IN-STREARM RESTORATION WORK USING TIMBER LOG STRUCTURE IN KAMISAIGO RIVER

(1)

ୖす㒓ᕝ࡟࠾ࡅࡿ㛫ఆᮦࢆ⏝࠸ࡓ Ἑ㐨ෆ⮬↛෌⏕ᕤἲࡢᑟධ࡜ホ౯

IN-STREARM RESTORATION WORK USING TIMBER LOG STRUCTURE IN KAMISAIGO RIVER

ᯘ༤ᚨ

^㻝

䡡᭹㒊ᐇెᏊ

^㻞

䞉᪂ᕼ୍

^㻟

䞉ᒾ℩ᗈ⥅

^㻠

䞉ᓥ㇂ᖾᏹ

^㻡

㻌

Hironori HAYASHI, Mikako HATTORI, Kiichi ARATA, Hirotsugu IWASE, Yukihiro SHIMATANI

1ṇ఍ဨ ᕤ༤ ஑ᕞ኱Ꮫ኱Ꮫ㝔ᕤᏛ◊✲㝔㸦ࠛ814-0395 ⚟ᒸᕷす༊ඖᒸ744㸧

2Ꮫ⏕఍ဨ ஑ᕞ኱Ꮫ኱Ꮫ㝔ᕤᏛᗓ㸦ࠛ814-0395 ⚟ᒸᕷす༊ඖᒸ744㸧

3㠀఍ဨ ⚟ᒸ┴༡⟃ᚋ┴ᅵᩚഛ஦ົᡤ㐨㊰ㄢ㸦ࠛ836-0034 ⚟ᒸ┴኱∹⏣ᕷᑠ὾⏫24-1㸧

4㠀఍ဨ ⚟ᒸᕷ㐨㊰ୗỈ㐨ᒁᘓタ㒊㸦ࠛ810-0001 ⚟ᒸᕷ୰ኸ༊ኳ⚄1-8-1㸧

5ࣇ࢙࣮ࣟ఍ဨ ᕤ༤ ஑ᕞ኱Ꮫ኱Ꮫ㝔ᕤᏛ◊✲㝔㸦ࠛ814-0395 ⚟ᒸᕷす༊ඖᒸ744㸧

The aim of this study is to evaluate in-stream restoration method that made from timber log and rock in Kamisaigo river. We conducted fish sampling survey from 2011 (before restoration) through 2012(after restoration). We also conducted physical environment survey and habitat classification survey to assess the environmental condition change of the stream.

From the result, average fish richness was significantly raised from 2011 to 2012. Also habitat variation and physical environment were diversified by the restoration method (log structure). From an economic point, log structure could be installed without heavy equipment that log structure can be constructed cheaply and conveniently by human power.

Key Words㸸 in-stream restoration, river management, log structure, habitat improvement structure

㸯㸬⫼ᬒ࠾ࡼࡧ┠ⓗ

2006ᖺࡢከ⮬↛ᕝ࡙ࡃࡾࡢ㏻㐩㸪2008ᖺࡢ୰ᑠἙᕝࡢ ᢏ⾡ᇶ‽㸦2010ᖺᨵゞ㸧ࡢไᐃ࡟ࡼࡾ㸪ᮏ㑥࡟࠾ࡅࡿ⎔

ቃ࡟㓄៖ࡋࡓἙᕝᢏ⾡ㄽࡣ୍ᛂࡢయ⣔໬ࡀ࡞ࡉࢀࡓ^1㸧㸬 ࡋ࠿ࡋ࡞ࡀࡽ㸪㒔ᕷἙᕝ࡟௦⾲ࡉࢀࡿ࿘ᅖࡀ㧗ᗘ࡟㛤Ⓨ

ࡉࢀࡓἙᕝ࡛ࡣ㸪⎔ቃ෌⏕ࡢࡓࡵ࡟☜ಖ࡛ࡁࡿ✵㛫ࡀ㝈

ࡽࢀ࡚࠸ࡿࡢ࡛㸪Ἑ㐨ෆ࡛⎔ቃ࡟㓄៖ࡍࡿᢏ⾡ࡀồࡵࡽ

ࢀࡿ㸬ࡇࡢᢏ⾡ࡣ㸪ඛ࡟㏙࡭ࡓᢏ⾡ᇶ‽࡛ࡣゝཬࡉࢀ࡚

࠾ࡽࡎ㸪௒ᚋᢏ⾡ࡢⓎᒎࡀᮇᚅࡉࢀࡿศ㔝࡛࠶ࡿ㸬 ᾏእ࡟࠾࠸࡚ࡣ㸪Ἑ㐨ෆ⮬↛෌⏕ᕤἲࡣ㸪In-stream restoration, Small restoration, Habitat Improvement structures

࡞࡝࡜࿧ࡤࢀ㸪Ḣ⡿ࢆ୰ᚰ࡟ᗈࡃྲྀࡾ⤌ࡲࢀ࡚࠸ࡿ^{2), 3)}㸬 ࡓ࡜࠼ࡤ㸪⮬↛▼ࢆά⏝ࡋࡓⴠᕪᕤࡸ㸪ᮌᮦࢆ฼⏝ࡋࡓ Ỉไ≧ࡢᵓ㐀≀࡞࡝ࡀሗ࿌ࡉࢀ࡚࠸ࡿ^4㸧㸬ࡇࢀࡽࡢᢏ⾡

