北海道地区自然災害科学資料センター報告
Vol.35, 3-11, 20222020㸫2021 ᖺ෤ᮇࡢᒾぢἑ኱㞷ㄪᰝሗ࿌㸫✚㞷࡜㝆㞷ࡢ≉ᚩ㸫

Report on Heavy Snowfall in Iwamizawa in Winter 2020㸫2021– Characteristics of Snow Cover and Weather Conditions –ᑿ㛵 ಇᾈ 1㸪ⓑᕝ 㱟⏕ 2㸪㔠⏣ Ᏻᘯ 3㸪ᯇᒸ ┤ᇶ 41㸪໭ᾏ㐨ᩍ⫱኱Ꮫᮐᖠᰯ
2㸪໭ぢᕤᴗ኱Ꮫ
3㸪୍⯡♫ᅋἲே໭ᾏ㐨㛤Ⓨᢏ⾡ࢭࣥࢱ࣮
4㸪ᰴᘧ఍♫໭ᾏ㐨Ẽ㇟ᢏ⾡ࢭࣥࢱ࣮
Toshihiro Ozeki1, Tatsuo Shirakawa2, Yasuhiro Kaneda3, Naoki Matsuoka4
1㸪Hokkaido University of Education Sapporo
2㸪Kitami Institute of Technology
3㸪Hokkaido Development Engineering Center4㸪Hokkaido Weather Technology Center

AbstractIn the winter of 2020-2021, heavy snowfall hit around Iwamizawa area, with the maximum
snow depth of 205 cm. It was the second deepest after 208 cm in the winter of 2011-2012. Foursnow surveys were conducted in Iwamizawa in February and March 2021, and compared tothe 2021-2012 snow survey. In the winter of 2020-2021, although temperatures in this winterwere normal, they fluctuated largely. Then, most of the grain shape had metamorphosed into
melt forms by late February. On the other hand, the values for snow depth and snow waterequivalent were almost the same. The westerly wind was predominant in Iwamizawa thiswinter. As a result, there were many events where snow clouds flowed from Ishikari Bay toIwamizawa area.
Key Words: heavy snow, snowfall, snow survey, snowpack observation, grain shape࣮࣮࢟࣡ࢻ㸸኱㞷㸪㝆㞷㸪✚㞷ㄪᰝ㸪✚㞷᩿㠃ほ 㸪㞷㉁1㸬ᴫせ2020㸫2021 ᖺ෤ᮇ㸪ᒾぢἑᕷ࿘㎶ࡣ኱㞷࡟ぢ⯙ࢃࢀࡓࠋᒾぢἑࡢ᭱῝✚㞷ࡣ 205cm㸦2 ᭶25 ᪥㸸ィჾᨾ㞀࡟ࡼࡿḞ ࢆྵࡴ್㸧ࢆグ㘓ࡋ㸪ࡇࢀࡣ 2011㸫2012 ෤ᮇࡢ᭱῝✚㞷 208cm1)࡟ḟࡄㄪᰝグ㘓࡛࠶ࡗࡓࠋࡇࡢᙳ㡪࡟ࡼࡾ㸪✵㛫ࡢ㛢ሰࡸᅽᐦỿ㝆࡟ࡼࡿ㞷ᐖࡀ」ᩘⓎ⏕ࡋ㸪㐨㊰஺㏻⥙ࡢ㯞⑷ࡸ㕲㐨ࡢ㐠ఇ㸪㞷࡟ࡼࡿᘓ≀ࡢಽቯ࡞࡝㸪ᆅᇦ⤒῭ࡸᕷẸ⏕ά࡟኱ࡁ࡞ᨭ㞀ࡀ⏕ࡌࡓ 2), 3)ࠋ

