Airborne laser scanning was used to determine the snow depth distribution in the Kamikochi-Azusa River Basin, located in the upper reaches of the Shinano River, which has multiple snow patches. Snow depth was calculated by comparing ground elevation during the snow-free season and snow surface elevation. Surveys were conducted in the winters of 2012 and 2013. In both winters, the right bank of the Azusa River on the eastern side of the Yari-Hodaka mountain range, which is downwind of the winter monsoon winds, had more snow than the left bank. In the cirque-like terrain on the right bank of the Azusa River, areas with snow depths exceeding 20 m were widely observed. The average snow depth for the entire region was 3.49 m in 2012 and 3.42 m in 2013, representing a 2% difference. However, maximum snow depths for the entire region reached 38.64 m and 42.78 m, respectively, a significant difference. The maximum snow depth in 2013 exceeded that of 2012 in areas where snow patch remained. This is because more avalanche traces were observed in 2013 than in 2012, it is thought that the large amount of snow that formed the snow patches were driven by avalanche accumulation.

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