ʴૼɭƴƓƚǔ‫࢟ע‬໎ܹƷȪǹǯ‫҄٭‬Ʊ‫ܖ࢟ע‬Ʒࢫлϋܾ:ŠʴૼɭƴƓƚǔ‫࢟ע‬໎ܹƷཎࣉƱƦƷȪǹǯ‫҄٭‬ƷಒࣞŠ ‫ע‬ᘙᡈͯ‫ؾ‬မ؏ưƷ൦૨‫࢟ע‬ᢅᆉƱƦƷȢȇȫ҄Š ǇƱǊƱʻࢸƷ‫ޒ‬ஓଐஜ‫ܖ࢟ע‬ᡲӳʮᣃ‫᧸ܖٻ‬໎ᄂᆮ৑ ‫ע‬Ⴔ໎ܹᄂᆮᢿᧉ ௅ׄᨺᬱௐ೔‫ט‬ư፭ႆƠƨᘙ‫ْߐޖ‬Ტ2018࠰ग़ۧ‫ܢ‬ԧ޽ᲣʴૼɭƷ‫࢟ע‬໎ܹʴૼɭ: ‫ྶע‬ᘙ‫ޖ‬ǷǹȆȠƷನ঺ᙲእƱƠƯ᫋‫҄נ‬Ơƨʴ᧓‫ח‬ƕᲦଏ‫܍‬Ʒൢ‫ח‬ȷ൦‫ח‬ȷ‫חע‬ȷဃཋ‫ח‬ƱႻʝ˺ဇƢǔྵ‫ע‬ឋ଺ˊᲨ‫࢟ע‬໎ܹ: ‫ם‬ჿᆆѣǛˤƏᐯ໱ྵᝋƱƠƯƷ‫঺࢟࢟ע‬ᢅᆉƷኽௐƱƠƯᲦ‫ئ࢟ע‬Ტԗ‫׊‬Ʒ‫࢟ע‬ႎவˑᲣƴᙹСƞǕƯဃơǔ໎ܹᲨᝍᩋƴǑǔᡈ࠰Ʒ‫࢟ע‬໎ܹƸᲦ‫ם‬ჿƷዅเ؏Ტ̛᫢‫ئ‬ᲣƱᨼᆢ؏Ტ‫ؚ‬ᆢ‫ئ‬Უӑ૾ưƷ࿢‫ؾ‬ો‫٭‬Ტ‫עם‬Мဇ‫҄٭‬ᲣƱᲦʴໝႎƳൢͅ‫٭‬ᛦǛᲦƦǕƧǕእ‫׆‬Ʊᛔ‫׆‬ƷɟᢿƱƠƯႆဃƠƯƍǔᲨʴ߻௎ƔǒƷ්ஙᲢ2017࠰ᅦ‫ޢ‬ஔ̽Უ‫ם‬ჽ්ƴǑǓᘮ໎ƠƨඌᆢᥤɥƷ˰‫עܡ‬Ტ2014࠰࠼޽‫˱ܤ‬Უ࠷ᱫ௎ư፭ႆƠƨᘙ‫ْߐޖ‬Ტ2017࠰ᅦ‫ޢ‬ஔ̽Უ‫࢟ע‬໎ܹȪǹǯƷ‫٭‬ᢟƱசஹᘮܹ࿢‫ؾ‬ો‫٭‬Ტʴ߻௎҄ƱƦƷሥྸ્ూƓǑƼ‫ޛ‬ᰭ‫ؚ‬ᆢ‫࢟ע‬Ʒ‫҄עܡ‬ᲣƱᲦൢͅ‫٭‬ᛦᲢᝍᩋƷᙹ೉ȷ᫁ࡇƷ‫ࢍف‬ᲣƷኽௐᲦүᨖࣱᲢȏǶȸȉᲣƱᏤࢊࣱƷɲ૾ƕ‫ٻف‬ƠᲦᣃࠊԗጂ؏ưƷ‫࢟ע‬໎ܹȪǹǯƕɥଞᲨ‫ͼٻف‬ӼƴƋǔᘮܹǛ᠉ถưƖǔƔƲƏƔƸᲦ໎ܹᢅᆉƷขƍྸᚐƱ‫ܭ‬᣽ႎƳȢȇȫ҄ƴǑǔʖยӧᏡࣱƷྒࢽƴƔƔƬƯƍǔᲨ → ࣏໱ࣱƷਦઇƩƚưƸᚐൿƴƳǒƳƍᲨ?

ᏤࢊࣱӖѣႎᛦԧȷሥྸȷถ໎ᅈ˟ᡈ੗ࣱᲢ୧ᩧᆉࡇᲣ?

