᩼ཎܭ൲௨เẦỤỉᆷእὉἼὅỉඕ߷්Јᴾ ἩἿἍἋỉᚐௌᴾ

࠯঺ ᵐᵐᵖ ࠰ࡇᴾ Ҧٟᛯ૨ ᴾ

᩼ཎܭ൲௨เẦỤỉᆷእὉἼὅỉඕ߷්Јᴾ ἩἿἍἋỉᚐௌᴾ

ᴾ

ὼ᭗ᚐ΂ࡇỉ්؏ ᵥᵧᵱ ऴإểᴾ

ٶ଺஖ὉٶעໜỉܱยἙὊἑử෇ဇẲềὼᴾᴾ

‒

ɤිᴾ Ⴧԍᴾ

‒

ᵐᵎᵏᵕ

➨

➨ 1 ❶

... 1

1-1. ◊ ✲ 䛾⫼ ᬒ ཬ 䜃┠ ⓗ ... 1

1-1-1. 㠀 ≉ ᐃ ở ᰁ ※ 䛾䛄㠀 ᆒ ㉁ ᛶ 䛅䛸䛿 ... 3

1-1-2. 㠀 ≉ ᐃ ở ᰁ ※ 䛾䛄㠀 ᐃ ᖖ ᛶ 䛅䛸䛿 ... 5

1-1-3. ᮏ ◊ ✲ 䛾┠ ⓗ ... 7

1-2. ㄽ ᩥ 䛾ᵓ ᡂ ... 8

1-3. ␎ ㄒ ୍ ぴ ... 10

➨ 2 ❶

... 11

2-1. GIS 䜢⏝ 䛔䛯ὶ ᇦ ⟶ ⌮ : ཎ ༢ ఩ ἲ 䜢⏝ 䛔䛶⟬ ᐃ 䛧䛯᤼ ฟ ㈇ Ⲵ 㔞 䛾ホ ౯ ... 14

2-1-1. 䛿䛨䜑䛻 ... 14

2-1-2. ᪉ ἲ ... 15

2-1-3. ⤖ ᯝ 䛸⪃ ᐹ ... 18

2-1-4. 䜎䛸䜑 ... 26

2-2. QuickBird⏬ ീ 䛻䜘䜛ᑠ ὶ ᇦ 䝧䞊䝇䛾ᅵ ᆅ ฼ ⏝ ศ 㢮 䛸 Stepwiseἲ 䜢⏝ 䛔䛯Ἑ ᕝ ὶ ฟ ㈇ Ⲵ 㔞 䛾⟬ ᐃ ... 28

2-2-1. 䛿䛨䜑䛻 ... 28

2-2-2. ㄪ ᰝ ཬ 䜃ゎ ᯒ ᪉ ἲ ... 29

2-2-3. Ἑ ᕝ ὶ 㔞 ཬ 䜃Ỉ ㉁ ศ ᯒ ⤖ ᯝ ... 36

2-2-4. ⪃ ᐹ ... 39

2-2-5. 䜎䛸䜑 ... 44

2-3. 㠀 ≉ ᐃ ở ᰁ ※ 䛛䜙䛾㈇ Ⲵ ᥎ ᐃ ᡭ ἲ 䛾ᥦ ᱌ ... 46

➨ 3 ❶

... 48

3-1. ῱ ὶ Ỉ ୰ 䛻䛚䛡䜛◪ 㓟 䜲䜸䞁⃰ ᗘ 䛸ᆅ ᙧ ཬ 䜃㔪 ⴥ ᶞ ᯘ 㠃 ✚ 䛾ᙳ 㡪 ... 50

3-1-1. 䛿䛨䜑䛻 ... 50

3-1-2. ᪉ ἲ ... 52

3-1-3. ⤖ ᯝ ... 55

3-1-4. ⪃ ᐹ ... 58

3-1-5. 䜎䛸䜑 ... 62

3-2. ὶὶ ᇦ ≉ ᛶ 䠄㯮 䝪䜽䞉㠀 㯮 䝪䜽䞉ᅵ ᆅ ฼ ⏝ 䠅䛜ᨭ 㓄 䛩䜛 P,N 䛾Ἑ ᕝ ὶ ฟ 䝥䝻䝉䝇 ... 63

3-2-1. 䛿䛨䜑䛻 ... 63

3-2-2. ᪉ ἲ ... 66

3-2-3. ⤖ ᯝ ... 69

3-2-4. ⪃ ᐹ ... 75

3-2-5. 䜎䛸䜑 ... 80

3-3. ᾐ ㏱ 䞉ὶ ฟ 䝥䝻䝉䝇䛻䛚䛔䛶๪ ḟ ⓗ 䛻Ỉ ㉁ 䜢ኚ 䛘䜛⎔ ቃ ᅉ Ꮚ 䜢ゎ ᯒ 䛩䜛䛻䛿 ... 81

➨ 4 ❶

... 83

4-1. 10ᖺ 㛫 䛾᭶ ౛ Ỉ ㉁ ㄪ ᰝ 䛻䜘䜛ᰤ 㣴 ሷ ὶ ฟ ≉ ᛶ 䛾▷ ᮇ ኚ ື せ ᅉ 䛾ゎ ᯒ ... 84

4-1-1. 䛿䛨䜑䛻 ... 84

4-1-2. ᪉ ἲ ... 85

4-1-3. ⤖ ᯝ ཬ 䜃⪃ ᐹ ... 92

4-1-4. 䜎䛸䜑 ... 99

4-2. ฟ Ỉ ᫬ 䛻䛚䛡䜛Ἑ ᕝ ὶ ฟ 䝥䝻䝉䝇䛾ኚ ໬ ... 100

➨ 5 ❶

... 102

5-1. Ἑ ᕝ Ỉ ㉁ 䛾ᙧ ᡂ 䝥䝻䝉䝇◊ ✲ 䛸䛧䛶䛾㈉ ⊩ ... 102

5-2. ௒ ᚋ 䛾ὶ ᇦ ⎔ ቃ 䝬䝛䞊䝆䝯䞁䝖䜈䛾ᥦ ゝ ... 104

ཧ ⪃ ᩥ ⊩... 106

᦬ 㻌 せ ... 115

Abstract ... 118

ㅰ 㻌 ㎡ ... 122

Ꮫ ఩ ㄽ ᩥ 䛾ᇶ ♏ 䛸䛺䜛Ꮫ ఍ ㄅ බ ⾲ ㄽ ᩥ 䛾䝸䝇䝖 ... 124

1

➨

➨ 1❶ ㅖ ㄽ

1-1. ◊ ✲ 䛾⫼ ᬒ ཬ 䜃┠ ⓗ

㏆ ᖺ 䠈 ே 㛫 ά ື 䛾 ቑ ኱ 䛿 Ỉ ῝ 䛾 ὸ 䛔 † ἟ 䜔 䠈 ὶ 䜜 䛾 ᙅ 䛔 Ἑ ᕝ 䜔 ‴ ➼ 䛾 㛢 㙐 ᛶ Ỉ ᇦ 䛻䛚䛔 䛶⏕ ά ᤼ Ỉ 䞉ᕤ ሙ ᗫ Ỉ 䞉㎰ ᆅ 䜈䛾 ᪋ ୚ 䛥䜜䛯ྛ ✀ ⫧ ᩱ ➼ 䛾 ὶ ฟ 䛻䜘䜚ᐩ

