Landslides In China Research Articles

A public Cloud-based China’s Landslide Inventory Database (CsLID): development, zone, and spatiotemporal analysis for significant historical events, 1949-2011

Landslide inventory plays an important role in recording landslide events and showing their temporal-spatial distribution. This paper describes the development, visualization, and analysis of a China's Landslide Inventory Database (CsLID) by utilizing Google’s public cloud computing platform. Firstly, CsLID (Landslide Inventory Database) compiles a total of 1221 historical landslide events spanning the years 1949-2011 from relevant data sources. Secondly, the CsLID is further broken down into six zones for characterizing landslide cause-effect, spatiotemporal distribution, fatalities, and socioeconomic impacts based on the geological environment and terrain. The results show that among all the six zones, zone V, located in Qinba and Southwest Mountainous Area is the most active landslide hotspot with the highest landslide hazard in China. Additionally, the Google public cloud computing platform enables the CsLID to be easily accessible, visually interactive, and with the capability of allowing new data input to dynamically augment the database. This work developed a cyber-landslide inventory and used it to analyze the landslide temporal-spatial distribution in China.

Effect of gravel content on creep behavior of clayey soil at residual state: implication for its role in slow-moving landslides

Soil creep is mostly manifested in slow-moving landslides. It is often the case for active slow-moving landslide with slip zone comprising clayey soil where creep would develop in the residual condition. If gravel is presented in clayey soil, this will have considerable impact on creep behavior of clayey soil. However, knowledge about creep behavior of the clayey soil containing gravel particles is scarce. This paper discusses creep behavior of natural clayey soil with gravel at residual state through a series of creep shear tests. Soil samples for this testing program were collected from the slip zones of two large slow-moving landslides in China. The collected soil samples consisted of clayey soil containing various amounts of gravel particles. The test results show that the soil specimens underwent two different creep patterns. An attenuating creep pattern was observed when the soil specimens were subjected to creep stress less than the residual strength, and a creep with increasing strain rate, or a nonattenuating creep pattern, with no evident secondary creep was noted when creep stress was intestinally increased to a level slightly greater than the residual strength. The creep patterns of clayey soil with gravel at the residual state observed in this study were noted to be very consistent with those of the gravel-free clayey soil reported in Bhat et al. (Int J Geomater 1(1):39–43, 2011, Nat Hazards 69(3):2161–2178, 2013) and Di Miao et al. (Eng Geol 162:53–66, 2013). This gives an indication that creep patterns of clayey soils with and without gravel at the residual state are essentially the same, or in other words, that the presence of gravel does not change the creep pattern of clayey soil. However, the test results in this study illustrate that the presence of gravel does have a notable effect on creep behavior of clayey soil. Specifically, the creep stress leading to creep failure of clayey soil and the minimum ratio of the creep stress to residual strength (RCSR) increased with gravel content, and the displacement until the tertiary creep was also larger in samples containing more gravel particles. It is postulated that creep behavior of clayey soil at the residual state in this study and its relationship with gravel content may be related to strength recovery and crushing of gravel-sized particles during creep.

Rainfall data feature extraction and its verification in displacement prediction of Baishuihe landslide in China

Rainfall is one of the main factors that influence the stability of slopes. However, rainfall data have some common features, such as huge data volume and difficulties in direct use. Currently, measurements such as daily rainfall, total rainfall volume and rainfall intensity are widely used for rainfall data feature extraction, which weakens the comprehensive impact of rainfall on slope stability. A feature extraction method for rainfall data is proposed in this paper. Rainfall data is transformed into feature matrices, which have much smaller data volumes. These feature matrices contain lots of useful information and can be used directly in landslide analyses. Based on the statistics of each of the rainfall events, this article applies K-means to classify these events. By dividing rainfall volume into categories of evaporation, infiltration and runoff, feature extraction is conducted. To quantitatively analyze the comprehensive impact of rainfall on landslide stability, Particle Swarm Optimization (PSO) is utilized to search for an array of weight coefficients for evaporation, infiltration and runoff under various rainfall types, which eventually leads to the feature extraction of rainfall data. This feature extraction method is applied to the rainfall data feature analysis of the Baishuihe landslide area. The rationality and validity of the method are verified by the results of landslide displacements predicted by Back-Propagation (BP) neural network. This study provides an effective rainfall data feature extraction method and a new direction for quantitative analysis of landslide monitoring data.