ࡣ㸪ᮏ㑥࡟࠾࠸࡚ࡶ͆ᑠࡉ࡞⮬↛෌⏕͆ࡸ͇Ἑ㐨ෆ⮬↛

෌⏕͆࡜࿧ࡤࢀ㸪㏆ᖺὀ┠ࢆ㞟ࡵ࡚࠸ࡿ㸬໭ᾏ㐨ࠊᒱ㜧

┴ࠊරᗜ┴ࠊᒣཱྀ┴࡞࡝࡟࠾࠸࡚ඛ⾜஦౛ࡸ◊✲㛤Ⓨࡢ

ྲྀࡾ⤌ࡳ5), 6), 7), 8)ࡀぢࡽࢀࡿࡀ㸪ᢏ⾡ⓗ࡟㛤Ⓨ㏵ୖࡢẁ㝵

࡟࠶ࡾ㸪▱ぢ୙㊊ࡢឤࡣྰࡵ࡞࠸㸬ࡑࡢࡓࡵ㸪ඛ㥑ⓗ࡞

஦౛ࢆ⪃᱌ࡋᑟධࡋ㸪⛉Ꮫⓗ࡟ホ౯ࡍࡿࡇ࡜ࡀồࡵࡽࢀ

ࡿ㸬ᮏ◊✲࡛ࡣ㸪ຠᯝⓗ࡞Ἑ㐨ෆ⮬↛෌⏕ᡭἲࡢ☜❧ࢆ

┠ⓗ࡜ࡋ࡚㸪⚟ᒸ┴ࡢୖす㒓ᕝ࡟࠾࠸࡚㸪㛫ఆᮦ➼ࡢᆅ ሙᮦࢆά⏝ࡋࡓἙ㐨ෆ⮬↛෌⏕ᕤἲࢆ㛤Ⓨ࣭ᑟධࡋ㸪ࡑ ࡢຠᯝ࡟ࡘ࠸࡚ホ౯ࡋࡓ⤖ᯝࢆሗ࿌ࡍࡿ㸬

㸰㸬◊✲ᑐ㇟ᆅࡢᴫせ

ᮏ◊✲ࡢᑐ㇟ᆅࡣ㸪⚟ᒸ┴⚟ὠᕷࢆὶࢀࡿ஧⣭Ἑᕝす㒓ᕝࡢᨭᕝୖす㒓ᕝ࡛࠶ࡿ㸦ᅗ㸧㸬ୖす㒓ᕝ࡛ࡣ㸪୰ᑠ Ἑᕝࡢᢏ⾡ᇶ‽࡟ᚑࡗࡓከ⮬↛ᕝ࡙ࡃࡾࡀྲྀࡾ⤌ࡲࢀ࡚

࠾ࡾ㸪 ᖺ࠿ࡽẁ㝵ⓗ࡟᪋ᕤࡉࢀ࡚࠸ࡿ㸬࡞࠾㸪ከ⮬

↛ᕝ࡙ࡃࡾࡀྲྀࡾ⤌ࡲࢀ࡚࠸ࡿࡢࡣ㸪Ἑᗋ໙㓄ࡀ 㹼 ࡢᘏ㛗⣙ ੊ࡢ༊㛫࡛࠶ࡿ㸬ᢏ⾡ᇶ‽^1㸧ࢆ㋃く ࡋ࡚࠸ࡿ࣏࢖ࣥࢺ࡜ࡋ࡚ࡣ㸪ᕝᖜࢆᣑᖜࡍࡿࡇ࡜࡛Ἑ✚

ࢆ☜ಖࡋἙᗋ᥀๐ࢆᇶᮏⓗ࡟⾜ࢃ࡞࠸ࡇ࡜ࡸ㸪ᕝࡢኚ໬

ࢆチᐜࡋ⮬↛࡞Ἑᓊ࣭Ỉ㝿ࢆᙧᡂࡉࡏࡿࡇ࡜㸪ⴠᕪᕤ➼

ࡣᚲせ᭱ᑠ㝈࡟␃ࡵ㸪ᚲせ࡞ಶᡤ࡟ࡘ࠸࡚ࡶ⦪᩿᪉ྥࡢ ⴠᕪࢆᴟຊ⦆࿴ࡍࡿࡇ࡜㸪ᩚഛᚋࡢ⥔ᣢ⟶⌮ࡲ࡛ど㔝࡟

ධࢀࡓィ⏬࡜ࡍࡿࡇ࡜࡞࡝ࡀ࠶ࡆࡽࢀࡿ㸬

ୖす㒓ᕝ࡟࠾ࡅࡿከ⮬↛ᕝ࡙ࡃࡾࡢ᭱኱ࡢ≉ᚩࡣ㸪ᢏ

(2)