ᰤ 㣴 ໬ 䜢ᘬ 䛝 ㉳ 䛣䛧䛶䛔 䜛 䚹ᐩ ᰤ 㣴 ໬ 䛿❅ ⣲ 䞉䝸 䞁 䠄N,P䠅䛾ᰤ 㣴 ሷ 㢮 䛜 㐣 ๫ 䛻Ỉ ୰ 䛻

ྵ 䜎 䜜 䛶䛔 䜛 ≧ ែ 䛷 䛒 䜚 䠈 ග ྜ ᡂ 䛻 䜘 䜛 ⸴ 㢮 䛾 ኱ ⦾ Ṫ 䜢 ᣍ 䛝 䠈 ㉥ ₻ 䜔 䜰 䜸 䝁 䛾 ཎ ᅉ 䛸 䛺䜛 䚹 䛣䜜 䜙 ኱ 㔞 䛾 ⸴ 㢮 䛿ኪ 㛫 䛻 㓟 ⣲ 䜢 ᾘ ㈝ 䛩 䜛 䛰 䛡䛷 䛺䛟 䠈Ṛ ⁛ 䛧 䛶 Ỉ ᗏ 䛻 ỿ Ẋ 䛧 ศ ゎ 䛥䜜 䜛㝿 䛻䜒 㓟 ⣲ 䜢ᾘ ㈝ 䛩 䜛䛯 䜑 䠈Ỉ ୰ 䛾⁐ Ꮡ 㓟 ⣲ 㔞 䛜 Ḟ ஈ 䛧䛶㟷 ₻ ➼ 䠈㨶 ௓ 㢮 䜈 䜒 ῝ ้ 䛺 ᙳ 㡪 䜢 ୚ 䛘 䜛 䚹 Ỉ 㐨 Ỉ ※ 䛾 † ἟ ➼ 䛻 䛚 䛔 䛶 ᐩ ᰤ 㣴 ໬ 䛜 㐍 ⾜ 䛧 䛯 ሙ ྜ 䛻 䛿䠈⸴ 㢮 䛜 ␗ ᖖ ቑ Ṫ 䛩 䜛 ஦ 䛷 䠈␗ ⮯ ࿡ 㞀 ᐖ 䞉จ 㞟 ỿ Ẋ ฎ ⌮ 㞀 ᐖ 䞉䜝㐣 㛢 ሰ 䞉 ₃ ฟ 㞀 ᐖ ➼ 䛾 ၥ 㢟 䛜 Ⓨ ⏕ 䛧 䠈⤒ ῭ ⓗ 䛺ᦆ ኻ 䛻 䛴 䛺 䛜 䜛 ஦ 䜒 䛒 䜛 䚹䛣䛾 䜘䛖䛻 䠈⮬ ↛ ⎔ ቃ ⓗ 䛻䜒 ♫ ఍ ⤒ ῭ ⓗ 䛻䜒 ㈇ 䛾 ᙳ 㡪 䜢ཬ 䜌䛩 ே Ⅽ ⓗ 䛺ᐩ ᰤ 㣴 ໬ 䜢ᢚ ไ 䛩䜛 Ⅽ 䛾 ᑐ ⟇ 䛿㔜 せ 䛷䛒䜛䚹

ὶ ᇦ 䛻䛚䛡䜛 N,P 䛾䝋䞊䝇䛿䠈ே Ⅽ ⏤ ᮶ 䛾Ⓨ ⏕ ※ ➼ 䛷⏕ ά ᤼ Ỉ 䜔ᕤ ሙ 䞉␆ ⏘ ᗫ Ỉ 䛾䜘䛖䛻Ⅼ 䛸 䛧䛶ᢕ ᥱ 䛷䛝䜛≉ ᐃ ở ᰁ ※ 䛸࿧ 䜀䜜䜛䜒䛾䛸 䠈㎰ ᆅ 䜔᳃ ᯘ ➼ 䛾䜘䛖䛻㠃 䛸䛧䛶ᢅ 䜟䜜䜛㠀 ≉ ᐃ ở ᰁ ※ 䛻኱ ู 䛥䜜䜛 ^{1 )}䚹≉ ᐃ ở ᰁ ※ 䛿୺ 䛻䜅䜝Ỉ 䜔ྎ ᡤ ᤼ Ỉ 䛸䛔䛳䛯ᒓ ே ⓗ 䛺䠄䛒䜛䛔䛿ᐙ ␆ 1 㢌 ᙜ 䛯䜚䛾⣅ ᒀ 䜔ᕤ ሙ ᪋ タ ᙜ 䛯䜚䛾᤼ Ỉ ➼ 䛾䠅㡯

┠ 䛷䠈༢ ఩ 1ே 䠄1 㢌 䛒 䜛䛔䛿1 ᪋ タ 䠅ᙜ 䛯䜚䛾᤼ ฟ 㔞 䛸䛧䛶✚ ⟬ 䛥䜜䜛䚹 ≉ ᐃ ở ᰁ ※ 䛛䜙䛾 ㈇ Ⲵ 䛿䠈 Ⓨ ⏕ 䛧䛯 㔞 䛜 ᤼ Ỉ ⁁ 䜔 ഃ ⁁ 䜢㏻ 䛧䛶 ᦆ ኻ 䛜 ᑡ 䛺䛟 ┤ ᥋ Ỉ ⣔ 䛻 ᤼ ฟ 䛥 䜜 䜛 ஦ 䛛 䜙 䠈 Ⓨ ⏕ 㔞 䍦 ᤼ ฟ 㔞 䛸 ⪃ 䛘 䜙 䜜 䠈 Ⓨ ⏕ ㈇ Ⲵ 䛸 ࿧ 䜀 䜜 䛶 䛔 䜛 䚹 䛣 䜜 䛻 ᑐ 䛧 䛶 㠀

