4ୡ⏺ྛᆅࡢ኱つᶍᔂቯࡢⓎ⏕ศᕸ࣭ᔂቯ≉ᛶ࣭つᶍ‫ۑ‬஬࿡㧗ᚿ࣭ᖹᒸ┿ྜ஀࣭㟷ᡞ୍ᓠ࣭⳥ụிᏊ㸦ᮾி㎰ᕤ኱Ꮫ㸧㸯㸬ࡣࡌࡵ࡟
῝ᒙᔂቯ࡞࡝ࡢᕧ኱ᔂቯࡣࠊ኱つᶍ࡞ᅵ▼ὶࡸኳ↛ࢲ࣒ࡢᙧᡂ࡟ࡘ࡞ࡀࡾࠊ⤖ᯝ࡜ࡋ࡚ୗὶ࡬ࡢ⿕ᐖࡶ኱ࡁࡃ
࡞ࡿഴྥࡀ࠶ࡿࠋᅜෆ࡛ࡣࠊ2011 ᖺ 9 ᭶࡟Ⓨ⏕ࡋࡓ࿴ḷᒣ┴ࡸዉⰋ┴࡛ࡢ⅏ᐖࢆࡣࡌࡵ࡜ࡋ࡚ࠊ῝ᒙᔂቯࢆᑐ㇟࡜ࡋ࡚ࠊࡑࡢⓎ⏕⟠ᡤࠊつᶍࡸ㢖ᗘ࡟㛵ࡍࡿ◊✲ࡀ㐍ࡵࡽࢀ࡚࠸ࡿࠋୡ⏺ྛᆅ࡛ࡶࡇࡢࡼ࠺࡞኱つᶍᔂቯ⌧㇟ࡢⓎ⏕࡜⅏ᐖ࡞࡝࡟ࡘ࠸࡚ሗ࿌ࡉࢀ࡚࠸ࡿ㸦Korup et al., 2007㸧ࠋࡇ࠺ࡋࡓ㏆ᖺࡢ኱つᶍᔂቯࡢⓎ⏕≧ἣࢆホ౯ࡍࡿୖ࡛ࡣࠊ㛗ᮇⓗ࡞Ⓨ⏕ഴྥ࡞࡝ࢆ⥙⨶ⓗ࡟ᢕᥱࡍࡿࡇ࡜ࡀ㔜せ࡛࠶ࡿ࡜ᣦ᦬ࡉࢀ࡚࠸ࡿ㸦ෆ⏣࣭すཱྀ㸪2011㸧ࠋࡑࡇ࡛ࠊᮏ◊✲࡛ࡣࠊୡ⏺ྛᆅࡢ኱つᶍᔂቯࡢⓎ⏕≧ἣࢆᩚ⌮ࡋࠊ኱つᶍᔂቯࡢศᕸ≉ᛶࠊᔂቯᅵ◁㔞࡜ㄏᅉ࡞࡝࡜ࡢ㛵ಀ࡟ࡘ࠸᳨࡚ウࡋࡓࠋᮏ◊✲࡛ࡣࠊ኱つᶍᔂቯࢆᅵ◁⏕⏘㔞ࡀ 105 m3 ௨ୖࡢ⌧㇟࡜ᐃ⩏ࡋࡓࠋ㸰㸬᪉ἲᮏ◊✲ࡣࠊ᪤ ◊✲࡛ሗ࿌ࡉࢀ࡚࠸ࡿࢹ࣮ࢱࢆྲྀ㞟ࡋࠊࢹ࣮ࢱ࣮࣋ࢫ໬ࡍࡿࡇ࡜࡟ࡼࡗ࡚ᐇ᪋ࡋࡓࠋ᪤ ◊✲ࡣࠊᅜෆ࡛ࡣᅵᮌ◊✲ᡤ㸦2010㸧ࠊᾏእ࡛ࡣKorup et al.㸦2007㸧࡞࡝ࡢࣞࣅ࣮ࣗࡀ࠶ࡾࠊࡇࢀࡽࡢࢹ࣮ࢱࢆ୰ᚰ࡜ࡋ࡚
᪂ࡓ࡞ᩥ⊩ࡸሗ࿌᭩࠿ࡽࡢࢹ࣮ࢱࢆ㏣ຍࡋࡓࠋࡇࢀࡲ࡛ࡢ◊✲࡛ࡣ኱つᶍᔂቯࡣᵝࠎ࡞⏝ㄒ࡛ᐃ⩏ࡉࢀ࡚࠾ࡾࠊᮏ