3ᮏㄪᰝ࡛ࡣᒾぢἑ࡟࠾࠸࡚ 2021 ᖺ 2 ᭶࡟ 3 ᗘ㸪3 ᭶࡟ 1 ᗘࡢ✚㞷ㄪᰝࢆ⾜࠸㸪2011㸫2012ᖺ࡟㞷ịᏛ఍໭ᾏ㐨ᨭ㒊㞷ị⅏ᐖㄪᰝࢳ࣮࣒ࡀᒾぢἑ࡛⾜ࡗࡓ✚㞷ㄪᰝ⤖ᯝ 1), 4), 5)࡜ẚ㍑ࡋࡓࠋ
ࡉࡽ࡟㸪໭ᾏ㐨ࡢ௒෤ࡢ㝆㞷ࢆᴫほࡋ㸪ᒾぢἑࡢ௒෤ࡢ㝆✚㞷ࡢ≉ᚩ࡜ࡑࢀࢆࡶࡓࡽࡋࡓ㞼ࡢ㐍ධࣃࢱ࣮ࣥࢆㄪᰝࡋࡓࠋ2㸬ㄪᰝ᪉ἲᒾぢἑᕷෆࡢ✚㞷ㄪᰝࡣ 2 ࡘࡢࢳ࣮࣒࡟ศ࠿ࢀ࡚ሙᡤ࡜᪥ࢆኚ࠼࡚⾜ࡗࡓࠋⴭ⪅ࡢ࠺ࡕᑿ㛵ࡣ໭ᾏ㐨ᩍ⫱኱Ꮫᒾぢἑᰯ㸦௨ୗᒾᩍ኱㸧ࢢࣛ࢘ࣥࢻ㸦43° 11’ 15.5” N㸪141° 46’ 45.9” E㸧࡟࠾࠸࡚ 2021 ᖺ 2 ᭶ 16 ᪥࡜ 2 ᭶ 28 ᪥ࡢ 2 ᅇ✚㞷᩿㠃ㄪᰝࢆ⾜ࡗࡓ 6)ࠋ୍᪉㸪ⓑᕝࡣᒾぢἑᕷႠ࠶ࡉࡂࡾබᅬ㸦43° 12’ 42.0” N㸪141° 44’ 58.0” E㸧࡟࠾࠸࡚ྠᖺ 2 ᭶ 21 ᪥࡜ 3 ᭶ 5 ᪥ࡢ 2ᅇ✚㞷᩿㠃ほ ࢆ⾜ࡗࡓ 7)ࠋࡇࡢ 2 ᆅⅬࡣᒾぢἑᕷ⾤ࡢ༡࡜໭࡟఩⨨ࡍࡿࠋࡲࡓ㸪ࡇࡢ᫬ᮇࡣ໭ᾏ㐨ࡢᖹᆅ࡟࠾࠸࡚ࡣ⼥㞷ὶฟࡀ㉳ࡁࡿ๓࡛࠶ࡾ㸪✚㞷Ỉ㔞ࡀ᭱኱࡟㏆࠸࡜ぢ࡞ࡏࡿࡇ࡜࠿ࡽ㸪㐣ཤࡢᗈᇦ✚㞷ㄪᰝࡢከࡃࡶࡇࡢ᫬ᮇ࡟ᐇ᪋ࡉࢀ࡚࠸ࡿࠋほ᪉ἲ࡜⾲グࡣ✚㞷ほ࢞࢖ࢻࣈࢵࢡ 8)࠾ࡼࡧᏘ⠇✚㞷ࡢᅜ㝿ศ㢮 9)࡟‽ࡌ࡚ᐇ᪋ࡋࡓࠋㄪᰝ㡯┠ࡣ✚㞷῝㸪ᒙᵓ㐀࠾ࡼࡧ✚㞷Ỉ㔞ࡢ 3 㡯┠࡛࠶ࡿࠋᆅୖẼ㇟ほ ࢹ࣮ࢱࡣ໭ᾏ㐨ෆࡢ 14 ᣺⯆ᒁࡢẼ㇟ᗇࢹ࣮ࢱࢆ౑⏝ࡋࡓࠋࡲࡓ㸪Ẽ㇟ᗇࡢゎᯒ✚㞷῝㸪ᮐᖠ㧗ᒙほప

850 hPa ࡜࣮ࣞࢲ࣮࢔࣓ࢲࢫྜᡂᅗࢆ౑⏝ࡋࡓࠋ✚㞷Ỉ㔞ࡣ໭ᾏ㐨኱Ꮫ⛉Ꮫ◊✲ᡤࡀᐇ᪋ࡋࡓᗈᇦ✚㞷ㄪᰝࡢグ㘓ࢆ౑⏝ࡋࡓࠋ

ᅗ 1
 ௒෤ࡢᒾぢἑࡢ✚㞷῝࡜✚⟬㝆㞷㔞 10) 㸦ᒾぢἑ AMeDAS㸧㸧3㸬ㄪᰝ⤖ᯝ࡜⪃ᐹ
3-1 2020㸫2021 ᖺ෤ᮇࡢ໭ᾏ㐨ࡢ㝆㞷ࡢ≉ᚩẼ㇟ᗇᒾぢἑ≉ูᆅᇦẼ㇟ほᡤ࡟࠾ࡅࡿ✚⟬㝆㞷㔞࡜᭱῝✚㞷ࡢ᥎⛣ࢆᅗ 1 ࡟♧ࡍ 10)ࠋ2020 ᖺ 12 ᭶ 1 ᪥࡟᪥㝆㞷㔞 51cm
㸦12 ᭶ࡢほ ྐୖ 6 ఩㸧㸪2021 ᖺ 2 ᭶ 25 ᪥࡟᭱῝✚㞷 205cm
㸦ほ ྐୖ 2 ఩㸧ࢆグ㘓ࡍࡿ࡞࡝㸪㝆㞷࣭✚㞷࡜ࡶ࡟ᖹᖺࢆୖᅇࡿ኱㞷࡜࡞ࡗࡓࠋᅗ 1 ࡟ࡣ㸪ᖹᖺ㸦1981㹼2010 ᖺࡢ 30 ᖺᖹᆒ㸧ࡢ✚⟬㝆㞷㔞࡜᭱῝✚㞷ࡶྜࢃࡏ࡚♧ࡋࡓࠋ᭶✚㞷῝࡛ࡣ
12 ᭶࡟ほ ྐୖ 1 ఩㸪1 ᭶࡟ྠ 2 ఩㸪2 ᭶࡟ྠ 2 ఩ࢆࡑࢀࡒࢀグ㘓ࡋࡓࠋࡲࡓ㸪ᒾぢἑࡢ 124᭶ࡢ㝆㞷῝ࡣ 382cm ࡜ᖹᖺࡼࡾ࠿࡞ࡾከࡃ㸦ᖹᖺẚ 191%㸪ㄪᰝྐୖ➨ 3 ఩㸧㸪2᭶ࡶ 227cm㸦ᖹᖺẚ 142%㸧࡜ᖹᖺࢆከࡃୖᅇࡗࡓࠋࡇࢀࡣ඲㐨ⓗ࡟ࡣ෤ᮇࢆ㏻ࡋ࡚㝆㞷῝ࡣ඲⯡࡟ᖹᖺ୪ࡳ࠿ࡽᖹᖺࡼ
ࡾࡸࡸᑡ࡞┠࡛࠶ࡗࡓࡇ࡜࡜ᑐ↷ⓗ࡛࠶ࡿࠋᅗ 2 ࡟㸪ᒾぢἑࡢ఩⨨ࡍࡿ▼⊁ᖹ㔝࡟ἢࡗ࡚㸪༡すࡢᮐᖠ࠿ࡽ໭໭ᮾࡢᖠຍ
ෆ࡟࠿ࡅ࡚ࡢ᪥ᮏᾏഃࡢ࢔࣓ࢲࢫᆅⅬࡢᅗ 2 2020--2021 ෤ᮇ࡟࠾ࡅࡿᮐᖠ࠿ࡽᖠຍຍෆ࡟࠿ࡅ࡚㝆㞷ࡢ῝ࡉࡢᖹᖺᕪࢆ♧ࡋࡓࠋᒾぢἑ࠿ࡢ⣼ィ㝆㞷῝ࡢᖹᖺẚ㍑ 6)