≉ ᐃ ở ᰁ ※ 䛿 䠈㎰ ᆅ 䜈 䛾 ᪋ ⫧ 㔞 䜔 ᯘ ᆅ 䜔 ᕷ ⾤ ᆅ 䜈 䛾 ኱ Ẽ 㝆 ୗ ≀ ➼ 䛜 ※ 䛸 䛺䜚 䠈༢

఩ 㠃 ✚ ᙜ 䛯 䜚䛾 ᤼ ฟ 㔞 䛸 䛧 䛶 ✚ ⟬ 䛥䜜 䜛 䚹 㠀 ≉ ᐃ ở ᰁ ※ 䛛䜙䛾 ㈇ Ⲵ 䛿䠈 ὶ ฟ ⤒ ㊰ 䛜

⾲ 㠃 ὶ ฟ 䞉ᆅ ୗ ᾐ ㏱ 䞉 Ἑ ᕝ అ ὶ Ỉ 䞉 ᬯ Ὼ ᤼ Ỉ 䛾䜘䛖䛻ከ ᒱ 䛻䜟䛯䜛䛯 䜑 䠈Ⓨ ⏕ 䛧䛯㈇

Ⲵ 䛜 ᤼ ฟ 䛻 ⮳ 䜛 䜎 䛷 䛾 ኚ ໬ 䛜 ኱ 䛝 䛔 ஦ 䛛 䜙 䠈 Ⓨ ⏕ 㔞 䍴 ᤼ ฟ 㔞 䛸 ⪃ 䛘 䜙 䜜 䠈 ᤼ ฟ ㈇ Ⲵ

2 䛸࿧ 䜀䜜䜛䚹

༢ ⣧ 䛻 Ⓨ ⏕ 䞉᤼ ฟ 䛥䜜䜛Ỉ 㔞 䛰 䛡䛷䜒 ᤼ ฟ Ỉ 㔞 䜢ṇ ☜ 䛻 ᢕ ᥱ 䛩䜛 ஦ 䛿ᅔ 㞴 䛷䛒 䜛 䛜䠈㠀 ≉ ᐃ ở ᰁ ※ 䛛䜙䛾 N,P 䛾᤼ ฟ 㔞 䜢ṇ ☜ 䛻ᢕ ᥱ 䛩䜛 ஦ 䛿᭦ 䛻㞴 䛧䛔䚹౛ 䛘䜀㎰

ᆅ 䛷䛿䠈᪋ ⫧ 䛻䜘䜚N䛜౪ ⤥ 䛥䜜䜛䚹ᅵ ተ ୰ 䛾 N䛾䜋䛸䜣䛹䛿᭷ ᶵ ែ 䛷䛒䜚䠈䛣䛾୍ 㒊 䛜ᚤ ⏕ ≀ 䛻䜘䛳䛶ศ ゎ 䛥䜜䜰䞁䝰䝙䜴䝮䜲䜸䞁䠄NH4^䠇䠅䛸䛺䜛 ^{2 )}䚹㎰ ⪔ ᆅ ᅵ ተ 䛷䛿 NH4 䠇䛜䜰䞁䝰䝙䜰㓟 ໬ ⳦ 䛻䜘䛳䛶 䠈㏿ 䜔䛛䛻◪ 㓟 䜲䜸䞁䠄NO3-䠅䛻㓟 ໬ 䛥䜜䜛䚹୍ ᗘ NO3-

䛻䛺䜛䛸ᅵ ተ 䛾㝜 䜲䜸䞁 ಖ ᣢ ⬟ 䛿㠀 ᖖ 䛻ᑠ 䛥䛔 䛯䜑 䠈ᅵ ተ Ỉ 䛾⛣ ື 䛻 క 䛳䛶 NO3-䛿 ὶ ฟ 䛩 䜛 ^{3 )}䚹 䛧 䛛 䛧 䛺 䛜 䜙 䛭 䛖 䛧 䛯 ሙ ྜ 䛷 䜒 䠈 ᭷ ᶵ ≀ 䛜 ከ 㔞 䛻 Ꮡ ᅾ 䛩 䜛 ᎘ Ẽ ⓗ 䠄 㑏 ඖ

ⓗ 䠅᮲ ௳ ୗ 䛷䛿⬺ ❅ 䛻䜘䜚NO₃^-䛾ὶ ฟ 䛿ᢚ ไ 䛥䜜䜛 ^{4 )}䚹◪ ໬ 䜔⬺ ❅ ά ᛶ 䛿ᅵ ተ 䛾‵

₶ ᮲ ௳ 䛻 䜘䛳 䛶ᨭ 㓄 䛥 䜜 䜛 䛯 䜑 䠈N 䛾 Ἑ ᕝ 䜈 䛾 ᤼ ฟ 䜢⪃ 䛘 䜛 ሙ ྜ 䛻 䛿 ᆅ ᙧ 䛾 ᙳ 㡪 䜒

⪃ ៖ 䛩䜛ᚲ せ 䛜䛒䜛^{5 )}䚹

䜎 䛯 䠈ᅵ ተ ୰ 䛾 䝸 䞁 㓟 䛿᭷ ᶵ ែ 䛸 ↓ ᶵ ែ 䛷 Ꮡ ᅾ 䛩 䜛 䛜 䠈᪋ ⫧ 䛜 ⾜ 䜟 䜜 䜛⪔ ᆅ ᅵ ተ 䛷 䛿 ↓ ᶵ ែ 䝸 䞁 㓟 䛜 ୺ せ 䛺 ᙧ ែ 䛸 䛺 䛳 䛶 䛔 䜛 䚹 ↓ ᶵ ែ 䝸 䞁 㓟 䛿 㓟 ᛶ 䡚 ୰ ᛶ ᅵ ተ 䛷 䛿 䜰䝹䝭䝙䜴䝮䜔㕲 䛻≉ ␗ ྾ ╔ 䛥䜜 䠈䜰䝹䜹䝸ᅵ ተ 䛷䛿㞴 ⁐ ᛶ 䛾 䜹䝹䝅䜴䝮 ሷ 䛸䛧䛶ᅵ ተ 䛻 ᅛ ᐃ 䛥 䜜 䜛 䚹 䛣 䛾 Ⅽ 䠈 ୍ ⯡ 䛻 ᅵ ተ ⁐ ᾮ ୰ 䛾 ↓ ᶵ ែ 䝸 䞁 㓟 ⃰ ᗘ 䛿 㠀 ᖖ 䛻 ప 䛟 䠈 ⁐ ⬺ 䛻䜘䛳䛶ኻ 䜟䜜䜛䝸䞁㓟 㔞 䜒ᑡ 䛺䛔䚹 ᚑ 䛳䛶䠈Ἑ ᕝ 䜈䛾୺ せ 䛺P᤼ ฟ 䝥䝻䝉䝇䛸䛧䛶䛿䠈 㝆 㞵 ᫬ 䛻䛚䛡䜛⾲ ᒙ ᅵ ተ 䛾ὶ ฟ 䛻క 䛖ᠱ ⃮ ែ 䛾 P 䛸⪃ 䛘䜙䜜䛶䛔䜛䚹

