Photogrammetry Applied to Avalanche Studies

• Published in: Journal of Glaciology
• Main Author: van Wijk, M. C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1967
• Subjects: Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000020219; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000020219

Stereophotogrammetric techniques were used for a study of snow avalanches. The contour lines of the avalanche slope were mapped from stereo-photographs taken before and after the occurrence of the avalanche. The outline of the avalanche front at certain time intervals and the contours of the snow cloud were also plotted. A relative accuracy for the different maps of 0.7 m. on the terrain was established. The volume of the snow cloud at four different stages of the avalanche was determined from the maps. These volumes were also computed independently from coordinate readings that were made in the stereo models. The standard errors of both methods of volume determination were estimated to be 450 m. 3 and 290 m. 3 respectively, representing errors of 5 per cent and 3 per cent of the average cloud volume. The photographs were taken with an accurately determined time interval. Therefore, the velocity of the avalanche front could be determined from the photogrammetric measurements.