Search results

The purpose of this paper is to evaluate landslide hazard problems in Hanuman Chatti area of Uttarakhand, India. Every year NH 58 experiences landslide activities, which disrupts the tourist traffic to Badrinath shrine and higher Himalaya.

An urgent need is being felt to have a comprehensive landslide hazard evaluation factor (LHEF). The major causative factors that influence the slope stability are lithology, structure, soil depth, soil texture, geomorphology, slope morphology, slope dip, slope aspect, slope magnitude, weathering, land use and land cover and anthropogenic activities. The present analysis is based on the rating scheme in which numerical ratings for different categories are determined on the basis of their estimated significance in causing instability.

In the study area, nine old landslides (0.238 sq.km) and five new landslides (0.086 sq.km) are recorded. On the basis of the various causative factors the study area is classified into five landslide hazard classes.

The analysis is based on the experience gained for the last seven years (1999‐2007). The period is short for developing any hypothesis but sufficient care has been taken to consider vital factors.

With the help of LHEF appropriate landslide hazard management tools can be adopted. Once a LHEF rating scheme in which numerical ratings for different categories are determined on the basis of their estimated significance in causing instability, is standardized it can be applied to the entire Himalayan region, which is very prone to landslide hazard.

Although the paper is an attempt to evaluate the efficacy of landslide hazard zonation techniques developed by various agencies in the past, some modification as per the requirement has been made in various stages of investigation.

To solve the instability problem of Zhangjiayao landslide caused by rainfall, the internal mechanism of slope instability and the supporting effect of anti-slide piles are studied. The research results can provide theoretical basis for the prevention and control of loess landslides.

A three-dimensional finite element model of Zhangjiayao landslide is established by field geological survey, laboratory test and numerical simulation.

The results show that Zhangjiayao landslide is a loess-mudstone contact surface landslide, and rainfall leads to slope instability and traction landslide. The greater the rainfall intensity, the faster the pore water pressure of the slope increases and the faster the matrix suction decreases. The longer the rainfall duration, the greater the pore water pressure of the slope and the smaller the matrix suction. Anti-slide pile treatment can significantly improve slope stability. The slope safety factor increases with the increase of embedded depth of anti-slide pile and decreases with the increase of pile spacing.

Based on the unsaturated soil seepage theory and finite element strength reduction method, the failure mechanism of Zhangjiayao landslide was revealed, and the anti-slide pile structure was optimized and designed based on the pile-soil interaction principle. The research results can provide theoretical basis for the treatment of loess landslides.

1. A three-dimensional finite element model of Zhangjiayao landslide is established.

2. Zhangjiayao landslide is a loess-mudstone contact surface landslide.

3. The toe of Zhangjiayao slope is first damaged by heavy rainfall, resulting in traction landslide.

4. The deformation of Zhangjiayao slope is highly dependent on rainfall intensity and duration.

5. The anti-slide pile can effectively control the continuous sliding of Zhangjiayao slope.

A three-dimensional finite element model of Zhangjiayao landslide is established.

Zhangjiayao landslide is a loess-mudstone contact surface landslide.

The toe of Zhangjiayao slope is first damaged by heavy rainfall, resulting in traction landslide.

The deformation of Zhangjiayao slope is highly dependent on rainfall intensity and duration.

The anti-slide pile can effectively control the continuous sliding of Zhangjiayao slope.

The overall objective of this study is envisaged to provide decision makers with actionable insights and access to multi-risk maps for the most in-danger stave churches (SCs) among the existing 28 churches at high spatial resolution to better understand, reduce and mitigate single- and multi-risk. In addition, the present contribution aims to provide decision makers with some information to face the exacerbation of the risk caused by the expected climate change.

Material and data collection started with the consultation of the available literature related to: (1) SCs' conservation status, (2) available methodologies suitable in multi-hazard approach and (3) vulnerability leading indicators to consider when dealing with the impact of natural hazards specifically on immovable cultural heritage.

The paper contributes to a better understanding of place-based vulnerability with local mapping dimension also considering future threats posed by climate change. The results highlight the danger at which the SCs of Røldal, in case of floods, and of Ringebu, Torpo and Øye, in case of landslide, may face and stress the urgency of increasing awareness and preparedness on these potential hazards.

The contribution for the first time aims to homogeneously collect and report all together existing spread information on architectural features, conservation status and geographical attributes for the whole group of SCs by accompanying this information with as much as possible complete 2D sections collection from existing drawings and novel 3D drawn sketches created for this contribution. Then the paper contributes to a better understanding of place-based vulnerability with local mapping dimension also considering future threats posed by climate change. Then it highlights the danger of floods and landslides at which the 28 SCs are subjected. Finally it reports how these risks will change under the ongoing impact of climate change.

