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This paper presents the results of applying GIS–MCA–AHP integrated model in landslide susceptibility assessment for warning of dangerous areas in the Tan Uyen district of Vietnam. The main research method is a Multi-criteria assessment that is based on a hierarchical analysis process and a combination of the GIS spatial analysis model. Research results have shown four main groups of factors causing landslides including hydrogeological factors, topographic and geomorphological factors, surface cover factors and human impact factors. The landslide susceptibility assessment map has identified 22.69% of the area (204.96 km2) with a high and very high risk of landslides. Based on the overlapping population distribution map and landslide susceptibility assessment map. It has been shown that residential areas, including 723 households located at a high risk of landslides need to be moved to a safe area. This is a very significant research direction in a warning and minimizing the risk of landslides in mountainous areas of Vietnam. [ABSTRACT FROM AUTHOR]

Complex landslides, capable of reactivation, are typical slope movements in high relief areas. Due to their distribution, size and kinematics, these landforms represent a major hazard, posing a high risk to populations, settlements and infrastructures. This paper integrates geomorphological analyses, instrumental measurements and dendrochronological approaches in assessing a large, reactivated landslide system on the southern piedmont of Monte Sirino (southern Italy). The landslide system is associated with weak geological structures, earthquake activity, and rapid recent incision of the mid-Pleistocene Noce lake deposits. Potential reactivation triggers include a higher regional annual rainfall, one of the highest in southern Italy, and more frequent heavy snowfalls in recent decades. Reactivation of the Sirino landslide system has important implications for the motorway connecting Salerno and Reggio Calabria, which crosses it. The results of our study show that the slide is reactivated with an almost decadal frequency and that major reactivations are correlated to prolonged snowfall, which occurs with increasing frequency in the southern Apennines. The last observation suggests the need for similar studies on the behaviour of other landslide systems in the southern Apennines, performing integrated approaches such as geotechnical and dendrogeomorphological analysis. [ABSTRACT FROM AUTHOR]

This paper discusses the occurrence and development of the excavation-induce deep-seated landslide, which took place near Dündar village, located west of Orhaneli town in northwestern Turkey. The event occurred in the Bursa-Orhaneli lignite field, which has been actively operating since 1979. Due to undermining of a gently inclined slope (10°) to extract a coal seam, primary tension cracks, which were precursors of the movement, were first observed in the northern head area in mid- to late October 2003. This movement happened simultaneously with precipitation that was significantly above long-term average measured at a nearby climatology station (Keles). This precipitation amount is characterized statistically by a significant standardized anomaly of 1.6. The majority of the monthly precipitation total in October 2003, which mainly consisted of rain showers and thunderstorms, occurred in the last week of the month. By April 2004, rotational failure continued intermittently. After a relatively wet (rainy and snowy) period from January 2004 to April 2004, the main rotational slump occurred in late April 2004, causing the entire destruction of Dündar village's cemetery. Daily climatic and synoptic meteorological data have proved that heavy showers in late April may had triggered the last slump by producing rain showers of 19.3 mm and 19.9 mm daily total on 27 and 28 April 2004, respectively. Field observations carried out along the main head scarp have shown that the slope failure was facilitated by a pre-existing normal fault with an east- west direction and 80° dip. Grain-size analysis showed that the failure occurred on clayey silt, which forms 55% of the slip surface material. Based on the evidence from X-ray fluorescence and energy dispersive X-ray spectroscopy results, smectite-type clay - a product of the chemical weathering of tuff - was the main constituent of the slip surface material. The landslide occurred over an area of 600 m × 650 m with a total volume of 8775 000 m3. Approximately 28 hectares of farm land were entirely destroyed and the excavated coal seam was buried. The mining operation was moved to 100 m north of the landslide area near Gümüşpınar village. From morphological evidence, it is concluded that excavation activities caused the failure to extend in more than one direction as an enlarging sliding mechanism; this produced a high landslide risk for Gümüşpınar village, where the most significant normal fault with a 75 m vertical displacement in a coal-bearing sequence is found in the lignite field. [ABSTRACT FROM AUTHOR]