LONG-TERM CHANGES IN SNOWFALL AND SNOW DEPTH IN TOYAMA PREFECTURE DURING 1974-2015

Abstract

 The purpose of this study is to clarify the temporal and spatial distribution of snowfall and snow-depth in Toyama prefecture for 43 years from 1973 to 2015. Daily mean air temperature, daily snowfall and daily snow-depth of 64 weather stations from 1 December to 31 March as snowfall season were used, and Mann-Kendall trend test was selected as one of non-parametric tests for this study.

 As a result of trend test, minimum air temperature of 45 weather stations had positive trend, 14 weather stations increased significantly (p value <0.05). Snowfall of 50 weather stations had negative trend, 25 weather stations decreased significantly (p value <0.05). Snow-depth of 47 weather stations had negative trend, 18 weather stations decreased significantly (p value <0.05). The decreasing trend of snowfall and snow-depth was remarkable in plain area. On the other hand, there was no significant trend of increase or decrease in mountainous area.