Towards a national susceptibility map for rock avalanches for Norway
Abstract
Latest development in high resolution remote sensing data, that are freely available for the first time, allows to study rock slope deformation that might lead to catastrophic failure events on a national scale. This study aims to create a susceptibility map for rock avalanches in Norway based on the following steps:
Systematic screening of remote sensing data to locate potential unstable rock slopes Semi-automated volume estimation Automized run-out assessment Empirical displacement wave run-up height assessment The project has just started, and we are setting up the first step. High resolution digital elevation data acquired by airborne laser scanning (ALS) will cover the entire land surface of Norway by 2022 (https://hoydedata.no/LaserInnsyn/). ALS data is the only data set allowing to map the morphology of the ground surface. ALS data, however, will only reveal deformation features but does not allow to assess their state of activity, which can be dormant or stabilized today. In addition, multiple generations of aerial photos are freely available (https://www.norgeibilder.no/). These can indicate the activity of rock slopes due to vegetation damage. Furthermore, Norway is the first country that has developed a full cover of InSAR based ground surface deformation data (https://insar.ngu.no/). Those data are of large value as they indicate areas that deform actively today. Thus, a combination of the three data sources guarantees that all unstable slopes can be detected and ranked qualitatively based on activity. In order, to minimize the area that needs to be analysed, the study area is restricted to areas with sufficient relief, presence of housing and the distance to shorelines in order to account for the consequences of displacement waves. This allows to reduce the study area significantly from the total land area of Norway from 323,778 km2 down to roughly the half. The resulting susceptibility map will serve as a source to prioritize mapping and mitigation effort, also with respect to other natural hazards in Norway. Furthermore, it will be a base for efficient areal planning on a local level. Compared to susceptibility maps for other natural hazards, the susceptibility map for rock avalanches in Norway depicts all rock slopes with signs of post-glacial deformation as "real" source areas.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMNH0270001B
- Keywords:
-
- 1810 Debris flow and landslides;
- HYDROLOGY;
- 1826 Geomorphology: hillslope;
- HYDROLOGY;
- 4302 Geological;
- NATURAL HAZARDS;
- 4313 Extreme events;
- NATURAL HAZARDS