䛣䛾䜘䛖䛻」 㞧 䛺≀ ㉁ ᚠ ⎔ 䜢⤒ 䛶ὶ ฟ 䛩䜛㠀 ≉ ᐃ ở ᰁ ※ 䛛䜙䛾N,P䛷䛒䜛䛜䠈䛭䜜 䜙䛜 ὶ ᇦ ⎔ ቃ ಖ ඲ 䛾 ほ Ⅼ 䛛䜙ὀ ┠ 䛥䜜 䜛 䜘䛖䛻䛺䛳䛯 䛾 䛿ẚ ㍑ ⓗ ᭱ ㏆ 䛾 ஦ 䛷䛒 䜛 䚹 䛭 䛾 䛝 䛳䛛 䛡䛿 䠈 † ἟ ἲ ไ ᐃ 䛛䜙 20 ᖺ 䜢⤒ 㐣 䛧䛯 䛻 䜒 㛵 䜟 䜙 䛪 ⎔ ቃ ᇶ ‽ 䛾 㐩 ᡂ ⋡ 䛜 COD,TN,TP ඹ 䛻 50%⛬ ᗘ 䛸㢌 ᡴ 䛱䛷ᨵ ၿ 䛜ぢ 䜙䜜䛺䛛䛳䛯 ஦ 䛷䛒䜛䚹2005 ᖺ 1 ᭶ 䛾 䇾 䛂 † ἟ ⎔ ቃ ಖ ඲ ไ ᗘ 䛾 ᅾ 䜚 ᪉ 䛻 䛴 䛔 䛶 䛃 䛻 ಀ 䜛 ୰ ኸ ⎔ ቃ ᑂ ㆟ ఍ ⟅ ⏦ 䇿 䛷 䠈 㠀 ≉ ᐃ ở ᰁ ※ ᑐ ⟇ 䛾᥎ 㐍 䛜ᥦ ᱌ 䛥䜜䛯^{6 )}䚹ྠ ᖺ 6᭶ 䛻䛿† ἟ Ỉ ㉁ ಖ ඲ ≉ ู ᥐ ⨨ ἲ 䛜ᨵ ṇ 䛥䜜䠈㠀 ≉ ᐃ ở ᰁ ※ ㈇ Ⲵ ᑐ ⟇ 䛾᥎ 㐍 ➼ 䛜᫂ グ 䛥䜜䛯 ^{7 )}䚹2006 ᖺ 3 ᭶ 䛻䛿䠈ᅜ ᅵ

஺ ㏻ ┬ 䠈㎰ ᯘ Ỉ ⏘ ┬ 䠈 ᯘ 㔝 ᗇ 䠈⎔ ቃ ┬ 䛻䜘䜚䛂† ἟ Ỉ ㉁ 䛾䛯䜑䛾ὶ ᇦ ᑐ ⟇ 䛾ᇶ ᮏ ⓗ

⪃ 䛘 ᪉ 䛃 䛜 䜎 䛸 䜑 䜙 䜜 䠈 㠀 ≉ ᐃ ở ᰁ ※ ᑐ ⟇ ᐇ ᪋ 䛾 䛯 䜑 䛾 ᇶ ᮏ ⓗ 䛺 ⪃ 䛘 ᪉ 䛜 ♧ 䛥 䜜 䛯

3

8 )䚹䛣䜜䜢ཷ 䛡䛶 䠈2009ᖺ 3᭶ 䛻䛿† ἟ ➼ 䛾Ỉ ㉁ ಖ ඲ 䛾䛯䜑䛻㠀 ≉ ᐃ ở ᰁ ※ ᑐ ⟇ 䜢

඲ ᅜ ⓗ 䛻 ᥎ 㐍 䛩 䜛 ஦ 䜢 ┠ ⓗ 䛸 䛧䛶 䛂 㠀 ≉ ᐃ ở ᰁ ※ ᑐ ⟇ 䛾 ᥎ 㐍 䛻 ಀ 䜛 䜺䜲䝗 䝷䜲䞁 䠄 ➨ 1 ∧ 䠅^{9 )}䛃䛜ᩚ ഛ 䛥䜜䛯 䚹 䛣䜜䜎䛷† ἟ ⎔ ቃ ಖ ඲ ᑐ ⟇ 䛸 䛧䛶ᗈ ⠊ 䛺᪋ ⟇ 䜢ㅮ 䛨䛶䛝䛯⎔

ቃ ┬ 䛜 䠈䛭 䛾 ↔ Ⅼ 䜢 㠀 ≉ ᐃ ở ᰁ ※ 䛻 ⤠ 䜚䛣 䜣 䛰 ᑓ ⏝ 䛾 䜺䜲 䝗䝷 䜲䞁 䜢 స 䛳䛯 䛸 䛣䜝 䛻 䠈 㠀 ≉ ᐃ ở ᰁ ※ ᑐ ⟇ 䛾 ၥ 㢟 䛾኱ 䛝䛥䛸㞴 䛧䛥䛜⾲ 䜜䛶䛔䜛 䚹

ᅜ ෆ 䛾◊ ✲ ศ 㔝 䛻䛚䛔䛶䛿䠈1980 ᖺ 㡭 䛻࿴ ⏣ 䛜⾜ 䛳䛯㒔 ᕷ 㒊 䜢ᑐ ㇟ 䛸䛧䛯㠀 ≉ ᐃ ở ᰁ ※ 䛾◊ ✲ 䛜ඛ 㥑 䛡䛸 䛺䛳䛯 ^{1 0 )}䚹Ỉ ⎔ ቃ Ꮫ ఍ ㄅ 䛷䛿 1997 ᖺ 䛻䛂䝕䜱䝣䝳䞊䝈䝫 䝸䝳䞊䝅䝵䞁䛃^{11 , 1 2 )}䠈2003 ᖺ 䛻䛂ὶ ᇦ Ỉ ⎔ ቃ 䛃1 3 , 1 4 )䠈2007ᖺ 䛻䛂ᨵ ṇ † ἟ ἲ-䝜䞁䝫䜲䞁 䝖 ᑐ ⟇ 䛸 † ㎶ ⎔ ቃ ಖ ㆤ-䛃1 5 , 1 6 )䛸 ᐃ ᮇ ⓗ 䛻 ≉ 㞟 䜢⤌ 䜏 㠀 ≉ ᐃ ở ᰁ ※ 䛻 䛴 䛔 䛶 ᳨ ウ 䛥 䜜 䛶䛝 䛯 䚹ึ ᮇ 䛾 ◊ ✲ 䛿ಶ ู ᆅ ┠ 䜢ᑐ ㇟ 䛸 䛧 䛶᝟ ሗ 䜢 㞟 䜑 䜛 ஦ 䛻 ὀ ຊ 䛧䛶䛔 䛯 䜘 䛖䛰 䛜 䠈ከ 䛟 䛾 ◊ ✲ ⪅ 䛜 ⥅ ⥆ ⓗ 䛺ྲྀ 䜚⤌ 䜏 䜢⥆ 䛡 䜛 ୰ 䛷 ᅧ ᯇ 䜙 ^{1 6 )}䛻 䜘 䛳 䛶 䠈㠀 ≉ ᐃ ở ᰁ