◊✲࡛ࡣࠊᅜෆ࡟࠾ࡅࡿ῝ᒙᔂቯࡸᒣయᔂቯ࡞࡝ࠊᾏእ࡟࠾ࡅࡿlandslideࠊGiantlandslideࠊDeep-seated landslideࠊRockslideࠊCatastrophic landslide࡞࡝ࢆྵࢇ࡛࠸ࡿࠋྛᔂቯࡢⓎ⏕ሙᡤࡢ⦋ᗘ⤒ᗘࠊᅜྡࠊⓎ⏕ᖺ㸦ࡶࡋࡃࡣⓎ⏕ᖺ௦㸧ࠊᔂቯ㠃✚ࠊᔂቯᅵ◁㔞ࠊᔂቯ῝ᗘࠊㄏᅉ㸦ᆅ㟈ࠊ㝆㞵ࠊⅆᒣάື࡞࡝㸧ࢆ࡜ࡾࡲ࡜ࡵࡓࠋࡓࡔࡋࠊୖグࡢ୍㒊ࢹ࣮ࢱࡢࡳࡀグ㍕ࡉࢀ࡚࠸ࡿⓎ⏕஦౛ࡘ࠸࡚ࡶࠊࢹ࣮ࢱ࣮࣋ࢫ࡟ຍ࠼ࡓࠋ㸱㸬኱つᶍᔂቯࡢศᕸ࡜Ⓨ⏕௳ᩘࡢ᥎⛣
ᅗ1࡟ୡ⏺ྛᆅࡢ኱つᶍᔂቯࡢⓎ⏕ศᕸࢆ♧ࡋࡓࠋᅜෆእ࡛921௳ࡢ኱つᶍᔂቯ࡟ࢹ࣮ࢱࢆᚓࡓࠋ኱つᶍᔂቯࡣࠊ
㐀ᒣ㐠ືࡢάⓎ࡞໭༡⡿すᾏᓊࠊࢽ࣮ࣗࢪ࣮ࣛࣥࢻࠊ᪥ᮏࡸᮾ༡࢔ࢪ࢔ࡢ⎔ኴᖹὒᆅᇦࡸࣄ࣐ࣛࣖᒣ⣔ࠊ࣮ࣚࣟࢵࣃ࢔ࣝࣉࢫ࡞࡝ࡢᒣᓅᆅᖏ࡛ศᕸࡋ࡚࠸ࡿഴྥࡀࡳࡽࢀࡓ㸦ᅗ1̺a㸧ࠋᅜෆ࡛ࡣࠊ୰ኸᵓ㐀⥺ἢ࠸ࡢ㏆␥ࠊ୰㒊ᒣᓅࠊ໭㝣ᆅ᪉࡟࠿ࡅ࡚㞟୰ࡋ࡚ศᕸࡋ࡚࠸ࡓ㸦ᅗ1̺b㸧ࠋࡇࢀࡽࡢᆅᇦ࡟࠾ࡅࡿᒣయࡢ㝯㉳㏿ᗘࡣ1㹼5 mm/yr ࡛࠶ࡿ࡜ሗ࿌ࡉࢀ࡚࠾ࡾࠊ᪥ᮏᅜෆࡢ῝ᒙᔂቯࡢศᕸࡀ㝯㉳㔞ࡢከ࠸ᆅᇦ࡟೫ᅾࡋ࡚࠸ࡿࡇ࡜࡜୍⮴ࡍࡿ㸦ෆ⏣࡯࠿㸪
2007㸧ࠋ1800ᖺ௨㝆ࡢ኱つᶍᔂቯࡢグ㘓࡟ࡼࢀࡤࠊᅜෆእ࡜ࡶ࡟1950ᖺ௨㝆ࡢሗ࿌௳ᩘࡀቑ࠼࡚࠸ࡓ㸦ᅗ2㸧ࠋ

