Variation trend of snow depth in the Japanese Alps

2019 Fiscal Year Final Research Report

• Project/Area Number: 15H02958
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Geography
• Research Institution: Shinshu University
• Principal Investigator: SUZUKI Keisuke 信州大学, 理学部, 特任教授 (60145662)
• Co-Investigator(Kenkyū-buntansha): 佐々木 明彦 国士舘大学, 文学部, 准教授 (20608848)
• Project Period (FY): 2015-04-01 – 2020-03-31
• Keywords: 中部山岳地域 / 降積雪深 / 気候変動

Outline of Final Research Achievements

The Japanese Alps experience exceptionally heavy snowfall, and in spring and summer the melting snow becomes a valuable water resource. We were able to obtain climatic and hydrologic data for high-altitude sites in the Japanese Alps, and discuss the variations in these conditions in the Kamikochi region of the Japanese Alps over a 68-year period using these observed data. No long-term trends are observed in the annual mean, maximum, or minimum temperatures at Taisho-ike from 1945 to 2012; the total annual precipitation shows a statistically significant decreasing trend. The annual total snowfall at Taisho-ike from 1969 to 2012 shows a statistically significant increasing trend. The annual total runoff of the Azusa River from 1945 to 2012 shows a statistically significant increasing trend, as does the snowmelt runoff to the river (which occurs from May to July). We can thus conclude that the annual snowfall in the Azusa River catchment has increased in recent years.

Free Research Field

山岳環境学

Academic Significance and Societal Importance of the Research Achievements

気候変動に伴う降積雪量の変動は、水資源や植生分布をはじめとする生態系への影響のみならず、長期的な視点では山岳地域の地形形成作用として影響し、短期的な変動でも豪雪に伴う雪崩災害や多量の融雪水による地滑り災害なども引き起こす。このように、気候変動に伴う降積雪量の変動は重要な課題である。しかし、わが国では、平地に比べて山岳地域には降積雪深の観測地点が少ないこともあり、山岳地域における降積雪深の気候変動に対する応答については、これまであまり研究されていない。また、世界的にも山岳地域における降積雪深の観測が行われていない。本研究によって、中部山岳地域での変動が明らかになった成果は重要である。