ᅗ 㛫ఆᮦỈไࡢ᪋ᕤ

⾡ᇶ‽࡛ࡣゝཬࡉࢀ࡚࠸࡞࠸Ἑ㐨ෆ⮬↛෌⏕ᡭἲࢆヨ㦂

ⓗ࡟ᑟධࡍࡿࡇ࡜࡟ࡼࡾ㸪㐣ཤࡢᨵಟ࡛༢ㄪ໬ࡋࡓ℩ῡ

⎔ቃࢆ෌⏕ࡍࡿᕤኵ⾜ࡗ࡚࠸ࡿⅬ࡛࠶ࡿ㸬ࡲࡓ㸪ከ⮬↛

ᨵಟᚋࡶࣔࢽࢱࣜࣥࢢࢆᐇ᪋ࡋ࡞ࡀࡽ㸪㡰ᛂⓗ࡟Ἑ㐨ෆ

⮬↛෌⏕ᡭἲࢆᑟධࡍࡿࡇ࡜࡟ࡼࡾ㸪Ἑ㐨ෆࡢ⎔ቃᨵၿ

࡟ྲྀ⤌ࢇ࡛࠸ࡿⅬࡶ኱ࡁ࡞≉ᚩ࡛࠶ࡿ㸬ᮏㄽ࡛ᑐ㇟࡜ࡍ

ࡿ㛫ఆᮦࢆά⏝ࡋࡓἙ㐨ෆ⮬↛෌⏕ᕤἲࡣ㸪ୖす㒓ᕝ࡟

࠾ࡅࡿ㡰ᛂⓗ࡞⟶⌮ࡢ୍⎔࡜ࡋ࡚ᑟධࡉࢀࡓࡶࡢ࡛࠶ࡿ㸬

㸱㸬Ἑ㐨ෆ⮬↛෌⏕ᕤἲࡢ⪃᱌࡜ᑟධ

㸦1㸧㛫ఆᮦࢆ⏝࠸ࡓἙ㐨ෆ⮬↛෌⏕ᕤἲ࡟ࡘ࠸࡚

ᮏㄽ࡛ᑐ㇟࡜ࡍࡿἙ㐨ෆ⮬↛෌⏕ᕤἲࡣ㸪㛫ఆᮦ࡜⮬

↛▼ࢆά⏝ࡋ࡚సᡂࡋࡓỈไ≧ࡢᵓ㐀≀࡛㸪㛫ఆᮦỈไ

࡜࿧ࡪ㸦ᅗ㸧㸬ᮏᕤἲࡣ㸪Ḣ⡿࡟࠾ࡅࡿඛ㐍஦౛^4㸧ࡸ㸪 ᮏ㑥ࡢ▼⤌ࡳᕤἲ^9㸧㸪࠾ࡼࡧୖす㒓ᕝ⌧ᆅࡢ≧ἣ࡞࡝ࢆ

ཧ⪃࡟ᙧ≧ࡸ᪋ᕤ఩⨨ࢆỴᐃࡋࡓ㸬

㸦2㸧㛫ఆᮦỈไࡢᇶᮏⓗ࡞⪃࠼᪉

㛫ఆᮦỈไࡣ㸪ᕝࡢ୰ࡢỈࡢὶࢀࡸἙᗋࡢ≧ἣ࡞࡝ࢆ

ከᵝ࡟ࡍࡿࡇ࡜ࢆ┠ⓗ࡜ࡋ࡚ᑟධࡋࡓ㸬タ⨨ࡍࡿྥࡁ㸦ὶ

ୗ᪉ྥ࡟ᑐࡋ࡚ୖྥࡁ࠿ୗྥࡁ㸧࡟ࡼࡗ࡚㸪ᶵ⬟ࡣከᑡ

␗࡞ࡿࡶࡢࡢ㸪㛫ఆᮦࢆ⏝࠸ࡓ୸ኴ࡜▼ᮦࢆ⤌ࡳྜࢃࡏ

ࡿࡇ࡜࡟ࡼࡾ㸪Ỉไ≧ࡢᵓ㐀≀ࢆసᡂࡋ㸪Ỉࡢὶ࡟ࡼࡗ

࡚Ἑᕝࡢ⎔ቃࢆከᵝ࡟ࡍࡿࡇ࡜ࢆ᝿ᐃࡋ࡚࠸ࡿ㸬࡞࠾㸪㛫ఆᮦỈไ࡟ᮇᚅࡍࡿᶵ⬟࡜ࡋ࡚ࡣ㸪ձὶࢀࡢከᵝ໬࣭

」㞧໬㸦᪩࠸ὶࢀ࡜㐜࠸ὶࢀࡢ࣓ࣜࣁࣜࢆࡘࡅࡿ㸧㸪ղἙ ᅗ ◊✲ᑐ㇟ᆅࡢ఩⨨

ᅗ 㛫ఆᮦỈไ

ୖὶྥࡁỈไ ୗὶྥࡁỈไ ᖹᖖ᫬࣭ὥỈ᫬ࡢὶࢀࢆከᵝ࡟ࡍࡿ

㸦℩㸪ῡ㸪ࡼ࡝ࡳࢆᙧᡂ࣭ᅵ◁ࡢศ⣭㸧

▼ᮦ࠾ࡼࡧ୸ኴ࡟ࡼࡾᙧᡂࡉࢀࡿ✵㝽ࡢ๰ฟ

ୖὶྥࡁ ୗὶྥࡁ

࣭ὶࢀࢆᑐᓊഃ࡟ࡣࡡࡿ

࣭ୗὶ࡟ῡࢆᙧᡂ

࣭ୖὶ࡟◁ᕞࢆᙧᡂ

࣭ὶࢀࢆ⮬ᓊഃ࡟ࡣࡡࡿ

࣭ୗὶ࡟࣡ࣥࢻ㸦ࡼ࡝ࡳ㸧

ࢆᙧᡂ

ᅗ㛫ఆᮦỈไࡢᇶᮏⓗ࡞ᶵ⬟

P ⛬ᗘ

Ỉࡢὶࢀ

ᆅ┙ ᆅ┙

ᅗ 㛫ఆᮦỈไࡢᵓ㐀ࢫࢣࢵࢳ

㸦Ἑ㐨ᶓ᩿᪉ྥ㸹ୗὶഃ࠿ࡽぢࡓᅗ㸧

P ⛬ᗘ

Ỉࡢὶࢀ

ᆅ┙

ᅗ 㛫ఆᮦỈไࡢᵓ㐀ࢫࢣࢵࢳ㸦Ἑ㐨ὶ⥺᪉ྥ㸧

(3)

