Herwig Proske

Landslide Susceptibility Maps for Spatial Planning in Lower Austria

Landslides threaten most parts of the provincial state of Lower Austria and cause damage to agricultural land, forests, infrastructure, settlements and people. Thus, the project “MoNOE” (Method development for landslide susceptibility modelling in Lower Austria) was initiated by the provincial government to tackle these problems and to reduce further damage by landslides. The main aim is to prepare landslide susceptibility maps for slides and rock falls and to implement these maps into the spatial planning strategies of the provincial state.

Indicative hazard maps for landslides in Styria; Austria

This study presents Indicative Hazard Maps for gravitational mass movements for the whole of the Province of Styria (Austria) aiming at implementing these maps into the spatial and forestal planning strategies of the provincial administration. Processes taken into account were deep-seated and shallow landslides as well as stone and rock falls. An extensive landslide inventory was generated, based on recently recorded airborne laserscanning data. The landslide susceptibility modelling was based on a statistical approach (logistic regression). This contribution is focused on the methodological approach in generating Indicative Hazard Maps for landslides at regional scale. Due to process-complexity and scale-dependency of input data, landslide susceptibility modelling is still subject to many uncertainties. These will be further addressed in the present contribution.

Different Approaches of Rockfall Susceptibility Maps in Lower Austria

Within the frame of the ongoing project MoNOE (Development of Methods for Modelling Natural Hazards in the Province of Lower Austria) the generation of an indicative multi-hazard map to be used as a scientific reference for regional policies of land use management is one of the main objectives. The applicability and reliability of two relatively simple GIS-based approaches have been analysed aiming at the identification of areas which are potentially endangered by rockfall in a fast and cost-effective manner.

Rockfall runout modelling for hazard zonation considering macro-topographic dispersion

To avoid damage on infrastructure and loss of life, rockfall hazard zonation based on numerical simulation, has become an important tool for land use planning. Due to process-complexity and scale-dependency of input data, rockfall runout modelling is still subject to many uncertainties. Based on the specific geologic conditions (e.g. lithology, fabric, discontinuities, tectonics), detached block sizes at the cliff face vary significantly. Furthermore, released rock masses tend to disintegrate into fragments after the first impact. Depending on size and shape of the detached block and boulder/surface interaction, modelling trajectories of these fragments is a difficult task. A few sophisticated simulation tools are able to consider rebound-effects as well as macro-, and micro-topographic factors controlling lateral dispersion. However, these models require a set of high-precision terrain and vegetation roughness parameters – which are typically not available for large areas. We propose an alternative grid-based approach applicable for runout modelling at regional scale, since today high resolution digital terrain models are available for large areas. Thus, we suggest modelling rockfall propagation by considering macro-topographic lateral dispersion and different boulder sizes even at regional scale. For this purpose we used varying coefficients of friction for different boulder sizes and a rockfall model introducing a stochastic multiple flow algorithm to consider lateral dispersion. The results are evaluated by comparing model results with rockfall deposits derived from field mapping and analysis of orthophotos. Furthermore, the method’s reliability is analyzed in terms of iteration-dependency of the stochastic function. The approach and the model setup have been investigated in a small alpine study area. The results demonstrate that the presented method can contribute to rockfall runout modelling with sufficient accuracy for the generation of indicative hazard maps at regional scale.

Disaster Prevention for Alpine Routes

Natural disasters are an age-old problem that occur regularly in alpine regions, posing a major threat to the safety of settlements and transport routes. Within the project “Safety of Alpine Routes — Application of Earth Observation Combined with GIS (Hannibal)” information has been extracted from satellite remote sensing and integrated into a newly developed GIS based Decision Support System (DSS). Some of the required map information were inferred from ERS- and from SPOT5- and QUICKBIRD satellites. Forest and land cover parameters have been derived from the satellite data. Change detection techniques have been applied to monitor e.g. windfall and clear-cut areas. Methods for interferometric processing of radar data have been optimized to detect landslides and to generate maps of motion fields along the slope surfaces. The results show that this information integrated into the DSS is an efficient tool for focusing the attention to potentially endangered areas.