The purpose of this paper is to attempt to generate a better, systematic and scientific understanding of the basic reasons behind slope instability to help in developing the basic principles of landslide hazard zonation, monitoring and forecasting of landslide hazards for better and more effective landslide hazard mitigation and management.

The study is based on extensive field observations and intensive reviews of literature from secondary sources.

Mass movements especially landslides as they are known to common man are a recurring natural phenomenon and are an integral part of any geological/geomorphological circle of landform development through sequential development of slopes in any elevated region and especially in young fold mountain chains.

The paper presents a valuable insight into the basic reasons behind a landslide to spread awareness, to educate and sensitize people towards better and effective landslide hazard mitigation and thereby ensure people's participation in disaster management. It also aims to initiate and encourage research in the field of landslide management.

Landslides occur frequently and without any appreciable warning as such causing havoc and often insurmountable damage to life and property but despite their uncertainty, their causative factors and indicators of slope instability are very well known to an extent that the magnitude of these events, susceptible areas, the timing of such events and their potential impact can be studied, analyzed and evaluated on the basis of past occurrences and existing knowledge to mitigate their impact. The real value of the present study is to minimize losses due to landslides through better knowledge and enhanced levels of understanding of the phenomenon and its management by simply avoiding those particular reasons that could lead to slope instability problems.

The purpose of this research is to produce the landslide susceptibility map of Fraser's Hill and its surroundings in Pahang (Malaysia), utilizing remote sensing data and Geographic Information System (GIS) as a way to monitor sustainable highland development.

Ancillary data are collected, processed, and constructed into a spatial database in a GIS platform to produce the satellite image. The factors chosen that influence landslide occurrence are land cover, vegetation index (NDVI), precipitation, and geology. Landslide‐hazardous areas are analyzed and mapped using the landslide‐occurrence factors through the heuristic approach Analytic Hierarchy Process (AHP).

It is demonstrated that the integration of remote sensing data and GIS database is of assistance in managing land‐use planning of sustainable development. The verification with the existing landslides record shows a noteworthy accuracy.

The list of data/maps reflects a considerable understanding of the basic cartographic information that is needed to effectively deal with the landslide problem.

This approach indicates a potential long‐term application of remote sensing and GIS in managing sustainable highland development by monitoring the hazard‐susceptibility area.

The value of the work is in its integration and utilization of remote sensing and GIS to provide sustainable development which can be developed to aid landslide warning systems.

The purpose of this paper is to provide an effective way to assess landslide risk quantitatively. Quantitative assessment plays an important role in mitigating the landslide risk and developing a landslide risk-based warning system. However, efficient risk assessment on the large deformation failure process of slope with spatially variable soils is a challenging problem.

Combining the Monte Carlo simulation (MCS) and the higher-order material point method – the B-spline Material Point Method (BSMPM) – the concept of MC-BSMPM to assess the landslide risk quantitatively is proposed in this paper. The overall dynamic evolution of soil slope failure has been simulated by the BSMPM, and the probability density function of the sliding duration, the sliding kinematic energy, the sliding mass and the sliding distance of the landslide are obtained based on the MCS. Through the four risk assessment parameters of the sliding duration, the sliding kinematic energy, the sliding mass and the sliding distance, the landslide risk could be assessed quantitatively.

It is found that the post-failure behavior of the landslide conforms well to a normal distribution as the soil physical parameter is in a normal distribution. The variation of soil’s shear strength affects the dynamic motion of the landslide greatly.

The result shows that the landslide hazard cannot be estimated comprehensively by the deterministic BSMPM, while the landslide risk could be more clearly understood and quantitatively assessed with more details by the proposed method, which demonstrates that the MC-BSMPM method is an effective way to assess the landslide risk quantitatively.

Climatic conditions as also the agrarian economy of the Indian subcontinent is greatly affected by the monsoonal winds that are characterized by heavy rains between June and September. The paper is an attempt to break the myth that landslides are only confined to monsoonal months that normally have concentrated rains and can be expected in other seasons as well and, therefore, disaster alert levels cannot be relaxed during non‐monsoonal season. The communication also attempts to identify slowly ongoing weathering processes that might cause to slope failure without rains and, therefore, paves way for identifying similar landslide prone areas.

The paper discusses two landslides of the recent past; Uttarkashi landslide of 23 September 2003 and Ramolsari landslide of 30 March 2005 that took place after the seizure of the monsoonal rains and is based upon the first hand field observations of the authors. The paper discusses the likely causes of the slides along with the implications of this new trend of landslides taking place in the non‐monsoonal season upon the disaster management strategy of the state.