※ 䛛䜙䛾 ㈇ Ⲵ 䜢 ㄝ ᫂ 䛩䜛 䛂 㠀 ᆒ ㉁ ᛶ 䛃䛸 䛂㠀 ᐃ ᖖ ᛶ 䛃 䛸䛔 䛖䜻 䞊䝽䞊 䝗䛜♧ 䛥䜜䛯 䚹2011 ᖺ 䛾ྂ ⡿ 䜙䛻䜘䛳䛶⾜ 䜟䜜䛯 ኱ つ ᶍ 䝥䝻䝆䜵䜽 䝖 䛂㠀 ≉ ᐃ ở ᰁ ※ 䛛䜙䛾 ὶ ฟ ㈇ Ⲵ 㔞 䛾 ᥎ ィ ᡭ ἲ 䛻㛵 䛩䜛◊ ✲ 䛃^{1 7 )}䛷䛿䠈㐣 ཤ 䛻⾜ 䜟䜜䛯㠀 ≉ ᐃ ở ᰁ ※ 䜢ᑐ ㇟ 䛸䛧䛯ᩥ ⊩ ᩚ

⌮ 䛻 䜒 䛸 䛵 䛟 ཎ ༢ ఩ 䝕 䞊 䝍 䝧 䞊 䝇 䛜 స ᡂ 䛥 䜜 䛯 䚹 䜎 䛯 䛣 䛾 ᫬ 䛻 䠈 㠀 ≉ ᐃ ở ᰁ ※ 䛛 䜙 䛾

㈇ Ⲵ 䛿䠈ྠ 䛨ᅵ ᆅ ฼ ⏝ 䛷䛒䛳䛶䜒ᆅ ᇦ 䜔฼ ⏝ 䛾䛥䜜᪉ 䛻䜘䛳䛶್ 䛜␗ 䛺䜛䛂㠀 ᆒ ㉁ ᛶ 䛃 䛸 䠈 㝆 㞵 䜔 Ⴀ ㎰ ᙧ ែ 䛾 ኚ ໬ 䛸 䛔 䛳 䛯 䛂 㠀 ᐃ ᖖ ᛶ 䛃 䛸 䛔 䛖 ≉ ᚩ 䜢 ᣢ 䛴 䠈 䛸 䛔 䛖 ᴫ ᛕ 䛸 䛧 䛶

ᩚ ⌮ 䛥䜜䛯䚹

1-1-1.

㠀 ≉ ᐃ ở ᰁ ※ 䛾 㠀 ᆒ ㉁ ᛶ 䛾ཎ ᅉ 䛸䛧䛶䛿 䠈ᅵ ተ 䞉᳜ ⏕ 䞉ᆅ ᙧ 䛒䜛䛔䛿⫧ ᇵ ⟶ ⌮ ➼ 䛾 ே Ⅽ ⓗ ᮲ ௳ 䛾 㐪 䛔 䛻 䜘 䛳 䛶 䠈 ྾ ╔ 䠈 ỿ 㝆 䠈 ሁ ✚ 䠈 ᾐ 㣗 䠈 ෌ ᠱ ⃮ 䠈 ⁐ ゎ 䞉 ศ ゎ ➼ 䛾 ከ ᵝ 䛺䝥䝻䝉䝇䛜 N,P 䛾ὶ ฟ 㔞 䛻ᙳ 㡪 䛩䜛䛸⪃ 䛘䜙䜜䜛 1 0 , 1 3 , 1 6 )䚹

ᅵ ተ 䛻 䜘䜛 Ỉ ㉁ 䜈 䛾 ᙳ 㡪 䛸 䛧 䛶 䠈ᯇ ୸ ^{1 8 )}䛿䝷 䜲䝅 䝯䞊 䝍䞊 䜢⏝ 䛔䛯 㯮 䝪 䜽 ᅵ 䛸 ◁ ㉁ ᅵ 䛾ẚ ㍑ 䛷䠈⫧ ᩱ ୰ 䛾 N 䛾ᾐ ㏱ ⁐ ⬺ ⋡ 䛿㯮 䝪䜽ᅵ 䛜 25䡚32%䠈◁ ㉁ ᅵ 䛜 58䡚66%

䛸䠈◁ ㉁ ᅵ 䛾᪉ 䛜2ಸ ⛬ ᗘ ኱ 䛝䛔䛸ሗ ࿌ 䛧䛶䛔 䜛 䚹ᒸ ᐊ 䜙^{1 9 )}䛿〓 Ⰽ ᳃ ᯘ ᅵ 䠈㯤 Ⰽ ᅵ 䠈

⅊ Ⰽ ప ᆅ ᅵ ཬ 䜃 ᒾ ᒌ ᅵ 䛛䜙䛾 㣴 ศ ື ែ ≉ ᛶ 䛻 䛴 䛔 䛶䝷䜲䝅䝯䞊 䝍䞊 䜢⏝ 䛔 䛶ㄪ ᰝ 䛧

4

䛯䚹ᾐ ㏱ Ỉ ୰ 䛾 NO3-⃰ ᗘ 䛿 䠈ᅵ ተ ୰ 䛾↓ ᶵ ែ ❅ ⣲ ྵ 㔞 䛜ከ 䛔ᅵ ተ 䜋䛹㧗 䛟䛺䜛ഴ

ྥ 䜢♧ 䛧䠈⅊ Ⰽ ప ᆅ ᅵ 䠈〓 Ⰽ ᳃ ᯘ ᅵ 䠈㯤 Ⰽ ᅵ 䠈ᒾ ᒌ ᅵ 䛾㡰 ␒ 䛷㧗 䛔 ⤖ ᯝ 䛰 䛳䛯䚹 ᅵ ተ 䛜 ᣢ 䛳 䛶䛔 䜛 ↓ ᶵ ❅ ⣲ 䛾 ౪ ⤥ 䠈䛒 䜛 䛔 䛿 㯮 䝪 䜽 ᅵ 䛾 䝸 䞁 㓟 ྾ ╔ ⬟ 䛻 ௦ ⾲ 䛥䜜 䜛 䜘 䛖 䛺྾ ╔ ಀ ᩘ 䛾㐪 䛔䛜 ᅵ ተ ᾐ ㏱ Ỉ 䛾Ỉ ㉁ 䛻ᙳ 㡪 䜢୚ 䛘䛶䛔䜛䛸⪃ 䛘䜙䜜䜛䚹