ᗋᮦᩱࡢศ⣭㸪ճ▼ᮦ࠾ࡼࡧ୸ኴ࡟ࡼࡾᙧᡂࡉࢀࡿ✵㝽 ࡢ๰ฟ࡞࡝ࡀ࠶ࡿ㸦ᅗ㸧㸬㛫ఆᮦỈไࡣ㸪Ỉ㝿࠿ࡽὶᚰ

ഃ࡟ྥ࠿ࡗ࡚㸪ᖹᖖ᫬ࡢỈ㠃ᖜࡢ 㹼 ⛬ᗘᙇࡾฟࡉ ࡏࡿࡇ࡜࡜ࡋ㸪ὶ⥺᪉ྥ࡟ᑐࡋ࡚ 㹼r⛬ᗘࡢഴࡁࢆ

ᣢࡓࡏ࡚タ⨨ࡋࡓ㸬タ⨨ࡍࡿྥࡁࡣ㸪ୖὶഃࢆྥ࠿ࡏࡿ

ࡶࡢ࡜㸪ୗὶഃࢆྥ࠿ࡏࡿࡶࡢ࡜ࡢ ㏻ࡾࢆ㸪ୖす㒓ᕝ

⌧ᆅࡢ⃢➽ࡸἙᓊࡸ◁ᕞࡢ≧ἣࢆぢ࡞ࡀࡽ㸪㐺ษ࡞ྥࡁ

ࡸሙᡤࢆุ᩿ࡋタ⨨ࡋࡓ㸬

㸦3㸧㛫ఆᮦỈไࡢᵓ㐀

㛫ఆᮦỈไࡢᵓ㐀ᅗࡢࢫࢣࢵࢳࢆᅗ㸪ᅗ࡟♧ࡍ㸬

⏝࠸ࡓ㛫ఆᮦࡣ㸪㍺㏦ࡢ฼౽ᛶ㸦୍⯡චチ࡛㍺㏦ྍ⬟࡞

W ࢺࣛࢵࢡࡢⲴྎࡀ P ࡛࠶ࡿ㸧➼ࢆ⪃៖ࡋ㸪୍ࡘࡢ㒊ᮦ

ࡢ㛗ࡉࢆ P ⛬ᗘ࡜ࡋࡓ㸦ᅗ㸧㸬ࡲࡓ㸪㛗ࡉ P ࡢ㕲➽ࢆ

㛫ఆᮦ㸦୸ኴ㸧࡟㝗ධࡉࡏ㸪㛫ఆᮦࢆᆅ┙㠃࡟ᅛᐃࡍࡿ

ᵓ㐀࡜࡞ࡗ࡚࠸ࡿ㸬࡞࠾㸪㕲➽ࡣ㖄┤᪉ྥ࡟ᑐࡋ࡚㸪r

⛬ᗘഴࡅ࡚㸪㹼P 㛫㝸࡛ࢪࢢࢨࢢ࡟㝗ධࡍࡿࡇ࡜࡟ࡼ

ࡾ㸪ᙉᅛ࡟ᆅ┙㠃࡟ᅛ╔ࡍࡿࡼ࠺㓄៖ࡋࡓ㸬ࡉࡽ࡟㸪୸

ኴࡢᚋࢁୖ㠃࡟ȭ㹼 ੉⛬ᗘࡢ▼ᮦࢆ⤌ࡳྜࢃࡏ࡚タ

⨨ࡍࡿࡇ࡜࡟ࡼࡾ㸪୸ኴࡢᏳᐃཬࡧ✵㝽ࡢ๰ฟࢆᅗࡗ࡚

࠸ࡿ㸦ᅗ㸧㸬࡞࠾㸪▼ࡢ⤌ࡳ᪉ࡸྥࡁ࡟ࡘ࠸࡚ࡣ㐣ཤ࡟

ሗ࿌ࡉࢀ࡚࠸ࡿ▼⤌ࡳᕤἲ^9㸧ࢆཧ⪃࡟ࡋࡓ㸬㸦4㸧㛫ఆᮦỈไࡢ᪋ᕤ

㛫ఆᮦỈไࡢ᪋ᕤ࡟㝿ࡋ㸪ᚲせ࡞୺࡞ᮦᩱࡣ㸪୸ኴ㸦㛫 ఆᮦ㸧㸪▼ᮦ㸪㕲➽ࡢ ࡘ࡛࠶ࡿ㸬୸ኴ࡟ࡘ࠸࡚ࡣ㸪㏆㞄

ὶᇦ࡛Ⓨ⏕ࡋࡓ㛫ఆᮦࢆά⏝ࡋࡓ㸬▼ᮦ࡟ࡘ࠸࡚ࡣ㸪す㒓ᕝὶᇦ࡟࠾ࡅࡿᕤ஦࡛Ⓨ⏕ࡋࡓࡶࡢࢆά⏝ࡋࡓ㸬㕲➽

࡟ࡘ࠸࡚ࡢࡳ㸪᪂ࡓ࡟㉎ධࡋࡓࡶࡢࢆ⏝࠸ࡓ㸬

᪋ᕤ࡟ࡘ࠸࡚ࡣ㸪ୖす㒓ᕝ࡛ྲྀࡾ⤌ࢇ࡛࠸ࡿᕷẸཧຍ ࡢᕝ࡙ࡃࡾࡢྲྀࡾ⤌ࡳࡢ୍⎔࡜ࡋ࡚ᐇ᪋ࡋ㸪஑ᕞ኱Ꮫࡢ Ꮫ⏕ཬࡧᩍ⫋ဨ㸪⾜ᨻ⫋ဨ㸪ἢᕝఫẸࡢ༠ാ࡛⾜ࡗࡓ㸬

᪋ᕤ᫬ࡢᵝᏊࢆ㸦ᅗ㸧࡟♧ࡍ㸬᪋ᕤᡭ㡰࡜ࡋ࡚ࡣ㸪ึ

ࡵ࡟᪋ᕤ఩⨨ࢆỴᐃࡋ㸪ᆅᙧ࡟ྜࢃࡏ࡚୸ኴࢆタ⨨ࡋࡓ㸬 ࡑࡢᚋ㸪୸ኴ࡟㕲➽ࢆᡴࡕ㎸ࡴࡓࡵࡢ✰࠶ࡅ㸪㕲➽ࢆᡴ ࡕ㎸ࡳ୸ኴࢆᆅ┙㠃࡟ᅛᐃࡋࡓ㸬᭱ᚋ࡟㸪୸ኴࡢᚋࢁୖ

㠃࡟▼ᮦࢆ⤌ࡳྜࢃࡏ࡚㍕ࡏ㸪୸ኴࢆᏳᐃࡉࡏࡓ㸬࡞࠾㸪 ௨ୖࡢసᴗࡣࡍ࡭࡚ேຊ࡛⾜ࡗࡓ㸬㛫ఆᮦࡢ᪋ᕤసᴗࡣ ᖺ ᭶࡟⾜ࡗࡓ㸬

㸲㸬㛫ఆᮦỈไᑟධຠᯝࡢ᳨ド

㸦1㸧ㄪᰝ᪉ἲ

㛫ఆᮦỈไࡢຠᯝࢆ᳨ドࡍࡿࡓࡵ࡟㸪ࣁࣅࢱࢵࢺኚ໬㸪㨶㢮⏕ᜥ≧ἣ㸪≀⌮⎔ቃኚ໬࡟ࡘ࠸࡚ㄪᰝࢆ⾜ࡗࡓ㸬ᑐ

㇟Ἑᕝෆ࡟ᘏ㛗 P ࡢㄪᰝ༊㸦㨶㢮ㄪᰝ࡛ࡣ P ࢆࡉࡽ

࡟ ࡘࡢࣈࣟࢵࢡ࡟ศ๭㸧ࢆ㸪㛫ఆᮦᑟධ༊࡜ẚ㍑ᑐ↷

༊㸦㛫ఆᮦࢆᑟධࡋ࡞࠸༊㸧࡟ࡘ࠸࡚㸪ࡑࢀࡒࢀ ༊㛫 ࡎࡘタࡅ㸪ࡑࢀࡒࢀࡢㄪᰝ༊࡛ྠෆᐜࡢㄪᰝࢆ⾜ࡗࡓ㸬ㄪᰝᮇ㛫ࡣ㸪ᑟධ๓㸦 ᖺ㸧㸪ᑟධᚋ㸦 ᖺ㸧ࡢ

࢝ᖺ㛫࡜ࡋ㸪ㄪᰝࡣྛᖺ࡜ࡶ࡟᫓ኟ⛅㸦ࣁࣅࢱࢵࢺኚ໬

ᑐ↷༊ࡢᬒほ

ᅗ ㄪᰝࢹࢨ࢖ࣥ㸦᪋ᕤ๓ᚋ࡛㛫ఆᮦᑟධ༊࡜ᑐ↷༊࡜ࢆẚ㍑ࡍࡿ %$&, ࢹࢨ࢖ࣥ㸧㛫ఆᮦᑟධ༊ࡢᬒほ

(4)

