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A comparative study of selected bridge damage due to the Wenchuan, Northridge, Loma Prieta and San Fernando earthquakes .s described in this paper. Typical ground motion effects considered include large ground fault displacement, liquefaction, landslide, and strong ground shaking. Issues related to falling spans, inadequate detailing for structural ductility and complex bridge configurations are discussed within the context of the recent seismic design codes of China and the US. A significant lesson learned from the Great Wenchuan earthquake, far beyond the opportunities to improve the seismic design provisions for bridges, is articulated. [ABSTRACT FROM AUTHOR]

This paper deals with landslide hazards and risk analysis of Penang Island, Malaysia using Geographic Information System (GIS) and remote sensing data. Landslide locations in the study area were identified from interpretations of aerial photographs and field surveys. Topographical/ geological data and satellite images were collected and processed using GIS and image processing tools. There are ten landslide inducing parameters which are considered for landslide hazard analysis. These parameters are topographic slope, aspect, curvature and distance from drainage, all derived from the topographic database; geology and distance from lineament, derived from the geologic database; landuse from Landsat satellite images; soil from the soil database; precipitation amount, derived from the rainfall database; and the vegetation index value from SPOT satellite images. Landslide susceptibility was analyzed using landslide-occurrence factors employing the probability-frequency ratio model. The results of the analysis were verified using the landslide location data and compared with the probabilistic model. The accuracy observed was 80.03%. The qualitative landslide hazard analysis was carried out using the frequency ratio model through the map overlay analysis in GIS environment. The accuracy of hazard map was 86.41%. Further, risk analysis was done by studying the landslide hazard map and damageable objects at risk. This information could be used to estimate the risk to population, property and existing infrastructure like transportation network. [ABSTRACT FROM AUTHOR]

— Landslide-induced tsunamis are particularly dangerous because the warning time is very short in the coastal area. Therefore it is critical to identify the potential for coastal landslides involving large masses of material. Almost invariably such large landslides will occur in material susceptible to liquefaction, particularly during earthquakes. This paper discusses characteristics of such materials, how they may be identified, and offers suggestions for estimating the potential for large deformations. [ABSTRACT FROM AUTHOR]

This paper analyses and applies a spatio-statistical failure rate (SSFR) technique for landslide susceptibility zonation in the Hindu Kush region, Pakistan. The study area (Shahpur valley) is located in the eastern Hindu Kush mountain system. In Shahpur valley, land sliding is a recurrent and costly extreme event. Geologically, this region constitutes the youngest mountain systems and almost every year landslide-induced losses are reported. The frequency and intensity of landslide events is expected to further increase in future due to rapid population growth over the fragile slopes, infrastructural development and deforestation. In order to achieve objectives of the study, data were obtained from both primary and secondary sources. In Shahpur valley, an inventory of the past 300 landslide events of various sizes has been identified and marked on a SPOT satellite image of 2.5 m resolution. In order to identify the influence of landslide triggering factors, such as geology, tectonic structures, land use, slope angle, slope aspect, roads and streams, a univariate SSFR technique has been tested and applied for calculating the susceptibility score in each class of the selected parameters. Based on factor maps and cumulative score, the landslide susceptibility zones have been developed and validated appearing to be significantly reflecting the pattern of the past landslide events. [ABSTRACT FROM AUTHOR]

Mass movements are geomorphic processes affecting steeplands all over the world. Mass movement research is comprehensive, but has been concerned mainly with temperate and periglacial areas, while tropical steeplands are still inadequately covered. This paper summarizes research on mass movements carried out since the early 1990s in Nyandarua Range, Kenyaand Uluguru Mountains, Tanzania. Research aspects includeprocesses and causes, aspects of scar recovery, and effects on landscape morphology in a long-term perspective. It is argued that mass movement is the most common denuding agent in the highlands and that natural prerequisites for movement are ample, being of overruling importance in comparison to human- induced movement. Landforms imply that mass movement has been paramount in long-term landscape sculpturing. Recovery of landslide scars is surprisingly fast. In Uluguru Mountains, scars are brought back to agricultural production within about 20 years; in Nyandarua Range considerable physical and chemical recoveryof scar topsoil has taken place within 10 years. Hence, land degradation by mass movement is of transient character. [ABSTRACT FROM AUTHOR]