Elementary Analysis of the Mechanism of Xishan Landslide Based on Pixel Tracking on VHR Images

The geometric and kinematic characterizations of landslides are key factors for understanding the mechanisms of landslide movement. Recent developments in remote sensing techniques provide powerful tools for landslide deformation studies. The objective of this paper is to present an efficient method for monitoring the horizontal ground displacement and strain field of active landslides from space-borne optical images, which were analyzed with a digital image correlation technique. This method was evaluated on a series of images acquired on the Xishan landslide in China over the period between 2010 and 2013. These imageries included ZY-3 and WorldView-II images. These were Very High Resolution (VHR) satellite imageries and were orthorectified with a high resolution DEM interpolated from Unmanned Aerial Vehicle (UAV). By using sub-pixel correlation on before- and after-event orthoimages, it was possible to compute the displacement field with high planimetric resolution. Furthermore, a strain analysis was performed to characterize the deformation and displacement regime of the landslide. Validation of the computed strain field analyzed the relationship between the deformation and the faults detected in the field. This approach can facilitate displacement measurements. It could, therefore, offer promising potential for operational applications, for instance, early warning of of geo-hazards.

Risk assessment of disaster chain: Experience from Wenchuan earthquake-induced landslides in China

This paper deals with the formative process of the Wenchuan earthquake disaster chain risk. Selected earthquake-landslides chain risk is critically evaluated by the probability of landslide displacement failure based on the Newmark's permanent-deformation model. In this context, a conceptual model of regional disaster chain risk assessment was proposed, in which the hazardformative environments sensitivity was the core factor as well as the main difference compared with single disaster risk assessment. The disaster chain risk is accumulation of primary disaster risk and the secondary disasters risks. Results derived from the Wenchuan case proved that the conceptual model was suitable for the disaster chain risk assessment, especially the sudden disaster chain. This experience would offer greater potential in application of conceptual model of disaster chain risk assessment, in the process of large-scale disaster risk governance.

The PFC<sup>2D</sup>Simulation of the Slope Stability

The main factors affecting landslide instability are landslides lithologic ,geological structure, topography, climate, hydrological conditions, earthquakes ,human and so on .The risk assessment of landslide is an effective method for analysis landslide stability ,but there has been little research for prediction of landslide in China .In this paper, particle flow procedures is used to analyze the landslide stability under natural conditions and forecast a possible landslide sliding surface ,and a scientific method will be provided for landslide prediction.

Accumulation characteristics, mechanism, and identification of an ancient translational landslide in China

The fluctuation of the water level in a reservoir may induce various types of slope movements. Some of these movements are new, whereas others are old but reactivated. Many ancient landslide accumulations are distributed in the deep valleys of the eastern Qinghai–Tibet Plateau margin in China and will likely be reactivated after the completion of reservoirs and pose a risk to reservoirs, dams, facilities, and towns near mountainous areas. The Shuangjiaping ancient landslide, located in the Dadu River, Sichuan Province, China, is an example of this case. Since August 2010, the western part of the accumulation body has seen the gradual appearance of deformations. The Pubugou reservoir water level rises and inundates the front edge of the accumulation body, thus threatening the safety of the national highway G108 and 37 houses on it. This study is based on field work investigation, drilling work, aerial photography, and profile survey. The site-scale investigation shows that the deformation area is only a part of an ancient landslide accumulation, with an area of approximately 50.4 × 104 m2 and a volume of ca. 956 × 104 m3. Boundary and deposit characteristics of landslide accumulation are specified, which could be divided into four zones, namely, zones A and C, which are an avalanche accumulation area mainly composed of large blocks with diameter ranging from 1 to 3 m (some blocks have a diameter ranging from 5 to 10 m), zone B, a residual integrated rock mass accumulation area with “fake bedrock,” and zone D, a fine material accumulation area. A conceptual model is proposed to explain the mechanism and sliding process of this ancient landslide. The model includes translational sliding, stopping and hanging in air, avalanche accumulating, and transforming. The saltation of topography, material structure, and kinematic characteristics is the evidence used to identify the ancient landslide in deeply incised mountain areas. The current activity is found to be a surficial deposit displacement, and the whole landslide accumulation is stable or quasi-stable.