ࡢࡳྛᖺ ᅇ㸧࡟ᐇ᪋ࡋࡓ㸦ィ ᅇ㸧㸬ᅗ࡟ㄪᰝࢹࢨ࢖

ࣥᅗࢆ♧ࡍ㸬

Dࣁࣅࢱࢵࢺ༊ศㄪᰝ

ᑐ㇟༊㛫ࡢ⎔ቃࢆ㸪ᬒほⓗ≉ᚩࢆࡶ࡜࡟㸪᪩℩࣭ᖹ℩࣭

࡜ࢁ࣭ࡼ࡝ࡳ࣭ῡࡢ ࡘࡢࣁࣅࢱࢵࢺ࡟ศ㢮ࡋ㸪⌧ᆅ㋃

ᰝ࡟ࡼࡾㄪᰝᑐ㇟༊㛫ࡢࣁࣅࢱࢵࢺ࣐ࢵࣉࢆసᡂࡋࡓ㸬

࡞࠾㸪ᮏㄽ࡛ᐃ⩏ࡍࡿࣁࣅࢱࢵࢺࡢ≉ᚩࢆ⾲࡟♧ࡍ㸬 E㨶㢮ㄪᰝ

㨶㢮ࡢ᥇ᤕ࡟ࡣ࢚ࣞࢡࢺࣜࢵࢡࢩࣙࢵ࣮࢝ࢆ⏝࠸ࡓ㸬

ࣈࣟࢵࢡࢿࢵࢺࢆ⏝࠸࡚ྛㄪᰝ༊ࢆ ࡘࡢࣈࣟࢵࢡ࡟ศ ࡅ㸪ࣁࣅࢱࢵࢺࡈ࡜࡟⏕ᜥࡋ࡚࠸ࡿ㨶✀ࢆ᥇ᤕࡋࡓ㸬᥇ ᤕࡋࡓ㨶㢮ࡢ㨶✀࣭ᶆ‽య㛗ࢆグ㘓ࡋࡓࡢࡕ㸪㏿ࡸ࠿࡟

ᨺὶࡋࡓ㸬 F≀⌮⎔ቃㄪᰝ

ྛㄪᰝ༊ෆ࡛㸪ࣁࣅࢱࢵࢺࡈ࡜ࡢỈ῝࣭ὶ㏿࣭Ỉ㠃ᖜ࣭

ィ Ⅼ┿ୗࡢἙᗋᮦᩱࢆィ ࡋࡓ㸬 Ⅼࡣྛࣁࣅࢱࢵࢺ ࡢᶓ᩿᪉ྥ࡟ Ⅼタࡅࡓ㸬ࣁࣅࢱࢵࢺࡢ⦪᩿ᘏ㛗ࡀỈ㠃 ᖜࢆ㉸࠼ࡿሙྜࡣ㸪ഃ⥺ࢆ㏣ຍࡋィ ࡋࡓ㸬

㸦2㸧ㄪᰝ⤖ᯝ

Dࣁࣅࢱࢵࢺ༊ศㄪᰝ

ࣁࣅࢱࢵࢺ༊ศㄪᰝ⤖ᯝࡢࣁࣅࢱࢵࢺ࣐ࢵࣉࢆᅗ࡟

♧ࡍ㸬ᑐ↷༊࡟࠾࠸࡚ࡣ㸪 ᖺ࡜ ᖺ࡜࡛኱ࡁ࡞ࣁ

ࣅࢱࢵࢺࡢኚ໬ࡣぢࡽࢀࡎ㸪୺࡟࡜ࢁࡢὶࢀ࡜࡞ࡗ࡚࠾

ࡾ㸪ῡ㸪ࡼ࡝ࡳࡀ☜ㄆ࡛ࡁࡿ㸬୍᪉㸪㛫ఆᮦᑟධ༊࡟࠾

࠸࡚ࡣ㸪 ᖺࡣᑐ↷༊࡜ྠᵝ࡟࡜ࢁࡢὶࢀࡀᨭ㓄ⓗ࡛

࠶ࡗࡓࡀ㸪 ᖺ㸦㛫ఆᮦỈไᑟධᚋ㸧࡟ࡣ㸪᪂ࡓ࡟ᖹ

℩ࡀ☜ㄆࡉࢀ㸪ῡࡢ㠃✚ࡸࡼ࡝ࡳࡢ㠃✚๭ྜࡀቑ኱ࡋ㸪

ࣁࣅࢱࢵࢺࡀከᵝ࡟࡞ࡗࡓᵝᏊࡀ☜ㄆࡉࢀࡓ㸬≉࡟㸪㛫 ఆᮦỈไࢆᑟධࡋࡓ⟠ᡤࡢ࿘㎶࡟ࡣ㸪୸ኴࡢඛ➃࡟ῡࡀ ᙧᡂࡉࢀ㸪୸ኴࡢ௜ࡅ᰿ࡸ୸ኴタ⨨ሙᡤࡢᑐᓊഃ࡟᪂ࡓ

࡟ࡼ࡝ࡳࡀᙧᡂࡉࢀࡿ࡞࡝ࡢኚ໬ࡀ☜ㄆࡉࢀࡓ㸬ࡇࢀࡽ

ࡣ㸪㛫ఆᮦỈไࡢᑟධ࡟ࡼࡗ࡚ࡶࡓࡽࡉࢀࡓࡶࡢ࡜ᛮࢃ

ࢀࡿ㸬

E㨶㢮ㄪᰝ

ᖺ㛫ィ ᅇࡢㄪᰝ࡟ࡼࡾ㸪ィ ✀ ಶయࡢ㨶㢮ࡀ ᥇ᤕࡉࢀࡓ㸬ㄪᰝ⤖ᯝࢆ⾲࡟♧ࡍ㸬࡞࠾㸪⾲࡟ࡣ㸪㐣ཤ࡟す㒓ᕝỈ⣔࡛➹⪅ࡽࡀ⾜ࡗࡓㄪᰝ㸦ᮍⓎ⾲㸧࡛ࡇ

ࢀࡲ࡛☜ㄆࡉࢀࡓࡍ࡭࡚ࡢ✀㸦඲✀㸧ࢆᥖ㍕ࡋ࡚࠸ࡿ㸬 Ἑᕝ୰ὶᇦ࡟୍⯡ⓗ࡟ࡳࡽࢀࡿ㨶✀ࡀ୰ᚰ࡟ฟ⌧ࡋ㸪ࢽ

࣍ࣥ࢘ࢼࢠ㸦⤯⁛༴᝹Ϩ% 㢮㸧㸪࣐ࣖࢺࢩ࣐ࢻࢪࣙ࢘㸦⤯

⁛༴᝹ϩ㢮㸧࡞࡝⎔ቃ┬ࡢࣞࢵࢻࣜࢫࢺ࡟ᥖ㍕ࡉࢀ࡚࠸

ࡿᕼᑡ✀ࡶ☜ㄆࡉࢀࡓ㸬

⥆࠸࡚㸪ᅗ࡟ᖹᆒฟ⌧✀ᩘ㸪ᅗ࡟ᖹᆒ᥇ᤕಶయ

ᩘࢆ♧ࡍ㸬ᑐ↷༊㸪㛫ఆᮦᑟධ༊࡜ࡶ࡟㸪✀ᩘ࡟ࡘ࠸࡚

ࡣ ᖺ࠿ࡽ ᖺ࡟࠿ࡅ࡚᭷ព࡟ቑຍ㸦S7 WHVW㸧ࡋ㸪ಶయᩘ࡟ࡘ࠸࡚ࡣ᭷ពᕪ࡞ࡋ࡜࠸࠺⤖ᯝ࡜࡞

ࡗࡓ㸬

F≀⌮⎔ቃㄪᰝ

ᅗ࡟ὶ㏿Ỉ῝ࡢࣉࣟࢵࢺࢆ♧ࡍ㸬ᑐ↷༊࡟࠾࠸࡚

ࡣ㸪ὶ㏿࠾ࡼࡧỈ῝ࡢศᕸ⠊ᅖࡣ㸪ὶ㏿ࡀ 㹼 ੉V ⛬ ᗘ㸪Ỉ῝ࡀ 㹼 ੉⛬ᗘ࡜࡞ࡗ࡚࠾ࡾ㸪 ᖺ࡜

ᖺ࡜ࡢ㛫࡛኱ࡁ࡞ኚ໬ࡣぢࡽࢀ࡞࠸㸬୍᪉㸪㛫ఆᮦỈไ ᑟධ༊࡟࠾࠸࡚ࡣ㸪 ᖺ࠿ࡽ ᖺ࡟࠿ࡅ࡚ὶ㏿㸪Ỉ

῝࡜ࡶ࡟ศᕸᇦࡢᖜࡀᣑ኱ࡋࡓࡇ࡜ࡀ☜ㄆ࡛ࡁࡿ㸬ὶ㏿

ࡀ 㹼 ੉VЍ㹼 ੉V ⛬ᗘ࡟࡞ࡾ㸪Ỉ῝ࡀ 㹼 ੉ Ѝ㹼 ੉⛬ᗘ࡟ศᕸᇦࢆᣑ኱ࡋࡓ㸬ࡇࡢ⤖ᯝࡣ㸪ࣁࣅࢱ

ࢵࢺ༊ศㄪᰝ࡟࠾࠸࡚ᚓࡽࢀࡓࡼ࠺࡟㸪㛫ఆᮦỈไᑟධ

