Landslide characteristics and, slope instability modeling using GIS, Lantau Island, Hong Kong

A review of techniques, advances and outstanding issues in numerical modelling for rock mechanics and rock engineering

Steep terrain and the high frequency of tropical rainstorms make landslide occurrence on natural terrain a common phenomenon in Hong Kong. For example, more than 800 slope failures were triggered by a rainstorm in November 1993 on Lantau Island, Hong Kong. Maps of recent landslides interpreted from aerial photographs, in combination with a geographical information system, were used to evaluate the frequency and distribution of landslides, with particular reference to such physical parameters as lithology, slope gradient, slope aspect, elevation, vegetation cover, and proximity to drainage line, all of which are considered to be influential in the occurrence of landslides. A stepwise logistic regression model was obtained between landslide susceptibility and the above mentioned physical parameters. The study area has been classified into five classes of relative landslide susceptibility, namely, very low, low, moderate, high, and very high, based on this methodology.

Assessment of landslide susceptibility on the natural terrain of Lantau Island, Hong Kong

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 18. Landslides are a constant in shaping our landscape. Whether by large episodic, or smaller chronic, mass movements, our mountains, hills, valleys, rivers, and streams bear evidence of change from landslides. Combined with anthropogenic factors, especially the development and settlement of unstable terrain, landslides (as natural processes) have become natural disasters. This book charts our understanding of landslide processes, prediction methods, and related land use issues. How and where do landslides initiate? What are the human and economic consequences? What hazard assessment and prediction methods are available, and how well do they work? How does land use, from timber harvesting and road building to urban and industrial development, affect landslide distribution in time and space? And what is the effect of land use and climate change on landslides? [Book Synopsis]

Landslides: Processes, Prediction, and Land Use

Numerical methods in rock mechanics

Analysis of rainstorm-induced slide-debris flows on natural terrain of Lantau Island, Hong Kong

The study area is located in Three Gorges Reservoir region, China. Over 200 landslides have been monitored over a number of years with their behavior being compared to the effective rainfall database for the study area. Analysis of the available data indicates that the occurrences of landslides in this region are controlled by rainfall, whose intensity and rainfall processes are the most important dynamic factors in determining the stability of slopes. Therefore, the relationship between rainfall and the movement of typical landslides has been specifically analyzed for the Xintan landslides and the large Huangya landslide by using the loading/unloading response ratio parameter of rainfall. The result of this study indicates that the mutation of the loading/unloading response ratio of rainfall of the Xintan landslide and the large Huangya landslide in the Three Gorges Reservoir region, China occurred just before their destabilization, which shows that the loading/unloading response ratio of rainfall and its changing feature can be taken as a precursor for the landslides induced by rainfall.

Dynamic features and effects of rainfall on landslides in the Three Gorges Reservoir region, China: using the Xintan landslide and the large Huangya landslide as the examples

Three-dimensional back-analysis of displacements in exploration adits - Principles and application

Data compiled from monitoring the displacement resulting from the Xintan landslide in China was analyzed. The stability of the demonstrated colluvial slope has a close correlation with two parameters, the velocity of the displacement and the angle of the surface vector. The stability trend can be described and evaluated by both the velocity of the displacement and the vector angles. The displacement vector angle, for which there is no substitute, serves as an explicit criterion for the stability of the slope, hence it is significant in the prediction of the catastrophic movement of landslides. A systematic analysis of the features of the vector angles of the surface displacement space and time was performed. The evolving mechanism of space-time and the characteristics of the displacement vector angles were deduced. On the basis of these deductions and by using principles of statistics, the double-parameter threshold for forecasting the stability of the colluvial slopes was established. According to the double-parameter threshold, a calculation and evaluation of stability was completed in terms of the monitoring data of the F-series of points on the Xintan slope. The forecast results coincided with the destabilized timetable, thus demonstrating that the double-parameter criterion has, to a certain extent, precision and practical application for forecasting of landslides.

Double-parameter threshold and its formation mechanism of the colluvial landslide: Xintan landslide, China

After brief introduction of geological processes responsible for rock global circulation,the topic of geological nature of rock is put forward and discussed with emphasizing the intrinsic properties of rock substance,structure and occurrence state,as well as its close relationship with geological evolutionThe difference between rock and other artificial material lies in the geological nature of rock formed in the geological evolutionBased on the recognition of rock nature,the origin of physical inherent properties is discussed including heterogeneity and discontinuity,and their relations with geological nature are also discussedBrief discussion on constitutive property in rock mechanics is madeThe paper attempts to establish a knowledge path from geology to rock mechanics for further collaboration

Wang Sijing

Papers

Analysis of rainstorm-induced slide-debris flows on natural terrain of Lantau Island, Hong Kong

Dynamic features and effects of rainfall on landslides in the Three Gorges Reservoir region, China: using the Xintan landslide and the large Huangya landslide as the examples

Three-dimensional back-analysis of displacements in exploration adits - Principles and application

Double-parameter threshold and its formation mechanism of the colluvial landslide: Xintan landslide, China

Geological nature of rock and its deduction for rock mechanics