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Liechtenstein has faced an increasing number of natural hazards over recent decades: debris flows, slides, snow avalanches and floods repeatedly endanger the local infrastructure. Geomorphological field mapping and geoelectrical profiling was used to assess hazards near Malbun, a village potentially endangered by landslides, and especially debris flows. The area is located on the tectonic contacts of four different nappe slices. The bedrock consists of anhydrite and gypsum, dolomite, shale, marl, and limestone. The spatial distribution and occurrence of debris flows and slides is evaluated through a combination of geomorphological expert knowledge, and detailed visualization in a geographical information system. In a geo-database a symbol-based 1:3000 scale geomorphological map has been digitized and rectified into polygons. The polygons include information on the main geomorphological environment, the Quaternary material distribution and of geomorphological processes, which are stored in attribute tables. The spatial distribution of these attributes is then combined with geophysical information and displacement rates interpolated from benchmark measurements. On one of the landslides two geo-electrical profiles show that the distance to a potential failure plane varies between 10-20m and that the topography of the failure plane is influenced by subterranean gypsum karst features. The displacement measurements show that this landslide actively disintegrates into minor slides and is not, therefore, a risk to the village of Malbun. The hazard zonation indicates that debris flows can pose a risk if no countermeasures are taken. Gypsum karst may locally accelerate the landslide activity. In contrast, the impact of debris flows is diminished because collapse dolines may act as sediment traps for the debris flow materials. This research illustrates how geomorphological expert knowledge can be integrated in a GIS for the evaluation of natural hazards on a detailed scale. [ABSTRACT FROM AUTHOR]

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Abstract: The Corvara landslide is an active slow moving rotational earth slide - earth flow, located uphill of the village of Corvara in Badia, one of the main tourist centres in the Alta Badia valley in the Dolomites (Province of Bolzano, Italy). Present-day movements of the Corvara landslide cause National Road 244 and other infrastructures to be damaged on a yearly basis. The movements also give rise to more serious risk scenarios for some buildings located in front the toe of the landslide. For these reasons, the landslide has been under observation since 1997 with various field devices that enable slope movements to be monitored for hazard assessment purposes. Differential GPS measurements on a network of 47 benchmarks has shown that horizontal movements at the surface of the landslide have ranged from a few centimetres to more than 1 m between September 2001 and September 2002. Over the same period, vertical movements ranged from a few centimetres to about 10 cm, with the maximum displacement rate being recorded in the track zone and in the uppermost part of the accumulation lobe of the landslide. Borehole systems, such as inclinometers and TDR cables, have recorded similar rates of movement, with the depths of the major active shear surfaces ranging from 48 m to about 10 m. From these data, it is estimated that the active component of the landslide has a volume of about 50 million m3. In this paper the monitoring data collected so far are presented and discussed in detail to prove that the hazard for the Corvara landslide, considered as the product of yearly probability of occurrence and magnitude of the phenomenon, can be regarded has as medium or high if the velocity or alternatively the volume involved is considered. Finally, it is also concluded that the monitoring results obtained provide a sound basis on which to develop and validate numerical models, manage hazard and support the identification of viable passive and active mitigation measures. [Copyright &y& Elsevier]