吹雪時の視程推定手法の改良に関する研究 Improving visibility estimation under snowstorm
This paper proposes an improved method for estimating visibility under snowstorm. The method extends that developed by Matsuzawa and Takeuchi (2002), by incorporating additional weather data. Snowfall intensity, wind velocity, and mass flux of snow were measured under snowstorm, and equations describing the relationship between wind velocity and snow concentration, and that between wind velocity and friction velocity were obtained. The equations were incorporated into the visibility estimation method of Matsuzawa and Takeuchi (2002). Visibility was estimated using weather data obtained by field surveys conducted at the Ishikari Blowing-Snow Test Field. Measured and estimated visibility were each divided into five categories. A correct estimation was defined as agreement between estimated and measured visibility categories. The perfectly percent correct, which is a percentage of the number of correct estimations to the number of all estimations, was calculated for the hourly visibility observation data. The improvements raised the perfectly percent correct to 50% from 36%.
雪氷 69(1), 79-92, 2007-01-15
The Japanese Society of Snow and Ice