ࡽ༡す࡬⣙ 40km ࡢᮐᖠ㸪ᒾぢἑ࠿ࡽ໭す࡬⣙ 12km 㞳ࢀࡓ᪂⠛ὠ࢔࣓ࢲࢫࢆྵࡵ㸪ᮏࣛ࢖ࣥୖ࡛㝆㞷ࡢ῝ࡉࡀᖹᖺ್ࢆୖᅇࡗࡓࡢࡣᒾぢἑࡔࡅ࡛࠶ࡗࡓࠋࡉࡽ࡟໭ᾏ㐨 14 ᣺⯆ᒁࡢ௦⾲ᆅⅬ࡟ࡘ࠸࡚෤ᮇ⣼ィ㝆㞷㔞ࢆㄪ࡭ࡓ࡜ࡇ
ࢁᮐᖠࡀᖹᖺࢆ 266cm ୗᅇࡿ࡞࡝᪥ᮏᾏഃࢆ୰ᚰ࡟඲⯡࡟ᖹᖺࡼࡾᑡ࡞ࡃ㸪඲㐨ⓗ࡟ᖹᖺࢆୗᅇࡿ㝆㞷㔞࡛࠶ࡗࡓࠋ୍᪉㸪ᒾぢἑ࡛ࡣ 12 ᭶࠿ࡽ 2 ᭶࡟࠿ࡅ࡚㝆㞷ࡀከࡃ࡞ࡾ㸪෤ᮇ඲య࡛ࡣ
ᖹᖺࡼࡾ 193cm ከࡃ㸪ᖹᖺࢆ኱ࡁࡃୖᅇࡗ࡚࠸ࡓ 11)ࠋᅗ 3 ࡟ 2021 ᖺ 2 ᭶ 24 ᪥ 14 ᫬ࡢ▼⊁ᖹ㔝࿘㎶ࡢẼ㇟ᗇゎᯒ✚㞷῝ࢆ♧ࡋࡓ㸦ᅗ 3 ᕥ㸧ࠋࡲࡓ㸪ẚ㍑ࡢࡓࡵ࡟㞷ị⅏ᐖㄪᰝࢳ࣮࣒ࡢほࢹ࣮ࢱ࠿ࡽసᡂࡋࡓ 2012 ᖺ 2 ᭶ᮎࡢ▼⊁ᖹ㔝࿘㎶㸦ᶆ㧗 100 m ௨ୗࡢᖹᆅ✚㞷㸧ࡢ✚㞷῝ศᕸ 4)ࡢࢆ♧ࡋࡓ㸦ᅗ 3 ྑ㸧ࠋᅗ 3 ྑᅗ㉥୸࡟♧ࡍࡼ࠺࡟㸪2012 ᖺࡣᙜู㸪᭶ᙧ㸪᪂⠛ὠ࠿ࡽᒾぢἑ࡟࠿ࡅ࡚✚㞷῝ࡀ኱ࡁ࠿ࡗࡓࡢ࡟ᑐࡋ㸪2021 ᖺࡣ✚㞷ࡢከ࠸㡿ᇦࡣᒾぢἑ࡟ᐤࡗ࡚࠸ࡓ
㸦ᅗ 3 ᕥᅗ㉥୸㸧ࠋࡲࡓ㸪2021 ᖺࡣ⁪ᕝ࠿ࡽ῝ᕝ࡟࠿ࡅ࡚ࡢᆅᇦࡢ✚㞷῝ࡀᑠࡉ࠸ࡇ࡜ࡶ≉ᚩ࡛࠶ࡗࡓ㸬௨ୖࡼࡾ㸪ᒾぢἑ௜㏆࡟኱㞷ࡀ㞟୰ࡋࡓࡇ࡜ࡀ௒෤ᮇࡢ኱ࡁ࡞≉ᚩ࡛࠶ࡗࡓࠋ