଒ஹႎᢸ‫؏עٳ‬ᆢಊႎ᧏ႆȷСࣂȷ᧸໎ᅈ˟ᡈ࠰Ʒက‫ٻ‬໎ܹπя/ᐯяƴǑǓʖยȷ‫ࣖݣ‬ƢǂƖ໎ܹႆᙾƠƯƍƳƍச໎ʙ̊Ტ࿢‫ޓࢼؾ‬ႎȷϘᧈ/ˊஆႎ‫עם‬МဇᲣᆢಊႎᛦԧȷ̬μȷ᭗ࡇ᧸/ถ໎ᅈ˟ྵˊႎᣃࠊԗጂ‫؏ע‬Ტኺฎ၅ࡴȷᢅျ҄ȷ᭗ᱫ҄Უᛔ‫׆‬Ʒᄩྙႎ‫٭‬ѣүᨖࣱʴໝႎൢͅ‫٭‬ᛦƴǑǔ‫٭‬ѣ‫ࠢف‬ငಅ᪃ԡʴૼɭ଺᧓ྵ‫נ‬πя: ȪǹǯǳȟȥȋǱȸǷȧȳȄȸȫƷ੩̓ȷࠝ଺ऴ‫إ‬ႆ̮ᐯя: ɼ˳ႎऴ‫إ‬ӕࢽȷஇᢘᢤᩊƴǑǔʴႎᘮܹ᠉ถ‫࢟ע‬໎ܹƷႆဃƴ᧙ǘǔ‫ע‬ᘙᡈͯ‫ؾ‬မ؏ǷǹȆȠƱƦƷನ঺ᙲእƓǑƼᬝѣೞನ฻๾ภଡ଼࠘Ʒ‫૲עޛ‬᩿ưƸᲦ᫘҄‫ޥ‬Ʊ‫ޖם‬ƔǒƳǔ᫘҄࠘ƱᲦƦǕǛဃ‫ؕ܍‬ႴƱƠƯ঺ᇌƠƨౕ௎ဃ७ኒƕᲦ೔ϛƷ᪬ᢿƔǒᲦᨕ؏൦ࣅ࿢Ʒࢨ᪪ƕƓǑƿ‫ޥ‬ႴϋƷ᫘҄ЭዴƴᐱǔᲦൢ‫ח‬ȷ൦‫ח‬ȷ‫ޥ‬ჽ‫ח‬ȷဃཋ‫ח‬Ʒ‫ע‬ᘙᡈͯ‫ؾ‬မ؏ᲢCritical zoneᲣǛನ঺‫૲עޛ‬᩿ƴƓƚǔcritical zone ǷǹȆȠЭ੩வˑ: ‫ע‬ឋȷ‫࢟ע‬ȷൢͅ଺᧓ǹǱȸȫ105࠰ˌɥ‫؏ע‬ႎƳȆǯȈȋǯǹƱൢͅ‫٭‬ѣ:‫ٳ‬ᢿࢍСщ‫ޥ‬ႴƷཋྸȷ҄‫ܖ‬᫘҄ƴǑǔ᫘҄࠘Ʒႆᢋ:‫ם‬ቩ‫܇‬Ʒဃ঺Ʊ᠞ᡛƴǑǔ‫ޖם‬Ʒ࢟঺:ౕ௎Ʒ঺ᇌƴˤƏౡཋఌኒƷ˦‫ޒ‬:ᨀ൦ƷේᡢƴǑǔ൦Ў‫٭‬ѣ: ϋᢿႻʝ˺ဇ

‫ܭ‬᣽ႎƳʖยȷᚸ̖ƷƨǊƷ࠼޽Ʒᑶ߈‫؏්ޥ‬ƴƓƚǔᘙ‫ْߐޖ‬Ȣȇȫ҄ = ‫ܖ࢟ע‬Ʒࢫл

105–104࠰
103–102࠰
102–100࠰
10−1–10−5࠰ᲢȕǣȸȉȐȃǯᲣλщʴໝႎƳ࿢‫ؾ‬ો‫٭‬/ൢͅ‫٭‬ᛦࣖሉʴૼɭƴƓƚǔ‫࢟ע‬໎ܹ‫עޛ‬Ʒ૲᩿ưƸᲦီƳǔ଺ᆰ᧓ǹǱȸȫưƷλǕ‫܇‬ཞƷ᨞‫ޖ‬ನᡯǛԑƢǔእ‫׆‬வˑƱᛔ‫˺׆‬ဇƷ࠙ኽƱƠƯᲦ‫ם‬ჿᆆѣǛˤƏ‫҄٭࢟ע‬ƕဃơǔᲨʴૼɭƴƓƚǔ‫࢟ע‬໎ܹƷႆဃƸᲦʴໝႎƳჺ஖λщƴ‫ݣ‬ƢǔࣖሉƱਵƑǔƜƱƕưƖǔᲨ