༊࡛ࡣ᪂ࡓ࡟℩ࡸῡࡀ๰ฟࡉࢀࡓ࡜࠸࠺ࡇ࡜ࢆ཯ᫎࡋ࡚

࠸ࡿࡶࡢ࡜ᛮࢃࢀࡿ㸬

ᅗ࡟Ỉ㠃ᖜἙᗋᮦᩱ⢏ᚄࡢࣉࣟࢵࢺࢆ♧ࡍ㸬ᑐ↷

༊࡜㛫ఆᮦỈไᑟධ༊ࡢ୧᪉࡟࠾࠸࡚ ᖺ࠿ࡽ

ᖺ࡟࠿ࡅ࡚Ỉ㠃ᖜࡢ⦰ᑠࡀ☜ㄆࡉࢀࡓ㸬ࡇࢀࡣ㸪 ᖺ

࡟ᐇ᪋ࡉࢀࡓἙᕝᨵಟᚋ࡟Ἑ㐨⮬㌟ࡢႠຊ࡟ࡼࡾ㸪Ἑ㐨 ࡀᏳᐃࡍࡿ㐣⛬࡛㉳ࡇࡿᕝᖜ⦰ᑠࢆ཯ᫎࡋ࡚࠸ࡿࡶࡢ࡜

ᛮࢃࢀࡿ㸬୍᪉㸪Ἑᗋᮦᩱ⢏ᚄ࡟ࡘ࠸࡚ࡣ㸪㛫ఆᮦỈไ ᑟධ༊࡟࠾࠸࡚㸪ᑟධᚋ࡟ ੈ௨ୗࡢ⢏ᚄࡢᅵ◁ࡀ☜ㄆ ࡉࢀࡿࡼ࠺࡟࡞ࡗࡓ㸬ࡇࢀࡣ᪂ࡓ࡟๰ฟࡉࢀࡓࡼ࡝ࡳ⎔

ቃࢆ཯ᫎࡋ࡚࠸ࡿࡶࡢ࡜ᛮࢃࢀࡿ㸬

Dᑐ↷༊ E㛫ఆᮦỈไᑟධ༊

ᅗ ࣁࣅࢱࢵࢺ࣐ࢵࣉ㸦༊ศㄪᰝ⤖ᯝ㸧

⾲ ᮏㄽ࡛ᐃ⩏ࡍࡿࣁࣅࢱࢵࢺ༊ศ

ྡ⛠ ≉ᚩ

᪩℩ ὶ㏿䛜㏿䛟䚸ⓑ䛟Ἴ❧䛳䛶䛔䜛㏿䛔ὶ䜜

ᖹ℩ Ἴ❧䛳䛶䛔䜛ὶ㏿䛜㏿䛔ὶ䜜䠄ⓑ䛟Ἴ❧䛳䛶䛔䛺䛔䠅 ῡ ࿘ᅖ䛾䝝䝡䝍䝑䝖䛻ẚ䜉䛶᫂䜙䛛䛻Ỉ῝䛜῝䛟䛺䛳䛶䛔䜛ሙᡤ

䠄㻌℩䛾ୗὶ䜔Ỉ⾪㒊䛻ከ䛔䠅

䛸䜝 Ἴ❧䛳䛶䛔䛺䛔༢ㄪ䛺ὶ䜜

䜘䛹䜏䜋䛸䜣䛹ὶ㏿䛜䛺䛟䚸ṆỈ䛻㏆䛔ὶ䜜

(5)

᫓ ኟ ⛅ ᫓ ኟ ⛅ ᫓ ኟ ⛅ ᫓ ኟ ⛅

䝙䝩䞁䜴䝘䜼㻭㼚㼓㼡㼕㼘㼘㼍㻌㼖㼍㼜㼛㼚㼕㼏㼍㻝

䝁䜲㻯㼥㼜㼞㼕㼚㼡㼟㻌㼏㼍㼞㼜㼕㼛㻌㻝㻝㻞㻞

䜼䞁䝤䝘㻯㼍㼞㼍㼟㼟㼕㼡㼟㻌㼍㼡㼞㼍㼠㼡㼟㻌㼘㼍㼚㼓㼟㼐㼛㼞㼒㼕㼕㻞㻝㻠㻞㻜㻟㻞㻟㻠㻞㻜㻢

䜸䜸䜻䞁䝤䝘㻯㼍㼞㼍㼟㼟㼕㼡㼟㻌㼍㼡㼞㼍㼠㼡㼟㻌㼎㼡㼑㼞㼓㼑㼞㼕

䜸䜲䜹䝽㼆㼍㼏㼏㼛㻌㼜㼘㼍㼠㼥㼜㼡㼟㻌㻝㻞㻞㻝㻝㻜㻞㻥㻞㻡㻣㻤㻡㻢㻢㻟㻡㻤㻝㻞㻣㻤

䜹䝽䝮䝒㼆㼍㼏㼏㼛㻌㼠㼑㼙㼙㼕㼚㼏㼗㼕㻌㻣㻝㻜

䝍䜹䝝䝲㻼㼔㼛㼤㼕㼚㼡㼟㻌㼛㼤㼥㼏㼑㼜㼔㼍㼘㼡㼟㻝㻠㻡㻝㻠㻞㻟㻝㻜

䜹䝬䝒䜹㻼㼟㼑㼡㼐㼛㼓㼛㼎㼕㼛㻌㼑㼟㼛㼏㼕㼚㼡㼟㻟㻟㻞㻟㻡㻝㻣㻞㻞㻡㻢㻝㻠㻤㻝㻝

䝗䝆䝵䜴㻹㼕㼟㼓㼡㼞㼚㼡㼟㻌㼍㼚㼓㼡㼕㼘㼘㼕㼏㼍㼡㼐㼍㼠㼡㼟㻌㻝

䝲䝬䝖䝅䝬䝗䝆䝵䜴㻯㼛㼎㼕㼠㼕㼟㻌㼙㼍㼠㼟㼡㼎㼍㼞㼍㼑㻌㻞㻥㻞㻞㻝㻡㻝㻡㻝㻠㻝㻡㻝㻞㻥

䝗䞁䝁㻻㼐㼛㼚㼠㼛㼎㼡㼠㼕㼟㻌㼛㼎㼟㼏㼡㼞㼍㻟㻞㻢㻞㻜㻝㻝㻟㻝㻝㻝㻡㻞㻝㻝㻞㻝

䝂䜽䝷䜽䝝䝊㻾㼔㼕㼚㼛㼓㼛㼎㼕㼡㼟㻌㼓㼕㼡㼞㼕㼚㼡㼟㻌㻝

䝅䝬䝶䝅䝜䝪䝸㻾㼔㼕㼚㼛㼓㼛㼎㼕㼡㼟㻌㼟㼜㻚㻯㻮㻌㻝㻝㻜㻝㻞㻞㻡㻝㻝

䝖䜴䝶䝅䝜䝪䝸㻾㼔㼕㼚㼛㼓㼛㼎㼕㼡㼟㻌㼟㼜㻚㻻㻾㻌㻝

䝇䝭䜴䜻䝂䝸㻳㼥㼙㼚㼛㼓㼛㼎㼕㼡㼟㻌㼜㼑㼠㼟㼏㼔㼕㼘㼕㼑㼚㼟㼕㼟㻌㻞㻝㻣㻝㻢㻝㻝㻤㻞㻢㻡

䜴䜻䝂䝸㻳㼥㼙㼚㼛㼓㼛㼎㼕㼡㼟㻌㼡㼞㼛㼠㼍㼑㼚㼕㼍㻌䝯䝎䜹㻻㼞㼥㼦㼕㼍㼟㻌㼘㼍㼠㼕㼜㼑㼟䝰䝒䝂㻼㼟㼑㼡㼐㼛㼞㼍㼟㼎㼛㼞㼍㻌㼜㼍㼞㼢㼍

㻡㻡㻠㻣㻤㻥㻠㻤㻠㻥㻥㻥

㻞㻝㻣㻝㻞㻡㻡㻝㻢㻥㻟㻟㻝㻣㻡㻣㻡㻤㻥㻝㻠㻠㻝㻣㻤㻠㻣㻞

ྜィ᥇ᤕಶయᩘ

ྜィฟ⌧✀ᩘ

㻞㻜㻝㻝

࿴ྡ Ꮫྡ

ᑐ↷༊ 㛫ఆᮦᑟධ༊

㻞㻜㻝㻝㻞㻜㻝㻞㻞㻜㻝㻞

ᅗ ᖹᆒฟ⌧✀ᩘ ᅗ ᖹᆒ᥇ᤕಶయᩘ

ᅗ ὶ㏿Ỉ῝ࣉࣟࢵࢺ

0.01 0.1 1 10 100 1000

0 200 400 600 800 1000

⢏ᚄ(䟚)