ᅗ 3 2021 ᖺ 2 ᭶ 24 ᪥ 14 ᫬ࡢ▼⊁ᖹ㔝࿘㎶ࡢẼ㇟ᗇゎᯒ✚㞷῝㸦ᕥ㸧࡜ 2012 ᖺ 2 ᭶ᮎࡢ▼⊁ᖹ㔝࿘㎶ࡢ✚㞷῝ 4)㸦ྑ㸧ࡢ
ࡢẚ㍑㸦
㸦2012 ᖺࡣᙜู࠿ࡽᒾぢἑ࡟࠿ࡅ࡚✚㞷῝ࡀ኱኱ࡁ࠿ࡗࡓ㸦ྑᅗ‫ۑ‬‫ۑ‬㸧
㸬22021 ᖺࡣ✚㞷ࡢከ࠸㡿ᇦࡀᒾぢἑ࡟ᐤࡗ࡚࠸ࡿ㸦㸦ᕥᅗ‫ۑ‬‫ۑ‬㸧㸧

5

3-2 2011㸫2012 ෤ᮇ࡜ 2020㸫2021 ෤ᮇࡢẼ㇟࠾ࡼࡧ✚㞷ࡢ㐪࠸2020㸫2021 ෤ᮇ࡟࠾ࡅࡿᒾぢἑ࡛ࡢᖹᆒẼ ࡢ᥎⛣ࢆㄪ࡭㸪Ṕ௦ 1 ఩ࡢ᭱῝✚㞷῝ࢆグ㘓ࡋࡓ 2011㸫2012 ෤ᮇࡢẼ࠾ࡼࡧᖹᖺ್࡜ẚ㍑ࡋࡓ㸦ᅗ 4㸧
ࠋ2011㸫2012 ෤ᮇࡣᖹᖺࡼࡾẼࡀ඲⯡࡟ప࠿ࡗࡓࡢ࡟ᑐࡋ㸪2020㸫2021 ෤ᮇࡣẼ ࡢኚືࡀ኱ࡁࡃ㸪12 ᭶୰᪪࠿ࡽ 1 ᭶ୖ᪪࡟࠿ࡅ࡚ᐮ෭࡛࠶ࡗࡓ୍᪉㸪1 ᭶୰᪪௨㝆ࡣᖹᖺࡼࡾẼࡢ㧗࠸᪥ࡀከ࠿ࡗࡓࠋ⣼✚㝆㞷῝ࢆẚ㍑ࡍࡿ࡜㸪2020㸫2021 ෤ᮇࡣ 2011㸫2012 ෤ᮇ࡜㢮ఝࡋࡓቑຍഴྥࢆぢࡏ㸪グ㘓ⓗ࡞ከ㞷ᖺ࡛࠶ࡗࡓࡇ࡜ࡀ᫂ࡽ࠿࡜࡞ࡗࡓࡀ㸪3 ᭶࡟ධࡿ࡜࡯࡜ࢇ࡝㝆㞷ࡀぢࡽࢀ࡞࠿ࡗࡓࠋ

ᅗ 4
 201
11-2
2012
2 ෤ᮇ࡜
࡜ 2020--2021 ෤ᮇࡢ᪥ᖹᆒẼ࡜⣼⣼ィ㝆㞷῝ࡢẚẚ㍑✚㞷᩿㠃ㄪᰝࡣ 2021 ᖺ 2 ᭶ 16 ᪥㸪2 ᭶ 21 ᪥㸪2 ᭶ 28 ᪥㸪3 ᭶ 5 ᪥ࡢ 4 ᅇ⾜ࢃࢀࡓࠋ2 ᭶୰᪪ࡢᒾぢἑࡢ✚㞷ࡣ㸪౛ᖺ࡛࠶ࢀࡤ⼥㞷ὶฟࡢ๓࡛࠶ࡾ㸪ࡲࡔ஝ࡁ㞷ࡀほࡉࢀࡿ᫬ᮇ࡛࠶

