The capability of time-lapse photography to retrieve snow depth time series was tested. Historically, snow depth has been measured manually by rulers, with a temporal resolution of once per day, and it is a time-consuming activity. In the last few decades, ultrasonic and/or optical sensors have been developed to obtain automatic and regular measurements with higher temporal resolution and accuracy. The Finnish Meteorological Institute Image Processing Toolbox (FMIPROT) has been used to retrieve the snow depth time series from camera images of a snow stake on the ground by implementing an algorithm based on the brightness difference and contour detection. Three case studies have been illustrated to highlight potentialities and pitfalls of time-lapse photography in retrieving the snow depth time series: Sodankylä peatland, a boreal forested site in Finland, and Gressoney-La-Trinité Dejola and Careser Dam, two alpine sites in Italy. This study presents new possibilities and advantages in the retrieval of snow depth in general and snow depth time series specifically, which can be summarized as follows: (1) high temporal resolution - hourly or sub-hourly time series, depending on the camera's scan rate; (2) high accuracy levels - comparable to the most common method (manual measurements); (3) reliability and visual identification of errors or misclassifications; (4) low-cost solution; and (5) remote sensing technique - can be easily extended in remote and dangerous areas.
Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan, 20133, Italy; Finnish Meteorological Institute, Erik Palménin aukio 1, P.O. Box 503, Helsinki, 00101, Finland
Recommended Citation:
Bongio M.,Nadir Arslan A.,Melih Tanis C.,et al. Snow depth time series retrieval by time-lapse photography: Finnish and Italian case studies[J]. Cryosphere,2021-01-01,15(1)