scholarly journals Experimental Study on Landslides of Loose Sediment Slope Induced by Stream Bed Incision

2021 ◽  
Vol 9 ◽  
Author(s):  
Kehan Huang ◽  
Mengzhen Xu ◽  
Zhaoyin Wang
Keyword(s):  
Tibetan Plateau ◽  
Potential Energy ◽  
Bank Erosion ◽  
Critical Energy ◽  
Field Investigation ◽  
Flume Experiments ◽  
Loose Sediment ◽  
Scale Ratio ◽  
Landslide Body ◽  
Stream Bed

Uplift of the Qinghai-Tibetan Plateau has resulted in rapid incision of rivers along the margin of the plateau. Landslides occur frequently as a consequence of increasing bank slope and potential landslide energy due to stream bed incision or lateral bank erosion on the concave banks at bends. The Fencha Gully is on the eastern margin of the Qinghai-Tibetan Plateau and is developing on a huge landslide body. Flume experiments were conducted on the base of the field investigation to study the mechanism of landslides induced by stream bed incision. The experiments were designed with a length scale ratio of 1:20. Landslides and stream bed incision with loose sediment were observed and analyzed. The results show that landslides are induced as a result of stream bed incision. The potential landslide energy is defined, which increases quickly with an effective incision depth coupling vertical incision and lateral bank erosion. The occurrence of landslides can be attributed to increasing incision depth and potential landslide energy. Results indicate that the critical effective incision depth is 4.0–6.0 m. A critical value of the potential landslide energy is found from the experiments. Landslides occur if the potential energy exceeds the critical energy, which is 2.24×104 t·m/s2 for the Fencha Gully. The incision depth and potential energy of landslides from the Fencha Gully agree well with the results.

scholarly journals A theoretical model for the initiation of debris flow in unconsolidated soil under hydrodynamic conditions

2014 ◽  
Vol 2 (6) ◽  
pp. 4487-4524 ◽  
Author(s):  
C.-X. Guo ◽  
J.-W. Zhou ◽  
P. Cui ◽  
M.-H. Hao ◽  
F.-G. Xu
Keyword(s):  
Theoretical Model ◽  
Debris Flow ◽  
Surface Runoff ◽  
Slope Failure ◽  
Fine Particles ◽  
Field Investigation ◽  
Hydrodynamic Theory ◽  
Mechanism Analysis ◽  
Flume Experiments ◽  
Initiation Mechanism

Abstract. Debris flow is one of the catastrophic disasters in an earthquake-stricken area, and remains to be studied in depth. It is imperative to obtain an initiation mechanism and model of the debris flow, especially from unconsolidated soil. With flume experiments and field investigation on the Wenjiagou Gully debris flow induced from unconsolidated soil, it can be found that surface runoff can support the shear force along the slope and lead to soil strength decreasing, with fine particles migrating and forming a local relatively impermeable face. The surface runoff effect is the primary factor for accelerating the unconsolidated slope failure and initiating debris flow. Thus, a new theoretical model for the initiation of debris flow in unconsolidated soil was established by incorporating hydrodynamic theory and soil mechanics. This model was validated by a laboratory test and proved to be better suited for unconsolidated soil failure analysis. In addition, the mechanism analysis and the established model can provide a new direction and deeper understanding of debris flow initiation with unconsolidated soil.

scholarly journals A field investigation on debris flows in the incised Tongde sedimentary basin on the northeastern edge of the Tibetan Plateau

CATENA ◽  
2022 ◽  
Vol 208 ◽  
pp. 105727
Author(s):  
Liqun Lyu ◽  
Mengzhen Xu ◽  
Zhaoyin Wang ◽  
Yifei Cui ◽  
Koen Blanckaert
Keyword(s):  
Tibetan Plateau ◽  
Debris Flows ◽  
Sedimentary Basin ◽  
Field Investigation ◽  
The Tibetan Plateau

scholarly journals Sequence Analysis of Several Ancient River Blocking Events in the Suwalong Reach of the Upper Jinsha River Based on Multidisciplinary Approaches, SE Tibetan Plateau

2021 ◽  
Author(s):  
Yiwei Zhang ◽  
Jianping Chen ◽  
Qing Wang ◽  
Chun Tan ◽  
Yongchao Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Mass Movement ◽  
Field Investigation ◽  
Tibet Plateau ◽  
Tectonic Activity ◽  
The Tibetan Plateau ◽  
Jinsha River ◽  
Steep Terrain ◽  
Sbas Insar ◽  
Blocking Event