ࡿࠋࡋ࠿ࡋ㸪ᮏ෤ᮇࡢ 2 ᭶ 16 ᪥ࡢ✚㞷ㄪᰝ࡛ࡣ㸪๓᪥࠿ࡽࡢ㝆㞵࡟ࡼࡾ✚㞷ෆ࡟ࡣᖏỈᒙࡀぢࡽࢀࡓࠋᅗ 5a ࡟✚㞷᩿㠃ࢆ♧ࡍࠋࡑࡢ⤖ᯝ㸪㞷 ࡣ඲ᒙ࡛࡯ࡰ 0Υ࡜࡞ࡗࡓ 11)ࠋࡑࡢᚋ 2 ᭶
23 ᪥࠿ࡽ 24 ᪥࡟࠿ࡅ࡚኱㞷࡜࡞ࡗࡓࡢ࡛㸪2 ᭶ 28 ᪥ࡢ✚㞷ㄪᰝ࡛ࡣୖᒙࡢ 50 cm ࡣ 16 ᪥௨㝆ࡢ㝆㞷࠿ࡽ࡞ࡾ㸪஝ࡁ㞷࡛࠶ࡗࡓࠋࡑࡢୗᒙࡢ✚㞷ࡣࡠࢀ㞷ࡢᙳ㡪࡛ࡊࡽࡵ㞷࡬࡜ኚែࡋ࡚࠸ࡓ㸦ᅗ 5b㸧ࠋࡇࢀ࡟ᑐࡋ㸪ᐮ෭ࡔࡗࡓ 2011㸫2012 ෤ᮇࡢ✚㞷ࡣࡋࡲࡾ㞷ࡀ୺య࡛࠶ࡾ஝ࡁ㞷࡛࠶ࡗࡓ㸦ᅗ 5c㸧ࠋ௨ୖࡢࡼ࠺࡟㸪෤ᮇ㛫ࡢᐮᬮࡢ㐪࠸ࡀ㞷㉁࡟㢧ⴭ࡟⌧ࢀࡿ⤖ᯝ࡜࡞ࡗࡓࠋᒾぢἑ࡟࠾ࡅࡿ✚㞷Ỉ㔞㸦✚㞷ࡢỈᙜ㔞㸧ࡢほ ⤖ᯝࢆᅗ 6 ࡟♧ࡍࠋ࠸ࡎࢀࡶ⼥㞷ฟỈ┤๓
ᮇࡢ 2 ᭶ୗ᪪࠿ࡽ 3 ᭶ୖ᪪ࡢ㛫࡟ほ ࡋࡓࡶࡢ࡛࠶ࡿࠋ1978 ᖺ࠿ࡽ 1996 ᖺࡢࢹ࣮ࢱࡣప ⛉Ꮫ㈨ᩱ⦅㸦໭ᾏ㐨኱Ꮫప ⛉Ꮫ◊✲ᡤ㸧࡟ࡼࡿࠋ2012 ᖺ௨㝆ࡣⓑᕝ 7)࡟ࡼࡿࠋ2022 ᖺࡢࢹ࣮ࢱࡣ 3 ᭶ 5 ᪥ࡢほ ⤖ᯝ࡛࠶ࡿࠋ✚㞷῝ࡣ 181 cm㸪✚㞷Ỉ㔞ࡣ 702 mm ࡛࠶ࡗࡓࠋᅗ 6 ࡼࡾ㸪✚㞷Ỉ㔞࡟ࡘ࠸࡚ࡣ 2011㸫2012㸪2020㸫2021 ࡢ࠸ࡎࢀࡶ 700 mm ࢆ㉸࠼࡚࠾ࡾ㸪㐣ཤࡢほࡢᖹᆒ್㸦319 mm㸧࡜ẚ࡭࡚✺ฟࡋ࡚࠸ࡓࠋࡉࡽ࡟㸪┤㏆ 4 ᖺࡣᑡ㞷ᖺࡀ⥆࠸࡚࠸ࡓࡢ࡛㸪ᙜヱᖺࡣࡑࡢ⣙ 2.5 ಸ࠿ࡽ 6 ಸࡢỈ㔞ࡀ✚㞷࡜ࡋ࡚␃ࡲࡗ࡚࠸ࡓࡇ࡜ࡀࢃ࠿ࡿࠋ

6グྕ

㞷㉁

䠇᪂㞷

䠋䛣䛧䜎䜚㞷䖃䛧䜎䜚㞷䕕䛣䛧䜒䛦䜙䜑㞷

䌻䛧䜒䛦䜙䜑㞷

䕿䛦䜙䜑㞷㼂⾲㠃㟖㼕ịᯈ

ᅗ 5 201
11--20112 ෤ᮇ࡜
࡜ 2020--2021 ෤ᮇࡢࡢᒾぢἑ࡟࠾ࡅࡿ✚㞷ᒙᵓ㐀㸦㸦a㸸2021 ᖺ 2 ᭶ 16 ᪥㸪bb㸸2021 ᖺ2 ᭶ 28 ᪥㸪c㸸2012 ᖺ 3 ᭶ 2 ᪥㸬ሙᡤࡣ࠸ࡎࢀࡶ໭
໭ᾏ㐨ᩍ⫱኱Ꮫᒾぢἑᰯࢢࣛ࢘ࣥࢻ࡛ᐇ᪋ࡋࡓ㸧㸧ᅗ 6 ᒾぢἑ࡟࠾ࡅࡿ✚㞷Ỉ㔞ࡢほ⤖ᯝ㸬ほࡣ 2 ᭶ୗ᪪࠿ࡽ 3 ᭶ୖ᪪㸦
㸦1996 ᖺࡲ࡛ࡣప