The investigations reveal that precipitation could be considered the trigger in case of Uttarkashi landslide but there exist no evidences to suggest that the Ramolsari landslide could have been triggered by increased pore water pressure. Slow ongoing and hard to observe processes of weathering seem to have initiated this slide.

For the purpose of metrological parameters, the study relies upon the data of the state run rain gauges that do not have an appreciably good spatial distribution. Rainfall data of the nearest observation points is, therefore, taken as representative of the rainfall in the area under present focus. For Ramolsari, the rainfall data of Tehri is used while Uttarkashi has a rainfall recording observatory.

The paper highlights the importance of keeping the preparedness levels high for prompt post‐disaster operations all through the year. This paper advocates redefining high alert period for landslide hazard and for following high alert all through the year particularly in areas prone to landslides.

The purpose of this paper is to describe how landslide and mass movements are recurring phenomena in the Himalayan region. The consequences in recent times have become more severe in terms of casualties and extensive damage to the roads, buildings, forests, plantation and agriculture fields.

The study is based on field work and secondary source on information about various landslides in the Uttaranchal, India.

In recent years, the intensive construction activity and destabilizing forces of nature have combined to generate huge and complex problems, never encountered before. Implementation of number of hydro‐electric schemes, large‐scale construction of dams, roads, tunnels, buildings, towers, ropeways, tanks and other public utility works as well as indiscriminate mining and quarrying have brought most of instability problems such as never witnessed before.

Mitigation of an active landslide is a difficult option. It has been observed that despite of best technological options available the mitigation of an active landslide costs a lot which is, some times not economically viable.

Prevention is the best practice for landslide management which can be introduced through proper landuse planning.

The proper and scientific management of landslide will certainly reduce the miseries of the community living in this region. However, for that we must be addressed certain issues.

This paper aims to promote sustainable development through disaster management.

The study is based on extensive field observations and intensive review of literature from secondary sources.

In recent times landslides have increased both in frequency and intensity and have assumed catastrophic and disastrous proportions, causing extensive damage to life and property and posing great problems and serious challenges to man and his development process. This increase has been triggered by a combination of several attributes (geological, morphometric, climatic and anthropogenetic) that directly or indirectly cause slope instability, most of which (if not all) are either man‐made or man‐accelerated. Thus, most of the disasters are natural events aggravated by undue human intervention. Man, through his intervention, has accelerated this natural process and his encroachment on the relatively unsafe areas has turned them into disasters. The effect of man on natural processes can be judged from the fact that the frequency of natural disasters/hazards has recorded more than a fivefold increase just in the last two decades, despite all the hue and cry that has been going on all round the world. The economic losses on account of such happenings have shot up by over 3.5 times, and the rise in total insured losses is about six times and, with the present trends (particularly of ignorance, carelessness, lack of will and finances, greed, increasing population and also human demands) and situations, it can safely be predicted that the worst is still to come.

Landslides are a natural phenomenon and every year hundreds of major and minor landslides occur in the hills, though only a few major ones are reported by the print and electronic media, and still fewer are studied and/or analyzed in some detail. The present paper presents a valuable insight into various aspects of landslide management to spread awareness, to educate and sensitize people towards better and effective landslide hazard mitigation and thereby ensure people's participation in disaster management. It also aims to initiate and encourage research in the field of landslide management.

The paper hopes to minimize losses due to landslides through better knowledge and enhanced levels of understanding of the phenomenon and its management.

Malaysia is an ex‐colonial, newly‐industrialising country, with a sustained high economic growth rate averaging eight per cent GDP per annum over the past ten years. Within such a rapidly booming economy, the pace of social, economic and political change is fast, as is the pace of technological change. Other things being equal, these are the changes in which environmental hazards can be magnified. As a result of rapid economic development, physical systems are disturbed and changed. For example, the modification of the hydrological cycle due to deforestation, urbanisation, development of hill slopes and other human land use have given rise to increased risks of landslides. In recent years, the collapse of a block of luxury condominiums in Kuala Lumpur, the Genting Highland and Pos Dipang landslide tragedies as well as other landslide disasters have caused substantial loss of life and damage to property and infrastructure. Combined with intensive development of hill slopes and hill land for housing, recreation, tourism, agriculture, highway and dam construction, and other human induced land use changes, the exposure and vulnerability of human populations to landslide hazards have also increased. Other reasons, largely structural, such as persistent poverty, low residential and occupational mobility, and landlessness, manifested in illegal squatting and farming on hill slopes and foothills have also contributed to increased vulnerability of large communities to landslide hazards in many parts of the country. As Malaysia pushes ahead to meet its target of becoming a fully industrialised country by the year 2020, further environmental degradation is expected to occur. Notwithstanding other aspects of environmental degradation, the occurrence of landslide hazards is expected to become a common feature of Malaysian life.