Abstract The temporary or permanent river blocking event caused by mass movement usually occurs on steep terrain. With the increase of mountain population and land use pressure and the construction of water conservancy and hydropower projects, river blocking event has gradually attracted people’s attention and understanding. The study area (Wangdalong-Gangda reach) is located in the upper reaches of the Jinsha River and the southeast edge of the Qinghai-Tibet Plateau. Affected by strong tectonic activity in the Jinsha River suture zone and the rapid uplift of the Tibetan Plateau, in the past 6000 years, there have been at least five obvious river blocking events in the reach of about 30 km in the study area. The number and density are very rare. Combined with the field investigation, indoor interpretation, laboratory tests, optically stimulated luminescence (OSL) dating, SBAS-InSAR and previous studies, multidisciplinary approaches are used to systematically summarize the analysis methods and further the understanding of one river blocking event and multiple river blocking events from difference perspectives. Especially in multiple river blocking events, we could get the wrong results, even the opposite conclusion if interaction is not considered. Through this study, the general method of analyzing the river blocking event and the problems that should be paid attention to in sampling are given, and relatively reliable historical results of river blocking events are obtained. This method has extensive applicability to the identification and analysis of river blocking events in other areas.

scholarly journals A regional model to predict the distribution patterns of alpine permafrost in the western part of the Qilianshan Mountains, on the northeastern edge of the Qinghai-Tibetan Plateau

2009 ◽  
Vol 6 (4) ◽  
pp. 5243-5278
Author(s):  
Y. Sheng ◽  
J. Li ◽  
J. Wu ◽  
B. Ye ◽  
J. Wang
Keyword(s):  
Spatial Distribution ◽  
Tibetan Plateau ◽  
Solar Radiation ◽  
Distribution Patterns ◽  
Field Investigation ◽  
Regional Model ◽  
Distribution Map ◽  
Frozen Ground ◽  
Ground Temperatures ◽  
Incoming Solar Radiation

Abstract. A field investigation and measurement of ground temperatures in boreholes was carried out in the upper area of Shule River in the western part of the Qilianshan Mountains, in the northeast of the Qinghai-Tibetan Plateau in 2008. On the basis of this a sketchy distribution pattern of permafrost in this area was established. A regional permafrost model considering the effects of latitude, altitude, slope and aspect on distribution of permafrost was developed. The effect of latitude was calculated by the Gauss curve as proposed by Cheng, and then added to the effect of altitude. A linear relationship was found between altitude and the measured ground temperatures. For the effects of slope and aspect which mainly affected the amount and spatial distribution of the incoming solar radiation, a linear equation based on increments of the incoming solar radiation and the changes in ground temperature was used to evaluate their influence on the development of permafrost. A distribution map of the frozen ground, as well as a classification map of permafrost based on ground temperatures was produced using the ARCGIS software. In addition, the spatial distribution patterns of frozen ground and each permafrost type in this region were also analyzed.

Centennial-scale process activity in a complex landslide body in the Qilian Mountains, northeast Tibetan Plateau, China

CATENA ◽  
2019 ◽  
Vol 179 ◽  
pp. 29-38 ◽  
Author(s):  
Yong Zhang ◽  
Markus Stoffel ◽  
Eryuan Liang ◽  
Sébastien Guillet ◽  
Xuemei Shao
Keyword(s):  
Tibetan Plateau ◽  
Qilian Mountains ◽  
Complex Landslide ◽  
Landslide Body ◽  
The Qilian Mountains

The mechanics of the Tibetan Plateau

1988 ◽  
Vol 326 (1589) ◽  
pp. 301-320 ◽  
Keyword(s):  
Tibetan Plateau ◽  
Potential Energy ◽  
Thermal Evolution ◽  
Major Change ◽  
Crustal Thickness ◽  
The Tibetan Plateau ◽  
Continental Lithosphere ◽  
Convergence Results ◽  
Late Tertiary ◽  
Deviatoric Stresses

Continental convergence results in compressional deformation over a distance, perpendicular to strike, that is comparable to the length of the convergent boundary. The compressional forces generated by the convergence are resisted, to some extent, by the extensional deviatoric stresses arising from isostatically balanced increases in crustal thickness; as a result a plateau may form, in front of a compressional boundary, whose elevation is limited by the strength of the continental lithosphere. However, the extensional stresses do not exceed the compressional stresses that generate the crustal-thickness contrasts unless there is a major change, either in the convergent velocity or in the potential energy of the elevated region. For the collision of India with Asia, it appears that there has not been a change in the convergent boundary condition sufficient to cause the late-Tertiary to present extension in the region. It is suggested that thermal evolution of the region, involving a delayed convective instability of the base of the thickened lithosphere, could have raised the surface elevation and the potential energy of the Tibetan Plateau, leading to the observed extension there.

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