ᡃ 䛜 ᅜ 䛾 ᳃ ᯘ ᳜ ⏕ 䛻 䛚䛔 䛶 䠈ே ᕤ ᯘ 䛸 ⮬ ↛ ᯘ 䛾 㐪 䛔 䛜 ᭱ 䜒 ኱ 䛝 䛺 ༊ ศ 䛷 䛒 䜛 䚹 ᪥ ᮏ 䛾ே ᕤ ᯘ 䛿᳃ ᯘ 㠃 ✚ 䛾 40䠂䜢༨ 䜑䠈୺ 䛻䝇䜼䞉䝠䝜䜻䛜᳜ ᱂ 䛥䜜䛯㔪 ⴥ ᶞ ᯘ 䛸䛺䛳

䛶䛔䜛 ^{2 0 )}䚹᳜ ⏕ 䛻䜘䜛Ỉ ㉁ 䜈䛾ᙳ 㡪 䛸䛧䛶䠈Kristensen et al.^{2 1 )}䛻䜘䜛䛸䠈㔪 ⴥ ᶞ 䛷䛿

ⴠ ⴥ ᗈ ⴥ ᶞ 䛻ẚ 䜉 䛶 1.2䡚3.6 ಸ 䛾 N ㈇ Ⲵ 㔞 䛜 ほ   䛥䜜 䛶䛔 䜛 䚹䛣䛾 ⌮ ⏤ 䛸 䛧䛶 䠈 Watanabe et al.^{2 2 )}䛿㔪 ⴥ ᶞ 䛾ⴥ 㠃 ᙧ ≧ 䛜ከ 䛟䛾 ஝ ᛶ ỿ ╔ ≀ 䜢⿵ ㊊ 䛩 䜛䛸ሗ ࿌ 䛧䛶䛔 䜛 䚹 ஂ ⏣ 䜙 ^{2 3 )}䛻 䜘䜜 䜀 䠈 㔪 ⴥ ᶞ ᯘ 䛷 䛿 ⴥ 䛾 ⾲ 㠃 䛻 ௜ ╔ 䛧䛯 㞵 䛜 䛭 䛾 䜎 䜎 ⵨ Ⓨ 䛧 䛶 ኱ Ẽ ୰ 䜈ᖐ 䜛㐽 ᩿ ⵨ Ⓨ 㔞 䛜ከ 䛔஦ 䜒ᣦ ᦬ 䛥䜜䛶䛔䜛䚹䛭䛾௚ 䠈ᶞ ✀ 䛾㐪 䛔䛻䜘䜛 N ྾

཰ 㔞 䛾ᕪ 䜔ᯘ ᗋ ⎔ ቃ 䛾㐪 䛔䛻䜘䜛ᅵ ተ ୰ 䛾 N ື ែ 䛾ᕪ 䜒῱ ὶ Ỉ ㉁ 䛻ᙳ 㡪 䜢୚ 䛘䛶 䛔䜛䛸⪃ 䛘䜙䜜䜛䚹

⫧ ᇵ ⟶ ⌮ 䛺䛹䛾 ே Ⅽ ⓗ ᮲ ௳ 䛻䜘䜛 Ỉ ㉁ 䜈䛾 ᙳ 㡪 䛸 䛧䛶 䛿䠈௦ ᥙ 䛝 ᮇ 䛾Ỉ ⏣ 䛻䛚 䛡 䜛 㧗 ⃮ ᗘ Ỉ 䛾 ㉺ ὶ ➼ 䛾ᙳ 㡪 䜢ゎ ᯒ 䛧䛯 ◊ ✲ 䛜 ௦ ⾲ ⓗ 䛷 䛒 䜛 䚹 ㏆ ⸨ 䜙 ^{2 4 )}䛿௦ ᥙ 䛝 ᫬ ᮇ 䠄15 ᪥ 㛫 䠅䛾ở ⃮ ㈇ Ⲵ ὶ ฟ 㔞 䛿 䠈₤ ₅ ᮇ 㛫 䠄131 ᪥ 㛫 䠅䛾㈇ Ⲵ 㔞 䛾 TN 䛷 24%䠈 TP 䛷 22%䛻┦ ᙜ 䛩䜛䛸ሗ ࿌ 䛧䛶䛔䜛䚹䜎䛯䠈㕥 ᮌ 䜙 ^{2 5 )}䛿⢓ ᅵ ㉁ ㌿ ᥮ ⏿ 䛻䛚䛔䛶⾜ 䛳 䛯 ᬯ Ὼ ὶ ฟ Ỉ ୰ 䛾 ᠱ ⃮ ែ 䝸 䞁 䠄PP䠅 䜢ㄪ ᰝ 䛧 䛶䛔 䜛 䚹 ୍ ⯡ ⓗ 䛻 䛿 ᠱ ⃮ ᡂ ศ 䛿 ᅵ ተ ෆ 䜢⛣ ື 䛧䛺䛔 䛜 䠈 ⢓ ᅵ ㉁ ㌿ ᥮ ⏿ 䛷 䛿 Ỉ ⏣ 䛛䜙 䛾 ⏿ ㌿ ᥮ 䛻 క 䛖 ஝ ⇱ 䛻 䜘䜚ୗ ᒙ ᅵ 䛻 ட

⿣ 䛜Ⓨ 㐩 䛧䛶䛔䜛஦ 䛜ከ 䛔 䚹䛣䛾⤖ ᯝ 䠈㝆 㞵 ᫬ 䛾 PP 䛾ᬯ Ὼ 䜈䛾ὶ ฟ 㔞 䛿⾲ 㠃 ὶ ฟ 䜢ୖ ᅇ 䛳 䛶䛔䛯 䚹䛭䛾 ௚ 䛻䜒 ⫧ ᩱ 䛾 ✀ 㢮 䜔 㔞 䠈᫬ ᮇ 䜔 ᪋ ⫧ ᪉ ἲ ➼ 䛾ྛ ✀ ᮲ ௳ 䛻䜘䛳 䛶Ỉ ㉁ 䜈䛾ᙳ 㡪 䛿␗ 䛺䜛䛸⪃ 䛘䜙䜜䜛 䚹

ᆅ ᙧ 䛻䜘䜛Ỉ ㉁ 䜈䛾ᙳ 㡪 䛸䛧䛶䛿䠈Hill^{2 6 )}䜔Cirmo^{2 7 )}䛻䜘䛳䛶 䠈ᖹ ᆠ ᆅ 䛾῱ ὶ ࿘ ㎶ 㒊 䛷 䛿⬺ ❅ 䛾 ᙳ 㡪 䛜 ኱ 䛝 䛔 䛸ᣦ ᦬ 䛥䜜 䛶䛔䜛 䚹䛧䛛䛧 䠈Ohrui et al.^{2 8 )}䛻 䜘䜜 䜀 䠈ᛴ ഴ