ᕝᖜ(䟛)

2011 2012

0.01 0.1 1 10 100 1000

0 200 400 600 800 1000

⢏ᚄ(䟚)

ᕝᖜ(䟛)

2011 2012

ᅗ Ỉ㠃ᖜἙᗋᮦᩱ⢏ᚄࣉࣟࢵࢺ

Dᑐ↷༊ E㛫ఆᮦỈไᑟධ༊ Dᑐ↷༊ E㛫ఆᮦỈไᑟධ༊

Dᑐ↷༊ E㛫ఆᮦỈไᑟධ༊

p=0.009<0.01 p=0.006<0.01 p=0.22 p=0.73

(6)

ᅗ ᖹᆒฟ⌧✀ᩘẚ㍑

ᅗ ࣐ࣖࢺࢩ࣐ࢻࢪࣙ࢘య㛗ࣄࢫࢺࢢ࣒ࣛ

㸦3㸧⪃ᐹ

D㛫ఆᮦỈไࡢຠᯝ

㛫ఆᮦỈไࡢᑟධ࡟ࡼࡗ࡚㸪ᬒほࣞ࣋ࣝࡢࣁࣅࢱࢵࢺ

ࡸ≀⌮⎔ቃ࡟ࡘ࠸࡚ࡣ㸪ከᵝ࡟࡞ࡿࡇ࡜ࡀㄪᰝ⤖ᯝࡼࡾ

☜ㄆࡉࢀࡓ㸬୍᪉㸪㨶㢮ࡢ⏕ᜥ⎔ቃ࡜ࡋ࡚ࡣ㸪ᑟධᚋ࡟

㛫ఆᮦỈไᑟධ༊ࡔࡅ࡛࡞ࡃ㸪ᑐ↷༊࡟࠾࠸࡚ࡶฟ⌧✀

ᩘࡀቑຍࡋ࡚࠸ࡿࡢ࡛㸪✀ᩘቑຍࡀ㛫ఆᮦỈไࡢᙳ㡪࠿

࡝࠺࠿ࢆᅗࡔࡅ࡛ࡣุ᩿࡛ࡁ࡞࠸㸬ࡑࡇ࡛㸪ᅗ࡟ ᑐ↷༊࡜㛫ఆᮦỈไᑟධ༊࡟࠾ࡅࡿฟ⌧✀ᩘࡢẚ㍑ࢆ

ᖺ࡜ ᖺ࡟ࡑࢀࡒࢀ⾜ࡗࡓ⤖ᯝࢆ♧ࡍ㸬 ᖺ

࡟ࡣ㸪ᑐ↷༊࡜㛫ఆᮦᑟධ༊࡜࡛ฟ⌧✀ᩘ࡟᭷ពᕪࡣ☜

ㄆࡉࢀ࡞࠸ࡀ㸪 ᖺ࡟ࡣ᭷ពᕪࡀ☜ㄆࡉࢀࡓ㸦S 7WHVW㸧㸬 ᖺ࡟ࡣྠ⛬ᗘࡢ㨶✀ᩘࡀฟ⌧ࡋ࡚࠸ࡓ ᆅⅬ࡟࠾࠸࡚㸪 ᖺ࡟ࡣ㛫ఆᮦỈไᑟධ༊࡟࠾࠸࡚᭷

ព࡟ฟ⌧✀ᩘࡀከ࠸࡜࠸࠺⤖ᯝࡀᚓࡽࢀࡓࡇ࡜࠿ࡽ㸪ࡇ

ࢀࡣ㸪㛫ఆᮦỈไᑟධࡢຠᯝࡀᑟධࡋࡓ༊㛫࡟࠾࠸࡚Ⓨ

⌧ࡉࢀࡓྍ⬟ᛶࢆ♧ࡋ࡚࠸ࡿ㸬ࡉࡽ࡟㸪ᕼᑡ✀࡛࠶ࡿࣖ

࣐ࢺࢩ࣐ࢻࢪࣙ࢘ࡢฟ⌧ಶయᩘ࡟╔┠ࡍࡿ࡜㸪㛫ఆᮦỈ ไᑟධ༊ࡢࡳ࡛ ᖺ࠿ࡽ ᖺ࡟࠿ࡅ࡚ቑຍࡋ࡚࠸

ࡿࡇ࡜ࡀࢃ࠿ࡿ㸦ᅗ㸧㸬࡞࠾㸪ᑐ↷༊࡟࠾ࡅࡿฟ⌧✀

ᩘࡢቑຍࡣ㸪 ᖺ࡟Ἑ㐨ࡑࡢࡶࡢ࡟ᑐࡋ࡚⾜ࢃࢀࡓከ

⮬↛ᕝ࡙ࡃࡾᨵಟࡢᙳ㡪ࢆ཯ᫎࡋ࡚࠸ࡿࡶࡢ࡜ᛮࢃࢀࡿ㸬 ࡍ࡞ࢃࡕୖす㒓ᕝࡢ⎔ቃ⮬యࡀ㸪 ᖺ⌧ᅾᅇ᚟㏵ୖ࡛

࠶ࡿࡇ࡜ࢆ♧ࡋ࡚࠸ࡿ㸬

E㛫ఆᮦỈไᑟධࡢ࣓ࣜࢵࢺ࡜ྍ⬟ᛶ

ᮏ◊✲ࡢᡂᯝࡣ㸪ᕝᖜࢆ☜ಖ࡛ࡁ࡞࠸ࡇ࡜࡛Ἑ㐨ෆࡢ

⎔ቃࡀ༢ㄪ໬ࡍࡿ࡜࠸࠺᪥ᮏࡢ㒔ᕷἙᕝࡀඹ㏻ࡋ࡚ᢪ࠼

࡚࠸ࡿၥ㢟ࢆゎỴࡍࡿࡇ࡜ࡀᮇᚅࡉࢀࡿ㸬ࡉࡽ࡟㛫ఆᮦ

Ỉไࡣ㸪ேຊ࡛Ᏻ౯࠿ࡘ⡆౽࡟᪋ᕤࡀྍ⬟࡞ᡭἲ࡛࠶ࡿ㸬 ࡑࡢࡓࡵ㸪ᗈࡃ඲ᅜࡢ㒔ᕷἙᕝࡢ⎔ቃ෌⏕࡬㐺⏝ࡀᮇᚅ

ࡉࢀࡿ㸬ࡉࡽ࡟㸪㛫ఆᮦỈไࡣ㸪ඖ᮶⏘ᴗᗫᲠ≀࡜ࡋ࡚

ྲྀࡾᢅࢃࢀࡿࡇ࡜ࡀከ࠿ࡗࡓ㛫ఆᮦࡸᕤ஦Ⓨ⏕▼ᮦࢆ㸪 Ἑᕝ⟶⌮࡟᭷ຠά⏝ࡍࡿᡭἲ࡛࠶ࡿࡇ࡜࠿ࡽ㸪Ἑᕝ⎔ቃ ࡢ෌⏕ᡭἲ࡜ࡋ࡚ࡢࡳ࡞ࡽࡎ㸪೺඲࡞ὶᇦ⟶⌮ࡸබඹ஦

ᴗ࡟࠾ࡅࡿࣜࢧ࢖ࢡࣝ࡬ࡶ኱ࡁ࡞ᐤ୚ࡀᮇᚅࡉࢀࡿ㸬

㸳㸬⤖ㄽ

ᮏㄽ࡛ࡣ㸪㛫ఆᮦ➼ࡢᆅሙᮦࢆά⏝ࡋࡓἙ㐨ෆ⮬↛෌

⏕ᕤἲࢆ㛤Ⓨ࣭ᑟධࡋ㸪ࡑࡢຠᯝ࡟ࡘ࠸࡚ホ౯ࢆ⾜ࡗࡓ㸬 ᚓࡽࢀࡓ⤖ᯝࢆ௨ୗ࡟♧ࡍ㸬

࣭ᅜෆእࡢඛ㥑ⓗ஦౛ࢆཧ⪃࡟㸪㛫ఆᮦ࠾ࡼࡧ⮬↛▼ࢆ

ά⏝ࡋࡓ㸪ேຊ࡛᪋ᕤྍ⬟࡞Ἑ㐨ෆ⮬↛෌⏕ᕤἲ㸦㸻㛫ఆᮦỈไ㸧ࢆ㛤Ⓨࡋࡓ㸬

࣭㛫ఆᮦỈไࡣ㸪ᑟධࡍࡿࡇ࡜࡛࿘㎶ࡢỈࡢὶࢀࢆከᵝ

