10.4 Results and Discussion
165
on the original data obtained in the laboratory or field. An in-depth qualitative review
of the erosion rule will give great help to the test design and sensitivity analysis.
Vegetation also appeared to play a distinct role in controlling the locations of
landslides at this site (Shakoor and Smithmyer 2005). In the vegetated areas, plant
roots acted as a binder adding to soil strength, and thus reinforcing soils and improving their stability on slopes (Easson and Yarbrough 2002; Shields and Gray 1992;
Waldron and Dakessian 1981). Thus experiments on the landform with different vegetation covers are expected in the future. Finally, the mechanical properties of soil,
such as cohesion, friction angle, and density play an immediate role in the interpretation of mass failure behavior. Thus, a sensitivity analysis was also worth performing
to evaluate variations in the factor of safety with respect to changes in the above
mechanical parameters.
10.5 Conclusions
The experimental results obtained here provide insights into the pre-failure mechanisms and erosion processes of steep loess slopes. In an event of rainfall, various
types of gravity erosion might emerge in the same period, and mass failures with
the same mode and similar size often appeared adjacently in the same run of rainfall. Compound landslide, a group of mass failures might happen on a large slowly
slipping block, was also observed in the tests.
Climate-driven factors and topography triggers had prominent influences on gravity erosion. Whether for the total amount or the peak amount in an experiment, the
largest sensitivity parameter on both the landslide and mudslide was that of rainfall
duration. In comparison, topography was relatively less influential. The sensitivity
parameter of the slope gradient was the highest influence on the avalanche for the
peak of an individual event.
References
Acharya G, Cochrane T, Davies T, et al. 2011. Quantifying and modeling post-failure sediment
yields from laboratory-scale soil erosion and shallow landslide experiments with silty loess.
Geomorphology, 129(1–2): 49–58.
Ali A, Huang J S, Lyamin A V, et al. 2014. Boundary effects of rainfall-induced landslides.
Computers and Geotechnics, 61: 341–354.
Au S W C. 1998. Rain-induced slope instability in Hong Kong. Engineering Geology, 51(1): 1–36.
Benda L, Dunne T. 1997. Stochastic forcing of sediment supply to channel networks from landsliding
and debris flow. Water Resources Research, 33(12): 2849–2863.
Cao Y Z. 1981. Mechanism and prediction of the gravity erosion on the loess area. Bulletin of Soil
and Water Conservation, (4): 19–23 (in Chinese).
Easson G, Yarbrough L D. 2002. The effects of riparian vegetation on bank stability. Environmental
and Engineering Geoscience, 8(4): 247–260.
165
on the original data obtained in the laboratory or field. An in-depth qualitative review
of the erosion rule will give great help to the test design and sensitivity analysis.
Vegetation also appeared to play a distinct role in controlling the locations of
landslides at this site (Shakoor and Smithmyer 2005). In the vegetated areas, plant
roots acted as a binder adding to soil strength, and thus reinforcing soils and improving their stability on slopes (Easson and Yarbrough 2002; Shields and Gray 1992;
Waldron and Dakessian 1981). Thus experiments on the landform with different vegetation covers are expected in the future. Finally, the mechanical properties of soil,
such as cohesion, friction angle, and density play an immediate role in the interpretation of mass failure behavior. Thus, a sensitivity analysis was also worth performing
to evaluate variations in the factor of safety with respect to changes in the above
mechanical parameters.
10.5 Conclusions
The experimental results obtained here provide insights into the pre-failure mechanisms and erosion processes of steep loess slopes. In an event of rainfall, various
types of gravity erosion might emerge in the same period, and mass failures with
the same mode and similar size often appeared adjacently in the same run of rainfall. Compound landslide, a group of mass failures might happen on a large slowly
slipping block, was also observed in the tests.
Climate-driven factors and topography triggers had prominent influences on gravity erosion. Whether for the total amount or the peak amount in an experiment, the
largest sensitivity parameter on both the landslide and mudslide was that of rainfall
duration. In comparison, topography was relatively less influential. The sensitivity
parameter of the slope gradient was the highest influence on the avalanche for the
peak of an individual event.
References
Acharya G, Cochrane T, Davies T, et al. 2011. Quantifying and modeling post-failure sediment
yields from laboratory-scale soil erosion and shallow landslide experiments with silty loess.
Geomorphology, 129(1–2): 49–58.
Ali A, Huang J S, Lyamin A V, et al. 2014. Boundary effects of rainfall-induced landslides.
Computers and Geotechnics, 61: 341–354.
Au S W C. 1998. Rain-induced slope instability in Hong Kong. Engineering Geology, 51(1): 1–36.
Benda L, Dunne T. 1997. Stochastic forcing of sediment supply to channel networks from landsliding
and debris flow. Water Resources Research, 33(12): 2849–2863.
Cao Y Z. 1981. Mechanism and prediction of the gravity erosion on the loess area. Bulletin of Soil
and Water Conservation, (4): 19–23 (in Chinese).
Easson G, Yarbrough L D. 2002. The effects of riparian vegetation on bank stability. Environmental
and Engineering Geoscience, 8(4): 247–260.