࠯঺30࠰7உᝍᩋƴƓƚǔᨀ൦ཞඞ‫؏්עޛ‬Ʒ൦૨ȷ‫࢟ע‬ᢅᆉภଡ଼฻๾࠘Ʒ‫૲עޛ‬᩿ưƸᲦҾˮፗ᫘҄ƠƨؕႴ‫ޥ‬ᲢǵȗȭȩǤȈᲣǛᲦ‫ם‬ቩ‫܇‬Ʒᨼӳ˳ƔǒƳǔ‫ޖם‬ƕᙴƏᲨ‫ם‬ቩ‫܇‬ƸౡཋఌኒƴǑǓ࣯૲᩿ɥƴ̬ਤƞǕƭƭǋᲦǽǤȫǯȪȸȗƴǑǓዼॸƴᆆѣƠƯ᜿᪽Ї‫ע‬ƴᨼᆢƠƢǔᲨᨀ൦ƸƦƷ‫ٶ‬Ƙƕ‫ע‬ɦƴේᡢƠᲦ‫ٶ‬ಮƳ්ѣኺែƱ๛သ଺᧓ǛኺƯ්ЈǁƱ‫٭‬੭ƞǕǔᲨ੎൦ᏡǛɥ‫ׅ‬ǔᝍᩋ଺Ʒ᧓ᨤ൦‫ן‬ɥଞǛᛔ‫׆‬ƱƢǔᘙ‫ߐޖ‬ْƴǑǓᲦ‫ޖם‬Ƹԗ஖ႎƴ්؏‫ٳ‬ǁƱ੎ЈƞǕǔᲨ

AdoptedfromBierman &Montgomery(2014) Key
Concepts inGeomorphology,
Freeman.

૲᩿ƴƓƚǔ‫ޖם‬ƷႆᢋᨊӊƷǵǤǯȫSoil thicknessRainfall᫘҄࠘Ʒ࢟঺Ʊ൦ࣅ࿢ȷဃཋ෇ѣƷႻʝ˺ဇƕ˺ǓЈƢ‫ע‬ᘙᡈͯ‫ؾ‬မ؏ƴƓƚǔ൦૨‫࢟ע‬ᢅᆉƷወӳႎƳྸᚐƱȢȇȫ҄→ᘙ‫ْߐޖ‬ƷɤᙲእᲢ‫ئ‬৑ȷ଺Цȷᙹ೉Უʖย

Threshold rainfallt
Modified after Iida (1996)

Landslides(D)ȢȇȪȳǰƷ̊: ႆ໎ϐྵᚐௌ(E)᫘҄࠘ƷႆᢋᲦᨀ൦ƷේᡢᲦ‫ޖם‬Ʒ໯ೞȷஊೞႎƳࢍࡇǛᎋॾƠƨ൦૨ȷ‫࢟ע‬ȗȭǻǹȢȇȫƴؕƮƘᘙ‫ْߐޖ‬ȏǶȸȉȞȃȔȳǰ: 2017࠰ʋ߸҅ᢿᝍᩋƴǑǓႆ໎Ơƨᅦ‫ޢ‬ஔ̽Ʒᑶ߈᧋ዯ‫؏්ޥ‬ưƷᚐௌ̊ᲨȢȇȫƷЈщƸᲦᨀᩋȷ‫࢟ע‬ȷౡဃƴ̔‫܍‬ƠƨܱᨥƷႆ໎ཞඞǛϐྵưƖǔ →ʖยӧᏡࣱǛਤƭᲨ(A) Observed landslide scars

50 m(B) Calculated soil thickness(C) Predicted unstable slopes

(D)

(E)

01

2

3

Soil thickness (m)ȢȇȫưƷᘙ‫ْߐޖ‬ƷЎࠋǍဃင‫ם‬ჿ᣽ƕϐྵƞǕƨǱȸǹ: 2017࠰ႆ໎Ʒ҅ʋ߸ஔ̽Ʒ̊ȢȇȫನሰȷܱဇƷȕȬȸȠȯȸǯƱൢͅ‫٭‬ѣᢘࣖǁƷ‫᧏ޒ‬ᘙ‫ْߐޖ‬ƴǑǔ‫ם‬ჿဃငƷʖยȢȇȫƷನሰƱ౨ᚰƓǑƼܱဇ҄ƷȕȬȸȠȯȸǯൿ‫ܭ‬ᛯႎȢȇȪȳǰƴǑǓᲦჺ஖ႎƴƸᲦ˓ॖ්؏ƴƓƚǔ໎ܹʖยǍ‫ם‬ჿဃင᣽Ʒም‫ܭ‬ᲦǇƨᲦʙࢸƷǤșȳȈǢȈȪȓȥȸǷȧȳᚐௌƕܱᘍưƖǔᲨǇƨᲦɶȷᧈ஖ႎƴƸᲦƦǕǛșȸǹƱƠƨᄩྙᛯႎᚸ̖ƴǑƬƯᲦʴໝႎൢͅ‫٭‬ᛦƴˤƏ්؏‫ם‬ჿѣ७Ʒ‫ܾ٭‬ᚸ̖ǛႸਦƢᲨ
(B)