࡟ࡋ㸪ࡑࡢ⤖ᯝᅵ◁ࡢศ⣭ࡸከᵝ࡞ࣁࣅࢱࢵࢺࢆ๰ฟ ࡍࡿࡇ࡜ࡀ☜ㄆࡉࢀࡓ㸬

࣭㛫ఆᮦỈไᑟධ࡟ࡼࡾ㸪ㄪᰝ༊ࡢฟ⌧㨶✀ᩘࡣ᭷ព࡟

ቑຍࡋࡓ㸬ࡑࡢࡓࡵ㸪㨶㢮ࡢ⏕ᜥ⎔ቃ෌⏕ࡢᡭἲ࡜ࡋ

୍࡚ᐃࡢຠᯝࢆ᭷ࡍࡿࡇ࡜ࡀ᫂ࡽ࠿࡜࡞ࡗࡓ

࣭㛫ఆᮦỈไࡣ㸪ேຊ࡛Ᏻ౯࠿ࡘ⡆౽࡟᪋ᕤࡀྍ⬟࡞ᡭ ἲ࡛࠶ࡿ㸬

࣭㛫ఆᮦỈไࡣ㸪ඖ᮶⏘ᴗᗫᲠ≀࡜ࡋ࡚ྲྀࡾᢅࢃࢀࡿࡇ

࡜ࡀከ࠿ࡗࡓᮦᩱࢆ᭷ຠά⏝ࡍࡿᡭἲ࡛࠶ࡿࡇ࡜࠿ࡽ㸪 Ἑᕝ⎔ቃࡢ෌⏕ᡭἲ࡜ࡋ࡚ࡢࡳ࡞ࡽࡎ㸪೺඲࡞ὶᇦ⟶

⌮ࡸබඹ஦ᴗ࡟࠾ࡅࡿࣜࢧ࢖ࢡࣝ࡬ࡶ኱ࡁ࡞ᐤ୚ࡀᮇ ᚅࡉࢀࡿ㸬

ཧ⪃ᩥ⊩

1) ከ⮬↛ᕝ࡙ࡃࡾ◊✲఍ⴭ㸸ከ⮬↛ᕝ࡙ࡃࡾ࣏࢖ࣥࢺࣈࢵࢡϪ

୰ᑠἙᕝ࡟㛵ࡍࡿἙ㐨ィ⏬ࡢᢏ⾡ᇶ‽㸹ゎㄝ, බ┈♫ᅋἲே᪥

ᮏἙᕝ༠఍, 2011

2) Whiteway S.L., Biron P.M., Zimmermann A., Venter O., Grant J.W.A., Do in-stream restoration structures enhance salmonid abundance? A meta-analysis, Canadian Journal of Fisheries and Aquatic Sciences, Vol. 67, Issue 5, pp.831-841, 2010

3) Kail J., Hering D., Muhar S., Gerhard M., Preis S., The use of large wood in stream restoration: Experiences from 50 projects in Germany and Austria, Journal of Applied Ecology, Vol. 44, Issue 6, pp.1145-1155, 2007

4) Dave Rosgen: Applied river morphology, Wildland Hydrogy, 1996 5) 㸦⊂㸧ᅵᮌ◊✲ᡤ ⮬↛ඹ⏕◊✲ࢭࣥࢱ࣮HP,

http://www.pwri.go.jp/team/kyousei/jpn/research/m3_04_48.htm 6) ཎ⏣Ᏺၨ㸪㧗ᒸᗈᶞ㸪኱▼ဴஓ㸪ⴛሙ♸୍㸸᪂ࡋ࠸Ἑ㐨Ᏻᐃ

ᕤἲࡢᐇ⏝໬࡟ྥࡅࡓㄪᰝ◊✲ࡢྲྀࡾ⤌ࡳ㸪Ἑᕝᢏ⾡ㄽᩥ㞟, Vol.19, pp.87-92, 2013.

7) Ỉ㎶ࡢࣇ࢕࣮ࣝࢻ࣑࣮ࣗࢪ࢔࣒◊✲఍HP, http://ameblo.jp/mizubefmk/

8) ὾㔝㱟ኵ㸪ఀ⸨ಙ⾜㸪ᒣᮏ୍ኵ⦅㸸Ỉ㎶ࡢᑠࢃࡊ㸪ᒣཱྀ┴ᅵ ᮌᘓ⠏㒊Ἑᕝㄢ㸪2007

9) ⚟␃ಟᩥ, Ἑᕝ࡟ά࠿ࡍ▼⤌ࡳᢏἲ, FRONT, 㸦㈈㸧ࣜࣂ࣮ࣇ

ࣟࣥࢺᩚഛࢭࣥࢱ࣮, ➨19ᕳ, 5ྕ, pp.14-17

㻌㸦 ཷ௜㸧

D㸦ᑟධ๓㸧 E㸦ᑟධᚋ㸧

p=0.39 p=0.03<0.05