F. (2018). A review of statistically-based landslide susceptibility models. Earth-Science Reviews, 180, 60–91.
- Kirschbaum, D. & Stanley, T. (2018). Satellite-based assessment of rainfall-triggered landslide hazard for situational awareness. Earth’s Future, 6, 505–523.
- Joyner, W.B. & Boore, D.M. (1981). Peak horizontal acceleration and velocity from strong-motion records including records from the 1979 Imperial Valley, California, earthquake. BSSA, 71(6), 2011–2038.
- Keefer, D.K. (1984). Landslides caused by earthquakes. GSA Bulletin, 95, 406–421.
- Zevenbergen, L.W. & Thorne, C.R. (1987). Quantitative analysis of land surface topography. Earth Surface Processes and Landforms, 12, 47–56.
- Saaty, T.L. (1980). The Analytic Hierarchy Process. McGraw-Hill, New York.
- Copernicus DEM GLO-30, Copernicus Sentinel-2 Level-2A, ESA WorldCover 10 m, USGS earthquake catalogue, Macrostrat geological map (CC BY 4.0).
At a glance
- Category
- Natural hazards
- Runs on
- Phone, tablet and desktop browser
- Export
- Map sheet PNG, layer figure PNG, ASCII grid, CSV, PDF report
- Access
- Subscribers
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