Chapter 11
Detecting Fingerprints of Gravity
Erosion Drivers: A Laboratory
Experiment
Abstract The morphology of the failure scar has been a long-debated issue concerning the Loess Plateau of China, and the lack of normative data has hampered
vital research in this area. In this chapter, a series of laboratory experiments were
conducted to observe the failure geometries and volumes under rainfall simulations.
The following six failure-scar types occurred: Tf, Cd, Cu, Ia, Ps, and Co. Tf, Cd, and
Cu were the three major types of failure scars during the process of gravity erosion on
a steep loess slope, and the scar Tf was the most significant. A relatively dangerous
failure scar (Tf) might appear if the slope became steeper, or if the rainfall became
more intensive. In addition, a long-duration storm could easily induce a large-volume
failure with a Cu scar. The experimental results obtained here provide a morphogenic
insight into the gravity-erosion control on a loess gully sidewall.
Keywords Loess Plateau · Gravity erosion · Failure scar · Rainfall · Topography
11.1 A Retrospective Study on the Failure Scar on the Slope
A failure scar is a crucial morphological characteristic for the reason that it can be
regarded as a fingerprint to reflect the stability of a slope, the method of failure
triggering, and the frequency and size of the gravity erosion. Previous papers (e.g.,
Zhang et al. 1997) reported that the failure scar could directly reflect the size of gravity
erosion. Moreover, different morphologies of scars will correspond to distinct failure
mechanisms (Millar and Quick 1997). Consequently, determining the morphologies
of the scars is a key step for conserving soil and water and assessing the efficacy of
gravity erosion treatment.
Gravity erosion, also called mass movement, mass wasting, slope movement, and
slope failure (Blaschke et al. 2000), is the mass failure triggered by self-weight (Xu
et al. 2015a) and is prone to occur on steep slopes (Xu et al. 2015b; Krohn et al. 2014;
Basharat et al. 2014). Mass failures which are induced by rainfall frequently occur
on the Loess Plateau because the area is characterized by complex topography of
crisscrossing gullies having fragmentized terrain surface and extremely steep slope
(Qiu et al. 2017). Numerous studies have suggested that the contribution of the
mass failure to soil loss on the Loess Plateau is remarkable (Chen et al. 2007) and
© Science Press and Springer Nature Singapore Pte Ltd. 2020
X. Xu et al., Experimental Erosion,
https://doi.org/10.1007/978-981-15-3801-8_11
169
Detecting Fingerprints of Gravity
Erosion Drivers: A Laboratory
Experiment
Abstract The morphology of the failure scar has been a long-debated issue concerning the Loess Plateau of China, and the lack of normative data has hampered
vital research in this area. In this chapter, a series of laboratory experiments were
conducted to observe the failure geometries and volumes under rainfall simulations.
The following six failure-scar types occurred: Tf, Cd, Cu, Ia, Ps, and Co. Tf, Cd, and
Cu were the three major types of failure scars during the process of gravity erosion on
a steep loess slope, and the scar Tf was the most significant. A relatively dangerous
failure scar (Tf) might appear if the slope became steeper, or if the rainfall became
more intensive. In addition, a long-duration storm could easily induce a large-volume
failure with a Cu scar. The experimental results obtained here provide a morphogenic
insight into the gravity-erosion control on a loess gully sidewall.
Keywords Loess Plateau · Gravity erosion · Failure scar · Rainfall · Topography
11.1 A Retrospective Study on the Failure Scar on the Slope
A failure scar is a crucial morphological characteristic for the reason that it can be
regarded as a fingerprint to reflect the stability of a slope, the method of failure
triggering, and the frequency and size of the gravity erosion. Previous papers (e.g.,
Zhang et al. 1997) reported that the failure scar could directly reflect the size of gravity
erosion. Moreover, different morphologies of scars will correspond to distinct failure
mechanisms (Millar and Quick 1997). Consequently, determining the morphologies
of the scars is a key step for conserving soil and water and assessing the efficacy of
gravity erosion treatment.
Gravity erosion, also called mass movement, mass wasting, slope movement, and
slope failure (Blaschke et al. 2000), is the mass failure triggered by self-weight (Xu
et al. 2015a) and is prone to occur on steep slopes (Xu et al. 2015b; Krohn et al. 2014;
Basharat et al. 2014). Mass failures which are induced by rainfall frequently occur
on the Loess Plateau because the area is characterized by complex topography of
crisscrossing gullies having fragmentized terrain surface and extremely steep slope
(Qiu et al. 2017). Numerous studies have suggested that the contribution of the
mass failure to soil loss on the Loess Plateau is remarkable (Chen et al. 2007) and
© Science Press and Springer Nature Singapore Pte Ltd. 2020
X. Xu et al., Experimental Erosion,
https://doi.org/10.1007/978-981-15-3801-8_11
169