Erschienen in:
The Cryosphere, 13 (2019) 12, Seite 3225-3238
Sprache:
Englisch
DOI:
10.5194/tc-13-3225-2019
ISSN:
1994-0424
Entstehung:
Anmerkungen:
Beschreibung:
Abstract. Accurate and timely information on avalanche occurrence is key foravalanche warning, crisis management and avalanche documentation. Today such information is mainly available at isolated locations provided by observersin the field. The achieved reliability, considering accuracy, completenessand reliability of the reported avalanche events, is limited. In this studywe present the spatially continuous mapping of a large avalanche period inJanuary 2018 covering the majority of the Swiss Alps (12 500 km2). We tested different satellite sensors available for rapid mapping during thefirst avalanche period. Based on these experiences, we tasked SPOT6 and SPOT7for data acquisition to cover the second, much larger avalanche period. Wemanually mapped the outlines of 18 737 individual avalanche events, applying image enhancement techniques to analyze regions in the shade as well asin brightly illuminated ones. The resulting dataset of mapped avalancheoutlines, having unique completeness and reliability, is evaluated toproduce maps of avalanche occurrence and avalanche size. We validated themapping of the avalanche outlines using photographs acquired fromhelicopters just after the avalanche period. This study demonstrates the applicability of optical, very high spatial resolution satellite data to map an exceptional avalanche period with veryhigh completeness, accuracy and reliability over a large region. Thegenerated avalanche data are of great value in validating avalanche bulletins,in completing existing avalanche databases and for research applications byenabling meaningful statistics on important avalanche parameters.