Slope deformation prior to Zhouqu, China landslide from InSAR time series analysis

A major landslide in Zhouqu, China occurred on August 8, 2010 and caused widespread damage and over 1700 casualties. We study the deformation of the slopes over a time period of about three years prior to the landslide by an enhanced StaMPS-SB technique with 16 ascending ALOS/PALSAR images. In particular, the orbit error and stratified troposphere that were not well dealt with in the original StaMPS-SB method have been satisfactorily corrected by a novel phase ramp correction method. The deformation in four regions of the study area has been retrieved with a maximum of up to 70mm/yr. In the Luojiayu–Sanyanyu valley, the slopes where the 2010 giant landslide occurred have been found to be quite unstable before the event. Deformation exceeding 30mm/yr has been detected in the Suoertou slope, which is a well-known place for an ancient fault zone landslide. Fast movement larger than 40mm/yr is observed in the Xieliupo slope, which poses threats of landslide dam and dammed lake to the Pai-lung River together with another slope deformation detected in the opposite slope. In the Nanshanqiaotou slope, the detected ~30mm/yr deformation can be viewed as the prelude of the large landslide occurred in October 2010. More important, it is found that the slope deformation time series has strong correlation with the precipitation in the area as well as with the devastating Wenchuan earthquake that occurred in May 2008 whose epicenter is about 300km away from Zhouqu.

Displacement evolution of a creeping landslide stabilized with piles

In order to explore the displacement evolution of a creeping landslide stabilized with piles, an analytical model is proposed in this paper. Mechanical behaviors of the sliding surface and the sliding layer in the model are assumed to be visco-plastic and elastic, respectively. Equilibrium of a soil slice in the sliding layer is applied to establish the differential equation, which can be solved as a non-homogeneous heat equation. The displacement of the soil around stabilizing pile is considered as boundary condition at the bottom of the sliding layer, and the stress applied on the upper boundary of the sliding layer is assumed to be a constant. Therefore, the displacement solution of the sliding layer was obtained by solving the non-homogeneous heat equation with the mixed boundary conditions. Subsequently, the analytical model is validated against the monitoring data from Hongyan landslide in China. A good agreement between the measured displacement and the calculated displacement by the proposed model is obtained. Finally, the pile-stabilized region with respect to time, influences of stress distribution in the sliding layer, and the water table on the proposed model are discussed in this paper.

Investigation of Stability of the Critical Rock Blocks that Initiated the Jiweishan Landslide in China

The objective of the paper is to investigate the initiation of the Jiweishan landslide by simulating the field geological conditions around and inside a selected critical rock block and then to study its stability through 3-D discontinuum stress analysis. The study led to the following main conclusions: (1) The mining excavations that occurred underneath the investigated block at the landslide site, the friction angle of T2 discontinuities and sliding plane and the dip angle of the sliding plane seem to be the most important factors with respect to the instability of the investigated block; (2) It seems that the friction angle of T2 discontinuities and sliding plane need to drop to a value between 5° and 10° for the investigated block to be unstable. This means that the rainfall and karstification have played important roles in reducing the said friction angle and contributed to the failure of the investigated block. (3) The northern part of the investigated block (key block) had moved out first from the top of the mountain in a direction parallel to the strike of the north boundary discontinuity plane (T2) and had undergone shear failure on the T2 surface as well as on a weak shale layer (the sliding plane) and the remaining part of the investigated block (driving block) had moved along a direction slightly east of the north direction and had undergone shear failure on the sliding plane and separation from southern and western boundary discontinuity planes (T0 and T1) to fill the empty space created by the key block to initiate the Jiweishan landslide.

New quantitative displacement criteria for slope deformation process: From the onset of the accelerating creep to brittle rupture and final failure

Abstract Two quantitative displacement criteria for slope deformation were deduced through the combination of a one-dimensional renormalization group model and the strain-softening constitutive model of geological materials. The criteria can be used to understand the mechanical process from the onset of the accelerating creep on a slope, through brittle rupture, to the final failure and landslides. The study showed that according to the first criterion, the displacement ratio between the brittle rupture and the onset of the accelerating creep is approximately 1.48, which can be used to predict the brittle rupture of a slope with continuous progressive deformation. The second displacement criterion shows that the displacement ratio between the final failure and the onset of the accelerating creep is approximately 2.59, which can be used to predict the occurrence of the ultimate disaster. Thus, the critical displacement prior to the failure of the slope can be predicted using a time series of monitoring displacement data. The methodology proposed in this study was validated using data from two well-known landslides, the Vajont landslide in Italy and the Xintan landslide in China. The results verify the applicability of this method.

