Spatial and temporal variations of Norwegian geohazards in a changing climate, the GeoExtreme Project

Abstract. Snow avalanches in mountainous areas pose a significant threat to infrastructure (roads, railways, energy transmission corridors), personal property (homes) and recreational areas as well as for lives of people living and moving in alpine terrain. The impacts of snow avalanches range from delays and financial loss through road and railway closures, destruction of property and infrastructure, to loss of life. Avalanche warnings today are mainly based on meteorological information, snow pack information, field observations, historically recorded avalanche events as well as experience and expert knowledge. The ability to automatically identify snow avalanches using Very High Resolution (VHR) optical remote sensing imagery has the potential to assist in the development of accurate, spatially widespread, detailed maps of zones prone to avalanches as well as to build up data bases of past avalanche events in poorly accessible regions. This would provide decision makers with improved knowledge of the frequency and size distributions of avalanches in such areas. We used an object-oriented image interpretation approach, which employs segmentation and classification methodologies, to detect recent snow avalanche deposits within VHR panchromatic optical remote sensing imagery. This produces avalanche deposit maps, which can be integrated with other spatial mapping and terrain data. The object-oriented approach has been tested and validated against manually generated maps in which avalanches are visually recognized and digitized. The accuracy (both users and producers) are over 0.9 with errors of commission less than 0.05. Future research is directed to widespread testing of the algorithm on data generated by various sensors and improvement of the algorithm in high noise regions as well as the mapping of avalanche paths alongside their deposits.

Section: Avalanche Hazardssupporting

confidence: 51%

Automated detection of snow avalanche deposits: segmentation and classification of optical remote sensing imagery

Lato

Frauenfelder

Bühler³

2012

“…As a result, researchers are becoming more and more interested in understanding possible correlations between slope instabilities and climate change (Collison et al, 2000;Jaedicke et al, 2008;Jakob and Lambert, 2009). Particular attention has been focused on the role played by permafrost degradation, and the consequent thawing of the ice filling the rock joints (Fischer et al, 2006;Gruber and Haeberli, 2007;Chiarle and Mortara, 2008;Huggel, 2009).…”

Section: Recent Climatic Changesmentioning

confidence: 99%

Microseismic activity analysis for the study of the rupture mechanisms in unstable rock masses

Amitrano

Arattano

Chiarle

et al. 2010

Abstract. Rockfalls are common instabilities in alpine areas and can cause significant damage. Since high mountains have been affected by an increasing number of these phenomena in the last years, a possible correlation with permafrost degradation induced by climate change has been hypothesized.To investigate this topic, a monitoring system, made of 5 triaxial geophones and 1 thermometer, was installed in 2007 at the Carrel hut (3829 m a.s.l., Matterhorn, Northwestern Alps), in the frame of the Interreg IIIA Alcotra project n. 196 "Permadataroc".The preliminary data processing relates to the classification of recorded signals, the identification of the significant microseismic events and the analysis of their distribution in time and space. The first results indicated a possible correlation between clusters of events and temperature trend, and a concentration of events in specific sectors of the rock mass.Research is still in progress. The recording of data for a longer period is planned to fully understand seasonal trends and spatial distribution of microseismic activity, and possible relations with permafrost degradation. Nevertheless, the preliminary observations prove that the monitoring system can detect noises generated by rock slope deformation. Once fully developed, this technique could become a helpful tool for early warning and preliminary stability assessments.

“…However, a strong demand exists for effective methods of regional-scale analysis to estimate wind erosion hazards and sensitivities, since regional scale is suitable for environmental, landscape or spatial planning applications of agricultural and environmental programs (Jaedicke et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Estimation of regional differences in wind erosion sensitivity in Hungary

Mezősi

Blanka

Bata

et al. 2015

Abstract. In Hungary, wind erosion is one of the most serious natural hazards. Spatial and temporal variation in the factors that determine the location and intensity of wind erosion damage are not well known, nor are the regional and local sensitivities to erosion. Because of methodological challenges, no multi-factor, regional wind erosion sensitivity map is available for Hungary. The aim of this study was to develop a method to estimate the regional differences in wind erosion sensitivity and exposure in Hungary.Wind erosion sensitivity was modelled using the key factors of soil sensitivity, vegetation cover and wind erodibility as proxies. These factors were first estimated separately by factor sensitivity maps and later combined by fuzzy logic into a regional-scale wind erosion sensitivity map. Large areas were evaluated by using publicly available data sets of remotely sensed vegetation information, soil maps and meteorological data on wind speed. The resulting estimates were verified by field studies and examining the economic losses from wind erosion as compensated by the state insurance company. The spatial resolution of the resulting sensitivity map is suitable for regional applications, as identifying sensitive areas is the foundation for diverse land development control measures and implementing management activities.