Snow Depth Measurement by Snowboarding with Kinematic GPS

Abstract

Temporal changes of spatially varying snow depth were measured using GPS technique in mountainous area of Miyagi Zao from winter to spring in the season of 2006-07. In the mountainous areas, because the elevation-snow depth distribution data are hardly obtained from snowy season to snowmelt season, these data are valuable. We used the GPS kinematics surveying system, which is in higher reliability for the interferometric positioning of the observation. This method is capable of recording the observations at any point in short and constant time intervals. Two interpolation methods; the nearest neighbor method and 2-point geometric method, were used. By interpolating the GPS observation in both methods, we prepared detail snow depth distribution data corresponding to ground elevation. Observation errors include the error by position change, the calculation error, the morphologic error and the error induced by the snow scale. The total errors induced from above practices are in the range of 0.25 m-0.41 m from nearest neighbor method and 0.25 m-0.40 m from the 2-point geometric method, respectively. The error of 2-point geometric method using GPS ranges 0.34 m-1.10 m in comparing with snow depth measured by snow scale. On the other hand, the error of the nearest neighbor method using GPS observation is 0.12 m-0.30 m. This result, therefore, suggests that the GPS survey with nearest neighbor method is an effective method of observation in mountainous area which gives the precise measurement with the error less than 10 % of total snow depth, when the snow depth is more than 3 m.