ᩳ ᆅ 䛷 䛿ᑿ ᰿ ➼ 䛾 Ỉ 䛿䛡䛾 Ⰻ 䛔 ሙ ᡤ 䛻 ẚ 䜉 䛶 䠈㇂ ➽ ➼ 䛾 Ἑ ᕝ ࿘ ㎶ 㒊 䛷 ↓ ᶵ ໬ 䛒 䜛 䛔 䛿 ◪ ໬ 䛾 ๭ ྜ 䛜 㧗 䛔 ஦ 䛜 ሗ ࿌ 䛥䜜 䛶䛔 䜛 䚹䛣䛾 䜘 䛖䛻 ᆅ ᙧ 䛿┤ ᥋ ⓗ 䛻 Ỉ ㉁ 䛻 ᙳ 㡪

5

䜢୚ 䛘䜛䛾䛷 䛺䛟䠈Ỉ 䛾 ὶ 䜜 䛾㐪 䛔䛻䜘䜛ᕼ 㔘 䛒䜛䛔䛿ᅵ ተ ୰ 䛾⫧ ᩱ ᡂ ศ ➼ 䛸䛾᥋ ゐ 䛻 䜘 䜛 ⃰ ⦰ 䠈ᅵ ተ 䛾 Ỉ ศ ᮲ ௳ 䠈  ᗘ 䛻 䜘 䛳 䛶 ᨭ 㓄 䛥䜜 䜛 ◪ ໬ 䜔 ⬺ ❅ ά ᛶ ➼ 䛾 ⤖ ᯝ 䛸 䛧䛶䠈Ἑ ᕝ Ỉ ㉁ 䛻ᑐ 䛧䛶 㛫 ᥋ ⓗ 䛺ᙳ 㡪 䜢୚ 䛘䛶䛔䜛䛸⪃ 䛘䜙䜜䜛䚹

䛣 䛾 䜘 䛖 䛻 㠀 ≉ ᐃ ở ᰁ ※ 䛾 䛂 㠀 ᆒ ㉁ ᛶ 䛃 䛸 䛿 䠈 ㈇ Ⲵ ※ 䛸 䛺 䜛 ᅵ ᆅ ฼ ⏝ 䛛 䜙 ᤼ ฟ 䛧 䛯 N,P ㈇ Ⲵ 䛜 ᅵ ተ 䞉 ᳜ ⏕ 䞉 ᆅ ᙧ 䞉䛒䜛 䛔䛿⫧ ᇵ ⟶ ⌮ ➼ 䛾 ே Ⅽ ⓗ ᮲ ௳ 䛸䛔䛳䛯 ⎔ ቃ ᅉ Ꮚ 䛾ᙳ 㡪 䜢ཷ 䛡䛶Ỉ ㉁ 䛻ኚ ໬ 䜢ᘬ 䛝㉳ 䛣䛩䠈୰୰ 㛫 䝥䝻䝉䝇 䛻䜘䛳䛶䜒䛯䜙䛥䜜䜛䚹

1-1-2.

㠀 ≉ ᐃ ở ᰁ ※ 䛾㠀 ᐃ ᖖ ᛶ 䛻᭱ 䜒኱ 䛝䛺ᙳ 㡪 䜢୚ 䛘䜛䛾䛿 䠈㝆 㞵 ᫬ ฟ Ỉ 䛷䛒䜛 ^{1 7 )}䚹 ᶓ ⏣ 䜙 ^{2 9 )}䛿ὶ ᇦ 㠃 ✚ 57km² 䛾 2 ⣭ Ἑ ᕝ 䜢ᑐ ㇟ 䛸䛧䛶䠈඲ 268 ᪥ 䛾ᐃ ᮇ ㄪ ᰝ 䛸 18 ᅇ 䛾㝆 㞵 ᫬ ㄪ ᰝ 䜢⾜ 䛔 䠈㝆 㞵 ᫬ ㈇ Ⲵ 㔞 䛿ᖹ Ỉ ᫬ 䛻ᑐ 䛧䛶 TN 䛿 30 ಸ ⛬ ᗘ 䠈TP 䛿 100 ಸ ௨ ୖ 䛸ሗ ࿌ 䛧䛶䛔䜛䚹Ṋ ⏣ 䜙 ^{3 0 )}䛿ὶ ᇦ 㠃 ✚ 911km² 䛾ᩫ ఀ ᕝ 䛻䛚䛔䛶䠈㐌 1 ᅇ 䛾㢖 ᗘ 䛷 ⾜ 䛳䛯Ỉ ㉁ ㄪ ᰝ 䜢䜒 䛸䛻 3 ᖺ 㛫 䛾ở ⃮ ㈇ Ⲵ ὶ ฟ 㔞 䜢᥎ ᐃ 䛧䛯 䚹ᖺ 㛫 㝆 Ỉ 㔞 䛾᭱ ኱ ್ 䛸᭱ ᑠ ್ 䛷䛿⣙ 1.8 ಸ 䛾ᕪ 䛰䛳䛯䛜 䠈ὶ ฟ ㈇ Ⲵ 㔞 䛷䛿 TN 䛜 2.6 ಸ 䠈 TP 䛜 2.2 ಸ 䛾ᕪ 䛜䛒䛳䛯䚹኱ ஂ ಖ 䜙 ^{3 1 )}䛿₤ ₅ ᮇ 䛾Ỉ ⏣ ⩌ 䛻䛚䛔䛶ᖹ ᖖ ᫬ 䛻䛿 1 ᪥ 1~2ᅇ 䠈㝆 㞵 ᫬ 11䜲䝧 䞁䝖䜢ᑐ ㇟ 䛸䛧䛯ㄪ ᰝ 䛷 䠈㝆 㞵 ᫬ ὶ ฟ 䛜₤ ₅ ᮇ 䛾㈇ Ⲵ ὶ ฟ 䛾 5๭ ㏆ 䛟䜢༨ 䜑䛶䛔䛯䚹ᅵ ᆅ ฼ ⏝ 䜢㝈 ᐃ 䛧䛶䜒䠈㧗 㢖 ᗘ 䛾Ỉ ㉁ ㄪ ᰝ 䜢㝆 㞵 ᫬ 䜒ྵ 䜑䛶

⾜ 䛔 ᖺ 㛫 䛾 ⥲ ὶ ฟ ㈇ Ⲵ 㔞 䜢 ồ 䜑 䛯 ஦ ౛ 䛿 ᑡ 䛺 䛔 䚹 䜎 䛧 䛶 䜔 䠈 ኱ つ ᶍ Ἑ ᕝ 䛷 䛾 ஦ ౛ 䛿 ᴟ 䜑 䛶 ᑡ 䛺 䛔 䛯 䜑 䠈 ୖ グ 䛾 ◊ ✲ 䛿 㝆 㞵 ᫬ ฟ Ỉ 䛜 Ἑ ᕝ Ỉ ㉁ 䛻 ኱ 䛝 䛺 ᙳ 㡪 䜢 ୚ 䛘 䛶 䛔䜛஦ 䜢♧ 䛩㈗ 㔜 䛺䝕䞊䝍䛷䛒䜛䛸ゝ 䛘䜛䚹