A framework for identifying plant species to be used as 'ecological engineers' for fixing soil on unstable slopes.

Major reforestation programs have been initiated on hillsides prone to erosion and landslides in China, but no framework exists to guide managers in the choice of plant species. We developed such a framework based on the suitability of given plant traits for fixing soil on steep slopes in western Yunnan, China. We examined the utility of 55 native and exotic species with regard to the services they provided. We then chose nine species differing in life form. Plant root system architecture, root mechanical and physiological traits were then measured at two adjacent field sites. One site was highly unstable, with severe soil slippage and erosion. The second site had been replanted 8 years previously and appeared to be physically stable. How root traits differed between sites, season, depth in soil and distance from the plant stem were determined. Root system morphology was analysed by considering architectural traits (root angle, depth, diameter and volume) both up- and downslope. Significant differences between all factors were found, depending on species. We estimated the most useful architectural and mechanical traits for physically fixing soil in place. We then combined these results with those concerning root physiological traits, which were used as a proxy for root metabolic activity. Scores were assigned to each species based on traits. No one species possessed a suite of highly desirable traits, therefore mixtures of species should be used on vulnerable slopes. We also propose a conceptual model describing how to position plants on an unstable site, based on root system traits.

Comparison on landslide nonlinear displacement analysis and prediction with computational intelligence approaches

Landslide displacement is widely obtained to discover landslide behaviors for purpose of event forecasting. This article aims to present a comparative study on landslide nonlinear displacement analysis and prediction using computational intelligence techniques. Three state-of-art techniques, the support vector machine (SVM), the relevance vector machine (RVM), and the Gaussian process (GP), are comparatively presented briefly for modeling landslide displacement series. The three techniques are discussed comparatively for both fitting and predicting the landslide displacement series. Two landslides, the Baishuihe colluvial landslide in China Three Georges and the Super-Sauze mudslide in the French Alps, are illustrated. The results prove that the computational intelligence approaches are feasible and capable of fitting and predicting landslide nonlinear displacement. The Gaussian process, on the whole, performs better than the support vector machine, relevance vector machine, and simple artificial neural network (ANN) with optimized parameter values in predictive analysis of the landslide displacement.

Undrained shear behavior of loess saturated with different concentrations of sodium chloride solution

A series of ring-shear tests was conducted on saturated loess to investigate the effects of NaCl concentration in pore water and desalinization on the shear behavior under undrained conditions. The loess samples were taken from the ground surface of a frequently active landslide in China, were saturated by de-aired, distilled water with different concentrations of NaCl, and then were sheared undrained. After that, the samples were retrieved, remolded, re-set into the shear box, and re-saturated by passing through de-aired, distilled water such that the samples were desalinized, and then were sheared undrained again. Through comparing the undrained shear behavior, the effects of NaCl in the pore-water and desalinization on the undrained shear behavior of loess were examined. The results showed that the variation of NaCl concentration in pore water can strongly affect the shear behavior of saturated loess. Both the peak shear strength and steady-state strength increased with increase of NaCl concentration until a certain value, after which they decreased with further increase of NaCl concentration. Meanwhile, the peak shear strength and steady-state strength of the desalinized samples recovered to those of the original sample; hence, the effects of salinization are reversible. These findings may be of practical importance to better understand the repeated occurrence of some irrigation-induced loess landslides in China.

Debris flow and landslide hazard mapping and risk analysis in China

This paper assesses the hazardousness, vulnerability and risk of debris flow and landslide in China and compiles maps with a scale of 1:6000000, based on Geographical Information System (GIS) technology, hazard regionalization map, socioeconomic data from 2000. Integrated hazardousness of debris flow and landslide is equivalent to the sum of debris flow hazardousness and landslide hazardousness. Vulnerability is assessed by employing a simplified assessment model. Risk is calculated by the following formula: Risk = Hazardousness × Vulnerability. The analysis results of assessment of hazardousness, vulnerability and risk show that there are extremely high risk regions of 104 km2, high risk regions of 283008 km2, moderate risk regions of 3161815 km2, low risk regions of 3299604 km2, and extremely low risk regions of 2681709 km2. Exploitation activities should be prohibited in extremely high risk and high risk regions and restricted in moderate risk regions. The present study on risk analysis of debris flow and landslide not only sheds new light on the future work in this direction but also provides a scientific basis for disaster prevention and mitigation policy making.