(a)

(b)

ᔂቯᅵ◁㔞(m3)<106
106 – 108108 – 1010
> 1010NAᅗ  D ୡ⏺ྛᆅ࡜ E ᅜෆࡢ኱つᶍᔂቯ㸦ᔂቯᅵ◁㔞㸸!P㸧ࡢศᕸ㪄㩷㪙㪄㪉㪋㪉㩷㪄㸲㸬኱つᶍᔂቯࡢⓎ⏕つᶍ࡜ࡑࡢㄏᅉ኱つᶍᔂቯ࡟ࡼࡿᅵ◁⏕⏘㔞ࡢ⟬ฟ࡟ࡣࠊGuzzetti et al.㸦2009㸧࡞࡝࡟ࡼࡿࠊᔂቯ㠃✚࡜ᔂቯᅵ◁㔞ࡢ⤒㦂ᘧࡀά⏝ࡉࢀ࡚࠸ࡿࠋᮏ◊✲࡛ࡣࠊᔂቯᅵ◁㔞ࡀ108 m3 ௨ୗࡢつᶍ࡟ᑐࡋ࡚ࡣࠊࡇࡢ⤒㦂ᘧ࡜ㄪ࿴ⓗ࡞⤖ᯝࡀᚓࡽࢀࡓ㸦ᅗ3̺a㸧ࠋࡋ࠿ࡋ࡞ࡀࡽ109 m3 ௨ୖࡢつᶍ࡟࡞ࡿ࡜ࠊࡇࡢ⤒㦂ᘧ࡛ồࡵࡽࢀࡿᔂቯᅵ◁㔞ࡣ㐣኱ホ౯ࡉࢀࡿഴྥࡀࡳࡽࢀࡓ㸦ᅗ3̺a㸧ࠋᔂቯ࡟ࡼࡿ⏕⏘ᅵ◁㔞ࡣᔂቯ≉ᛶ࡟ࡼࡗ࡚␗࡞ࡿࡇ࡜ࡀᣦ᦬ࡉࢀ࡚࠾ࡾ㸦Larsen et al., 2010㸧ࠊ኱つᶍᔂቯ࡟ࡼࡿ⏕⏘ᅵ◁㔞ࢆホ౯ࡍࡿୖ࡛ࡣࠊᔂቯ㠃✚࡜ᔂቯᅵ◁㔞ࡢ㛵ಀᘧࡢ㐺⏝⠊ᅖࡸண⢭ᗘࢆᢕᥱࡍࡿᚲせࡀ࠶ࡿ࡜⪃࠼ࡽࢀࡓࠋᅜෆእ࡟࠾ࡅࡿᔂቯᅵ◁㔞ࡢつᶍࡈ࡜ࡢሗ࿌௳ᩘࡣࠊᅜෆ࡛ࡣ106737

ᅗ   ᖺ௨㝆ࡢᅜෆእࡢ኱つᶍᔂቯ3

㹼10 m ࠊᾏእ࡛ࡣ10 m ࡢつᶍ࡛㢧ⴭ࡟ࡳࡽࢀࡓ㸦ᅗ3̺b㸧ࠋつ56ሗ࿌௳ᩘࡢ᥎⛣3ᶍࡈ࡜ࡢㄏᅉࡣࠊ㝆㞵࡟ࡼࡿᔂቯࡀ10 㹼10 m ࡢつᶍ࡛ከࡃぢࡽࢀ㸦ᅗ3̺c㸧ࠊ᪤ ࡢ῝ᒙᔂቯࢆྵࡴ኱つᶍᔂቯࡢつᶍ⠊ᅖ࡜୍⮴ࡋ࡚࠸ࡓࠋࡲࡓࠊᆅ㟈ࡼࡿᔂቯࡣ106㹼1010 m3 ࡲ࡛ᖜᗈ࠸つᶍ࡛Ⓨ⏕ࡋ࡚࠾ࡾࠊⅆᒣάື࡟ࡼࡿᔂቯࡣ109 m3 ௨ୖࡢ኱つᶍ࡞ᒣయᔂቯ࡞࡝࡛ሗ࿌ࡉࢀ࡚࠸ࡓ㸦ᅗ3̺c㸧ࠋ㸳㸬ࡲ࡜ࡵ
1.E+13