⛉Ꮫ㈨ᩱ

⦅࡟ࡼࡿ㸬22012 ᖺ௨㝆ࡣⴭ⪅ࡽ 7)࡟ࡼࡿ㸧㸧

7

ᅗ 7 ࡣ኱㞷࡟ぢ⯙ࢃࢀࡓᒾぢἑᕷෆࡢᵝᏊ࡛࠶ࡿࠋ㐨㊰⬥࡟ࡣ㧗ࡉ 3 m ࢆ㉸࠼ࡿ㞷ᒣࡀ㐃⥆ࡋ㸪ࡇࢀ࡟క࠸᭷ຠᖜဨࡀ⊃ࡃぢ㏻ࡋࡀᝏ࠸ࠋ
3-3 ᒾぢἑ࡛㝆㞷ࡀከ࠿ࡗࡓ⌮⏤㏻ᖖ㸪12 ᭶㹼2 ᭶ࡢᒾぢἑࡢ⥲㝆㞷㔞࡜
ᮐᖠ 850hPa㸦ᖹᆒ㧗ᗘ 1,375m㸧Ẽ12᭶㹼2 ᭶ࡢᖹᖺᕪࢆ✚⟬ࡋࡓ್࡜ࡢ㛫࡟ࡣ┦㛵㛵ಀࡀ࠶ࡿ 12)ࠋࡇࢀࡣୗᒙࡢᐮẼ⛣ὶࡀ㝆㞷⌧㇟࡟⤖ࡧࡘࡃࡇ࡜ࢆ♧ࡋ࡚࠸ࡿࠋ
2011㸫2012 ᖺ෤ᮇࡢᒾぢἑࡢ⥲㝆㞷㔞ࡣࡇࡢ㛵ಀࡀᙜ࡚ࡣࡲࡾ㸪ᮐᖠ 850hPa Ẽࡢᖹᖺᕪࢆ✚⟬ࡋࡓ್࡜ࡢ┦㛵ࡀ㧗࠿ࡗࡓࠋࡋ࠿ࡋ 2020㸫2021 ᖺ෤ᮇࡣࡇࡢ㛵ಀ࠿ࡽእࢀ㸪ᮐᖠ 850hPa Ẽ ࡢᖹᖺᕪࡀࡑࢀ࡯࡝ᐮࡃ࡞࠸࡟ࡶ࠿࠿ࢃࡽࡎከ㞷ᖺ࡜࡞ࡗࡓ11)ࠋ
ࡇࡢせᅉࡀ୺࡟໭ᾏ㐨ࡢすᓊ࡟㝆㞷ࢆࡶࡓࡽࡍ㢼ྥࡢ೫ࡾ࡜⪃࠼㸪ᅗ 8 ࡟ 2020㸫
2021 ࡢᮐᖠ㧗ᒙほ850hPa ࡢ㢼ྥࡢฟ⌧ᅗ 7 㝖㞷࡛ᅇᗯࡢࡼ࠺࡟࡞ࡗࡓᒾぢἑᕷෆࡢ㐨㊰⋡ࢆ♧ࡋࡓࠋ᪥ᮏᾏഃᆅᇦࡢ኱㞷ࡣ㸪ᾏ࠿㸦ୖ㸸22021 ᖺ 2 ᭶ 28 ᪥㸬ୗ㸸㸸2021 ᖺ 2 ᭶ 28 ᪥㸧ࡽὶࢀ㎸ࡴ➽≧ࡸᖏ≧ࡢ㞷㞼ࡢิ࡟ࡼࡗ࡚ࡶࡓࡽࡉࢀࡿࡇ࡜࠿ࡽ㸪ୖ✵ 850hPa㸦ᖹᆒ㧗ᗘ 1,375m㸧ࡢ㢼ྥࡣ㞷㞼ࡀὶࢀࡿ᪉ྥࡢ┠Ᏻ࡜࡞ࡿࠋᅗ 8 ࡟ࡼࡿ࡜Ẽࡀᖹᖺ್௨ୗࡢ

᫬ࡢ㢼ྥฟ⌧⋡ࡣ WNW ࡢ㢼ྥࡀ 50%㏆ࡃ࡜༟㉺ࡋ㸪ḟ࠸࡛ W ࡜࡞ࡗ࡚࠸ࡿࠋ඲ᮇ㛫࡛ࡶ
WNW ࡜ W ࡢ㡰࡜࡞ࡗࡓࠋ᪥ᮏᾏ࡛Ⓨ⏕ࡋࡓ㞷㞼ࡣ㸪࿘㎶ࡢᆅᙧ࠿ࡽすᐤࡾࡢ㢼࡛ࡣᒾぢἑ᪉㠃㸪໭ᐤࡾࡢ㢼࡛ࡣᮐᖠ᪉㠃࡟㐍ධࡋ㸪㝆㞷ࡀከࡃ࡞ࡿࡇ࡜ࡀ▱ࡽࢀ࡚࠸ࡿࠋ2020㸫
2021 ෤ᮇࡣᒾぢἑ࡟㞷㞼ࡢ㐍ධࡋࡸࡍ࠸す໭すࡢ㢼ྥࡀ༟㉺ࡋ࡚࠸ࡓࡇ࡜࠿ࡽ㸪ྠࡌᵝ࡞ᐮẼሙ࡛ࡢྠࡌᵝ࡞㞼ࣃࢱ࣮ࣥࡢ᪥ࡀከࡃ㸪኱㞷ࡢせᅉ࡜࡞ࡗࡓࡇ࡜ࢆ♧ࡋ࡚࠸ࡿࠋࡲࡓ㸪ኴᖹὒഃ࡟኱㞷ࢆࡶࡓࡽࡍ㢧ⴭ࡞పẼᅽࡀᑡ