Mechanisms of large-scale landslides in China

Large-scale landslides in western China are famous for their size, complex formation mechanism and serious destruction. Data were collected from some typical large-scale landslides in mainland China in the 20th century. A number of geo-mechanical models have been identified: the “three sections” model (sliding; tension cracking; shearing), “retaining wall collapse”, “horizontal-pushing” in horizontal strata; large-scale toppling in counter-inclined strata; the creep-bending–shearing model etc. Large-scale rock landslides are generally accompanied by sudden brittle failure of the “locking section” along the potential sliding surface. The paper discusses the importance of this “locking section” which is key to assessing slope geohazard and to the development of control/mitigation measures.

Formation, distribution and risk control of landslides in China

China is a country with a large population as well as frequent landslides. The formation and distribution of landslides in China are determined by its special topography, complex geological environment, active earthquake environment and unusual climate features. This paper analyzes the main features and distribution of 200 catastrophic landslides that occurred in China since 1900. The relationships among the distribution of landslides and topographic conditions, geological structure, climate features and strong earthquake environment are analyzed. The features of landslide-triggering factors and critical conditions in different areas have also been considered. Based on the above-mentioned work, the authors have undertaken the studies of landslide susceptibility assessment. The study is performed according to the topographic and geological features, which are the main triggering factors that affect the landslides. The Mainland China can be divided into 12 zones, including 4 high susceptibility zones, 7 medium susceptibility zones and 1 low susceptibility zone, according to landslide proneness. Considering the number of life loss and extent of property loss caused by landslides in those 12 zones, the risk evaluation results are listed as follows: 2 extremely high-risk zones, 5 high-risk zones, 2 medium-risk zones and 3 low-risk zones. Taking the number of life loss caused by landslides as the standard of risk level, the paper also analyzes the change in landslide risk level and main risk control measures in China since 1990s. Based on the risk level of landslides in other countries or regions, the acceptable landslide risk level in China has been proposed.

Assessing vulnerability and adaptation responses to rainfall-related landslides in China, a case study of Enshi Prefecture in Hubei Province

Abstract Based on the questionnaire inquiring for landslide disaster of Enshi Autonomous Prefecture in Hubei province, the biophysical, socio-economic, experience, and emergency preparedness and adaptation strategies to disasters characteristics are classified by using SPSS cluster analysis method. It aims to ascertain landslide prone areas in China and assess their vulnerability to flooding and landslide. The results of the cluster analysis of the survey data generated three clusters, high vulnerable-traditional farmers, medium vulnerable-large economical farmers and low vulnerable-commercial and less-farm. The local government should take some accurate and effective measures to protect people and their property from destroying from rainfall-related landslide.

Science for Humanity: Giving Generously to Our World

Hardly a week goes by without some reminder that we live in an age of anxiety and a world in environmental crisis. As I write this message, unusual stratospheric wind patterns in the Northern Hemisphere seem to be implicated in tragic floods in Pakistan, landslides in China, and wildfires near Moscow. The oil spill in the Gulf of Mexico reminds us of our dependence on oil, the increasing scarcity of natural resources, and the adverse environmental impact of our appetite for these resources.The Haiti earthquake earlier this year demonstrates the vulnerability of human society to the natural world. So does the small volcanic eruption in Iceland that disrupted the travel plans of millions of people and cost the aviation industry billions of dollars. Our vulnerability seems to be increasing as the world's population continues to grow, as globalization and interdependencies advance at a giddy pace, and as human societies strive for economic growth.

The dynamic parameter of rainfall: its importance in the prediction of colluvial landslides

The paper discusses rainfall as a dynamic parameter in terms of the load–unload response theory, using the Xintan landslide in China as a case study. The computational results show that an abrupt jump occurs in the curve of the load–unload response ratio just before the landslide takes place. This indicates the potential of the dynamic parameter of rainfall for the prediction of colluvial landslides.