Landslide Susceptibility Assessment using Distributed Hydrological Modeling and Slope Stability Analysis
Abstract
Rainfall-induced shallow landslides pose a serious danger to human life and property. Hence the ability to determine storm event-induced landslide susceptibility is crucial for early warning to reduce the casualties. We present a physical-based landslide detection approach that combines an integrated physical-based distributed hydrological model (ParFlow-CLM), with slope stability analysis. ParFlow-CLM was selected for its ability to model complex saturated and unsaturated flow processes, surface-subsurface interactions and spatial-temporal variability. Using the simulated soil saturation from ParFlow-CLM, the slope safety factor was determined by taking into account suction stress hysteresis in the unsaturated zone as well as variations in soil properties across depth.
The proposed approach was applied on a case study from a recorded storm-induced landslide in Liugui, a rural district in southern Taiwan. Results show that the lowest safety factor does not occur at the top layer of the model but some distance below the ground surface. In addition, when the groundwater table is initially deep, a low intensity rain event can increase the safety factor of the middle layer in the soil zone (about one meter below ground surface). However, a long duration and heavy rain intensity event will cause the layer to become unstable when the soil layer is close to saturation. Comparing against the actual reported landslide events in Liugui, the model was able to predict the location and timing of the events with a reasonable accuracy.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMNH33D0945J
- Keywords:
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- 1810 Debris flow and landslides;
- HYDROLOGY;
- 1826 Geomorphology: hillslope;
- HYDROLOGY;
- 4306 Multihazards;
- NATURAL HAZARDS;
- 7212 Earthquake ground motions and engineering seismology;
- SEISMOLOGY