ᅗ 8 ᮐᖠ 850hPa 㢼ྥฟ⌧⋡㸦㸣㸧6)
㸦2020 ᖺ 12 ᭶㹼2021 ᖺ 2 ᭶ࡢ 09 ᫬㸧࡞࠿ࡗࡓࡇ࡜ࡶ㸪ᒾぢἑ࡟኱㞷ࡀ㞟୰ࡋࡓ⫼ᬒ࡜ゝ࠼ࡿࠋ
2020㸫2021 ෤ᮇࡣ 2011㸫2012 ᖺ෤ᮇ 1), 12)࡟ࡶぢࡽࢀࡓࡼ࠺࡞㸪໭ᾏ㐨ࡢすᓊᾏୖࢆ༡ୗ
ࡋ࡚ඛ➃ࡀ໭ᾏ㐨ࡢෆ㝣࡟ධࡾ㎸ࡴᖏ≧㞼ࡸ㸪ἢᾏᕞࡢᒣᓅࡢᙳ㡪ࢆཷࡅࡓᆅᙧᛶ㞼ࣂࣥࢻࡢ8ᅗ 9 2022 ᖺ 2 ᭶ 23 ᪥㹼24 ᪥࡟ᒾぢἑ㸦㸦‫ە‬༳㸧࡬࡬኱㞷ࢆࡶࡓࡽࡋࡓ㞷㞼ࡢ࣮ࣞࢲ࣮࢔࣓ࢲࢫྜᡂᅗ㸬฼฼
ᑼᓥ௜㏆㏆࠿ࡽ༡ୗࡋࡓ㞷㞼࡜኱㝣࠿ࡽࡢ㞷㞼ࡢิࡀ▼⊁‴࡛ྜὶ㸦㸦᪥ᮏẼ㇟༠఍໭ᾏ㐨ᨭ♫ᥦ౪㸧≉ᚩⓗ࡞㞼ࣃࢱ࣮ࣥࡀᒾぢἑ࡟኱㞷ࢆࡶࡓࡽࡋࡓࡇ࡜ࡶ☜ㄆࡉࢀࡓࠋ౛࠼ࡤ㸪᪥㝆㞷㔞ࡀ 50cm
ࢆグ㘓ࡋࡓ 2 ᭶ 24 ᪥ࡣ㸪฼ᑼᓥ௜㏆࠿ࡽすᓊᖏ≧㞼ࡀ༡ୗࡋ㸪ࡑࢀ࡟᪥ᮏᾏ࠿ࡽࡢ➽≧㞼ࡀ▼⊁‴௜㏆࡛㔜࡞ࡗ࡚ᙉ໬ࡉࢀ㸪ᒾぢἑ௜㏆࡟㞟୰ࡋ࡚㝆㞷ࢆࡶࡓࡽࡋ࡚࠸ࡓࡇ࡜ࡀࢃ࠿ࡗࡓࠋ
ᅗ 9 ࡟ 2022 ᖺ 2 ᭶ 23 ᪥ 18 ᫬࠿ࡽ 24 ᪥ 14 ᫬ࡲ࡛ࡢ 4 ᫬㛫ẖࡢ࣮ࣞࢲ࣮࢔࣓ࢲࢫྜᡂᅗࢆ♧ࡍࠋ23 ᪥ 20 ᫬㡭࡟すᓊᖏ≧㞼ࡀⓎ㐩ࡋ࡚໭ᾏ㐨ෆ㝣࡟㐩ࡋ㸪22 ᫬㡭࡟ᒾぢἑ࡟࠿࠿ࡾጞࡵ㸪24 ᪥ 14 ᫬㡭࡟⾶ᙅࡍࡿࡲ࡛ᙉ࠸㝆㞷ࡀ⥅⥆ࡋࡓࡇ࡜ࡀศ࠿ࡿࠋࡇࢀࡣ㐨ኸᅪ࡛ࡢ඾ᆺⓗ࡞኱㞷ࣃࢱ࣮࡛ࣥ࠶ࡗࡓࠋ

94㸬ࡲ࡜ࡵ
2020-2021 ᖺ෤ᮇࡢᒾぢἑࡢ኱㞷ࡢ≉ᚩ࡟ࡘ࠸࡚㸪⌧ᆅ✚㞷ほ ࡜㸪ᆅୖẼ㇟ほ ࢹ࣮ࢱ㸪ゎᯒ✚㞷῝㸪࣮ࣞࢲ࣮࢔࣓ࢲࢫྜᡂᅗ࠾ࡼࡧᮐᖠ㧗ᒙほ850 hPa ࢆ⏝࠸࡚ㄪᰝࢆᐇ᪋ࡋࡓࠋ

᭱኱✚㞷῝ࡣ 2011㸫2012 ᖺ෤ᮇࡢ 208cm ࡟ḟࡄ 205cm ࢆグ㘓ࡋࡓࠋࡲࡓ㸪12 ᭶ࡣ᭶✚㞷᪂グ㘓ࡶ᭦᪂ࡋࡓࠋ2020㸫2021 ᖺ෤ᮇࡢẼ ࡣᖹᖺ୪ࡳ࡛࠶ࡗࡓࡀ㸪᣺ࢀᖜࡀ኱ࡁࡃ㸪1 ᭶୰᪪௨㝆ࡣẼ ࡢ㧗࠸᪥ࡸ㝆㞵ࡀぢࡽࢀࡓࠋࡑࡢᙳ㡪࡛㸪2 ᭶ୗ᪪࠿ࡽ 3 ᭶ୖ᪪ࡢ✚㞷᩿㠃ほ ࡛ࡣ㞷㉁ࡣࡊࡽࡵ㞷ࡀ୺య࡛㸪ᖏỈᒙࡸịᯈࡶ」ᩘ☜ㄆࡉࢀࡓࠋࡇࢀࡣᐮ෭ࡔࡗࡓ 2011㸫2012ᖺ෤ᮇࡢ㞷㉁ࡀࡋࡲࡾ㞷୺యࡔࡗࡓࡇ࡜࡜ᑐ↷ⓗ࡛࠶ࡗࡓࠋᒾぢἑࡢ㝆㞷㔞ࡣ 2011㸫2012 ᖺ෤ᮇ࡟༉ᩛࡍࡿ⣼✚㝆㞷㔞ࢆ♧ࡋ㸪✚㞷Ỉ㔞ࡶ 2011㸫2012ᖺ෤ᮇ࡜ྠ⛬ᗘ࡛࠶ࡗࡓࠋ✚㞷Ỉ㔞ࢆ㐣ཤࡢㄪᰝ⤖ᯝ࡜ẚ㍑ࡍࡿ࡜㸪2020㸫2021 ᖺ෤ᮇࡣ⣙ 2ಸ㸪┤㏆ 4 ෤ᮇ࡜ẚ㍑ࡍࡿ࡜⣙ 2.5 ಸ࠿ࡽ 6 ಸࡢỈ㔞࡛࠶ࡗࡓࠋ㐨ෆࢹ࣮ࢱࢆぢࡿ࡜㸪ࡑࡢ௚ࡢᆅᇦ࡛ࡣᖹᖺࡼࡾࡶᑡ࡞ࡃ㸪ᒾぢἑ࿘㎶ࡢࡳࡀ኱㞷࡟ぢ⯙ࢃࢀࡓࡇ࡜ࡀ᫂ࡽ࠿࡜࡞ࡗࡓࠋ㝆㞷ࡢ≉ᚩࡣ㸪ࡇࡢ෤ࡣすᐤࡾࡢ㢼ࡀ⥅⥆ࡋ㸪ࡑࡢࡓࡵ▼⊁‴࠿ࡽᒾぢἑ᪉㠃࡬㞷㞼ࡀὶࢀࡿ஦㇟ࡀከࡃぢࡽࢀࡓࠋࡉࡽ࡟㸪すᓊᖏ≧㞼ࡀ➽≧ࡢ㞼࡜ྜὶࡋ࡚ᒾぢἑ᪉㠃࡬ὶࢀ㎸ࡴ஦㇟ࡶぢࡽࢀࡓࠋ2020㸫2021 ᖺ෤ᮇࡣẼ ࡀపࡃ࡞ࡃ࡚ࡶᒾぢἑࡀ኱㞷࡟ぢ⯙ࢃࢀࡓ஦౛࡛࠶ࡗࡓࠋ