(D)

Sediment yieldwith uncertainty(C)
Probability (%)

101

Sediment yield (m3)Rainfall100

Return period= 10 yr
50 yr

10It will be
shortenedby climatechangeExceeding probability (%)(A)

Rainfall (mm/h)

Rainfall intensity (mm/h)

102

Sediment yield (m3)
100
100

101
Rainfall duration (h)102

time102
103
104
105
106
Sediment yield from watersheds (m3)1ᨀᩋƷឬᢅᄩྙǛ්؏‫ם‬ჿဃင᣽ƷឬᢅᄩྙǁƱ‫٭‬੭Ƣǔ৖᪯Ʒಒࣞ‫׋‬ǇƱǊƱ‫ޒ‬ஓŠ ʴૼɭƷʴໝႎƳ࿢‫ؾ‬ો‫٭‬Ʊൢͅ‫٭‬ᛦƴǑǓᲦᣃࠊԗጂ؏ƴƓƚǔ‫࢟ע‬໎ܹƷүᨖࣱᲢȏǶȸȉᲣȷᡈ੗Ტ୵ᩧᲣࣱȷᏤࢊࣱƕ‫ٻف‬ƠᲦȪǹǯƕɥଞƠƯƍǔᲨŠ ᇌ‫ע‬ᛯƴؕƮƍƯᲦႆ໎Ʒ࣏໱ࣱǛਦઇƢǔƩƚưƸᚐൿƴƳǒƳƍᲨŠ ‫עޛ‬Ʒ૲᩿ưƸᲦ‫ٶ‬ಮƳ଺ᆰ᧓ǹǱȸȫưƷ൦૨ȷ‫࢟ע‬ᢅᆉƕ‫ע‬ᘙᡈͯ‫ؾ‬မ؏ᲢCritical zoneᲣǛ঺ᇌƞƤᲦ‫҄٭࢟ע‬ƴ‫ݣ‬ƠƯλǕ‫܇‬ཞƷ᨞‫ޖ‬ನᡯǛԑƢǔእ‫׆‬வˑƱᛔ‫˺׆‬ဇǛǋƨǒƠƯƍǔᲨʴૼɭƴƓƚǔ‫࢟ע‬໎ܹƷႆဃƸᲦƜƷᐯ໱ǷǹȆȠǁƷʴໝႎƳλщƴ‫ݣ‬Ƣǔჺ஖ࣖሉƱਵƑǔƜƱƕưƖǔᲨŠ ‫࢟ע‬໎ܹƷʖยƴƸᲦ Critical zoneǷǹȆȠƷወӳႎྸᚐƱȢȇȫ҄ƕɧӧഎưƋǓᲦƜǕƕ‫ܖ࢟ע‬ƷࢫлưƋǔᲨȢȇȪȳǰƸ‫ܖ‬ᨥႎӕǓኵǈƴǑƬƯ᭗ࡇ҄ƞǕᲦႆ໎ʙ̊ƴༀǒƠƯ౨ᚰƞǕƭƭƋǔᲨŠ ൿ‫ܭ‬ᛯႎƳ൦૨ȷ‫࢟ע‬ȗȭǻǹȢȇȫƴǑǓᲦჺ஖ႎƴƸᲦ˓ॖ්؏ƴƓƚǔ໎ܹʖยƱ‫ם‬ჿဃင᣽Ʒም‫ܭ‬ǍᲦǤșȳȈǢȈȪȓȥȸǷȧȳƕӧᏡƴƳǔᲨɶȷᧈ஖ႎƴƸᲦƦǕǛșȸǹƱƠƨᄩྙᛯႎᚸ̖ƴǑǓᲦൢͅ‫٭‬ᛦƴˤƏ්؏‫ם‬ჿѣ७Ʒ‫ܾ٭‬ƕ‫ܭ‬᣽ᚸ̖ưƖǔǋƷƱ஖ࢳƞǕǔᲨ්ኚ‫עޛޥ‬ư፭ႆƠƨᘙ‫ْߐޖ‬Ʊ‫ם‬ჽ්Ტ2018࠰࠼޽‫ිܤ‬Უ