ࡣࠊ107 m3 ௨ୗࡢつᶍ࡛ࠊ࡭

1.E+12ࡁ஌๎࡜ࡋ࡚ホ౯ࡉࢀ࡚ࡁ

1.E+11ࡓ ࡀ 㸦 ౛ ࠼ ࡤ ࠊ Klar et al.,2012㸧ࠊ௒ᚋࡣᔂቯࡢつᶍࡸᔂቯ≉ᛶ࡟ᛂࡌゎᯒࡍࡿᚲせࡶ࠶ࡿ࡜ᛮࢃࢀࡓࠋࡍ࡞ࢃࡕࠊᑠつᶍ࠿ࡽ኱つᶍᔂቯࢆྵࡵࡓⓎ⏕つᶍࡢ⥙⨶ⓗ࡞ᔂቯᅵ◁㔞:VL(m3)ᔂቯ㠃✚࡜ᅵ◁㔞ࡢ㛵ಀa)ᔂቯ䛾つᶍb)ሗ࿌௳ᩘc)ㄏᅉ

ᾏእᅜෆⅆᒣάື

1.E+10
1.E+09
1.E+08ᆅ㟈

1.E+07
1.E+06
1.E+05㝆㞵VL = 0.074 AL1.45

1.E+04

NAGuzzetti et al. (2009)ศᯒࠊࡉࡽ࡟ࡣ⅏ᐖࡢつᶍ࡞࡝࡟ࡘ࠸࡚ࡶᢕᥱࡍࡿᚲせࡀ࠶ࡿ࡜⪃࠼ࡽࢀࡿࠋࡇࡢࡼ࠺࡞᝟ሗࢆ㞟✚ࠊඹ᭷ࡍࡿࡇ

1.E+03
1.E+02

1.E+04

1.E+06

1.E+08ᔂቯ㠃✚:AL(m2)

1.E+100100

200 0%

௳ᩘ

50%

100%Ⓨ⏕๭ྜᅗ  ኱つᶍᔂቯࡢつᶍࠊⓎ⏕௳ᩘ࡜ࡑࡢㄏᅉ

࡜࡛ࠊᑗ᮶ⓗ࡟◁㜵Ꮫࢆ୰ᚰ࡜ࡋࡓᅜ㝿㐃ᦠࡢࣉࣛࢵࢺࣇ࢛࣮࣒ࢆ⠏ࡅࡿྍ⬟ᛶࡀ࠶ࡿࠋ
ᘬ⏝ᩥ⊩ᅵᮌ◊✲ᡤ ᅵ◁⟶⌮◊✲ࢢ࣮ࣝࣉ ⅆᒣ࣭ᅵ▼ὶࢳ࣮࣒㸦2010㸧Ṕྐⓗ኱つᶍᔂቯࡢᐇែ㸬ᅵᮌ◊✲ᡤ㈨ᩱ➨4169
ྕ㸬218 pp.
Guzzetti F., Ardizzone F., Cardinali M., Rossi M., Valigi D. (2009) Landslide volume and landslide mobilization rate inUmbria, central Italy. Earth and Planetary Science Letters 279: 222-229.
Klar A., Aharonov E., Kalderon-Asael B., Katz O. (2012) Analytical and observational relations between landslides volume
and surface area. Journal of Geophysical Research - Earth Surface 116: DOI: 10.1029/2009JF001604.
Korup O., Clague J.J., Hermanns R.L., Hewitt K., Strom A.L., Weidinger J.T. (2007) Giant landslides, topography, anderosion. Earth and Planetary Science Letters 261: 578–589.
Larsen I.J., Montgomery D.R., Korup O. (2010) Landslide erosion controlled by hillslope material. Nature Geoscience 3:247-251.
ෆ⏣ኴ㑻࣭㕥ᮌ㝯ྖ࣭⏣ᮧᆂྖ㸦2007㸧ᆅ㉁ཬࡧ㝯㉳㔞࡟ᇶ࡙ࡃ῝ᒙᔂቯⓎ⏕༴㝤ᆅᇦࡢᢳฟ㸬ᅵᮌᢏ⾡㈨ᩱ 49㸸
32-37㸬
ෆ⏣ኴ㑻࣭すཱྀᖾᕼ㸦2011㸧Ṕྐⓗ࡟ࡳࡓ㏆ᖺࡢᅵ◁⅏ᐖࡢ≉ᚩ㸬◁㜵Ꮫ఍ㄅ 64㸸58-64㸬㪄㩷㪙㪄㪉㪋㪊㩷㪄