ㅰ㎡ᮏሗᩥࡣ໭ᾏ㐨ࡢ㞷ị➨ 40 ྕ㸦᪥ᮏ㞷ịᏛ఍໭ᾏ㐨ᨭ㒊㸧࡟ᥖ㍕ࡋࡓ 2021 ᖺᗘ◊✲Ⓨ⾲఍Ⓨ⾲ㄽᩥ 6), 7)ࢆඖ࡟ᇳ➹ࡋࡓࠋᮏ◊✲ࡢ୍㒊ࡣ JSPS ⛉◊㈝ 19K04647 ࠾ࡼࡧ 18K02929 ࡢຓᡂࢆཷࡅᐇ᪋ࡋࡓࠋࡲࡓ㸪✚㞷ㄪᰝ࡟࠾࠸࡚ᒾぢἑᕷ⥲ྜయ⫱㤋࠾ࡼࡧ໭ᾏ㐨ᩍ⫱኱Ꮫᒾぢἑᰯࡢⓙࡉࡲ࡟ࡈ༠ຊ࠸ࡓࡔ࠸ࡓࠋཧ⪃ᩥ⊩(1) 㔠⏣Ᏻᘯ㸪Ọ⏣Ὀᾈ㸪୹἞࿴༤㸪ᯇᒸ┤ᇶ㸪ᑿ㛵ಇᾈ㸸2011-2012 ᖺ෤ᮇ࡟໭ᾏ㐨ᒾぢἑᕷࢆ୰ᚰ࡜ࡋ࡚Ⓨ⏕ࡋࡓ኱㞷࡟ࡘ࠸࡚㸦ࡑࡢ㸯㸧㸫 ኱㞷ࡢᴫせ࡜Ẽ㇟ࡢ≉ᚩ 㸫㸪໭ᾏ㐨ࡢ㞷ị㸪➨ 31
ྕ㸪pp. 115̽118㸪2012㸬(2) 㞷ᐖㄪᰝጤဨ఍㸸≉㞟 ௒෤ࡢ✚㞷࡜㞷ᐖⓎ⏕≧ἣ࡟ࡘ࠸࡚㸦㏿ሗ㸧㸪᪥ᮏ㞷ᕤᏛ఍ㄅ㸪Vol. 37㸪
No. 2㸪pp. 46-50㸪2021㸬
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㸫2012 ᖺ෤ᮇ࡟໭ᾏ㐨ᒾぢἑᕷࢆ୰ᚰ࡜ࡋ࡚Ⓨ⏕ࡋࡓ኱㞷࡟ࡘ࠸࡚㸦ࡑࡢ㸲㸧㸫ᗈᇦ✚㞷ㄪᰝ㸫㸪໭ᾏ㐨ࡢ㞷ị㸪➨ 31 ྕ㸪pp. 127-130㸪2012㸬(6) ᑿ㛵ಇᾈ㸪㔠⏣Ᏻᘯ㸪ᯇᒸ┤ᇶ㸸2020-2021 ᖺ෤ᮇ࡟኱㞷࡟ぢ⯙ࢃࢀࡓᒾぢἑࡢ✚㞷࡜㝆㞷ࡢ≉ᚩ㸪໭ᾏ㐨ࡢ㞷ị㸪➨ 40 ྕ㸪pp.11-12㸪2021㸬
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㸦2021 ᖺ 3 ᭶㸧㸪໭ᾏ㐨ࡢ㞷ị㸪(9) Fierz, C. and 8 others: The International Classification for Seasonal Snow on the Ground,

IHP-VII Technical Documents in Hydrology N83 , IACS Contribution N1, UNESCO-IHP,2009.
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