ྛ ᆅ 䛾ᣦ ᐃ † ἟ 䛻䛚䛡䜛㝆 㞵 ᫬ ㄪ ᰝ 䛾ྲྀ 䜚⤌ 䜏䜢ぢ 䜛䛸 䠈2011䠈2013ᖺ ᗘ 䛾ㄶ ゼ

† 䛻 䛚 䛡 䜛 㠀 ≉ ᐃ ở ᰁ ※ ㈇ Ⲵ 㔞 ㄪ ᰝ 䛷 䛿 䠈 ᒣ ᯘ 䠈 Ỉ ⏣ 䠈 ⏿ 䠈 ᕷ ⾤ ᆅ 䛸 ᅵ ᆅ ฼ ⏝ ᙧ

ែ ู 䛻ㄪ ᰝ 䜢⾜ 䛔䠈඼ 䚻䛾ㄪ ᰝ ᆅ Ⅼ 䛷䛿 2 ᅇ 䛾㝆 㞵 ᫬ ㄪ ᰝ 䜢ᐇ ᪋ 䛧䛶䛔䜛 3 2 , 3 3 )䚹

඲ ㄪ ᰝ ᆅ Ⅼ 䜢ే 䛫䛯㝆 㞵 ᫬ ㄪ ᰝ 䛾ᅇ ᩘ 䛿2ᖺ ే 䛫䛶15ᅇ 䛰䛳䛯䚹༳ ᪠ ἟ 䛻䛚䛔䛶 䛿䠈2002 ᖺ ᗘ 䛻䛿ィ 11 ᆅ Ⅼ 䛾㝆 㞵 ᫬ ㄪ ᰝ 䜢 1ᅇ 䠈2004ᖺ ᗘ 䛻䛿 8 ᆅ Ⅼ 䛾㝆 㞵 ᫬ ㄪ ᰝ 䜢 2 ᅇ ᐇ ᪋ 䛧䛶䛔 䜛 3 4 , 3 5 )䚹

㠀 ≉ ᐃ ở ᰁ ※ ᑐ ⟇ 䛾 ᥎ 㐍 䛻 ಀ 䜛 䜺䜲䝗䝷䜲䞁 䛷 䛿 䠈㝆 㞵 ᫬ ㄪ ᰝ 䛾 㢖 ᗘ 䛻 䛴 䛔 䛶㒔

6

ᕷ ཬ 䜃᳃ ᯘ ᆅ ᇦ 䛷䛿ᖺ 4-6 ᅇ ௨ ୖ 䠄ᅄ Ꮨ 䛾 ྛ Ꮨ 1 ᅇ ௨ ୖ 䛷ྜ ィ 4 ᅇ ௨ ୖ 䠅䠈㎰ ᴗ ᆅ ᇦ 䛷䛿ᖺ 3-5 ᅇ ௨ ୖ 䠄Ỉ ⏣ 䛾ሙ ྜ 䛿௦ ᥙ 䛝ᮇ 䠈௦ ᥙ 䛝ᚋ 䠈㠀 ₤ ₅ ᮇ 䛾ྛ ᮇ 1 ᅇ ௨ ୖ 䛷ྜ ィ 3 ᅇ ௨ ୖ 䚹⏿ స 䞉ᶞ ᅬ ᆅ 䞉∾ ⲡ ᆅ 䛷䛿 䠈㝆 㞵 ᫬ 䛾ὶ ฟ ㈇ Ⲵ 䛜୺ య 䛸䛺䜛

஦ 䛛 䜙 䠈ㄪ ᰝ ᅇ ᩘ 䜢 ቑ 䜔 䛩 䛾 䛜 ᮃ 䜎 䛧䛔 䠅 䜢 ᥎ ዡ 䛧 䛶䛔 䜛 ^{3 6 )}䚹 㝆 㞵 ᫬ ὶ ฟ 䛿㝆 㞵 ᙉ ᗘ 䜔ඛ ⾜ ᬕ ኳ ᪥ ᩘ 䛷䜒㈇ Ⲵ ὶ ฟ 䛜ኚ ໬ 䛩䜛䛸䜒ᣦ ᦬ 䛥䜜䛶䛚䜚 ^{3 7 )}䠈ᖺ 䛻 1,2 ᅇ 䛾㝆 㞵 ᫬ ㄪ ᰝ 䛷 䛿 䛭 䛾 ௦ ⾲ ᛶ 䛜 ␲ 䜟 䜜 䜛 䛜 䠈 ᥃ 䛛䜛 ປ ຊ 䛾 ኱ 䛝 䛥 䜔 ㈝ ⏝ ➼ 䛾 ほ Ⅼ 䛛 䜙 䠈

⌮ ᝿ 䛸䛿䛛䛡㞳 䜜䛶䛔䜛䛾䛜ᐇ ≧ 䛷䛒䜛䚹

㝆 㞵 ௨ እ 䛻 㠀 ᐃ ᖖ ᛶ 䜢୚ 䛘 䜛 䜒 䛾䛸 䛧䛶䛿 䠈Ꮨ ⠇ ኚ ໬ 䛻 క 䛖₤ ₅ ⏝ Ỉ 䛾 ᙳ 㡪 䛜 ኱ 䛝 䛔 䚹Ṋ ⏣ 䜙 ^{3 8 )}䛿 ᆅ ୗ ᾐ ㏱ 䛾 ኱ 䛝 䛔 Ỉ ⏣ ⩌ 䜢 ᑐ ㇟ 䛻 ₤ ₅ ᮇ 䛸 㠀 ₤ ₅ ᮇ 䜢 ẚ ㍑ 䛧 䛶 䛔䜛䚹₤ ₅ ᮇ 㛫 䛾⥲ ὶ ධ Ỉ 㔞 䛿㠀 ₤ ₅ ᮇ 䛾 6 ಸ ௨ ୖ 䜒䛒䜚䠈ᖺ 㛫 䛾ᕪ ᘬ ᤼ ฟ ㈇ Ⲵ 㔞 䠄 ⏝ Ỉ ౪ ⤥ 䛻 䜘䛳䛶ὶ ධ 䛩 䜛 ㈇ Ⲵ 㔞 䜢㝖 䛔䛯 ṇ ࿡ 䛾 ㈇ Ⲵ 㔞 䠅 䛻 ༨ 䜑 䜛 㠀 ₤ ₅ ᮇ 䛾

๭ ྜ 䛿 TN䠈TP 䛷 71%䠈12%䛸䛺䛳䛯䚹኱ ஂ ಖ 䜙 ^{3 1 )}䛜Ỉ ⏣ ⩌ 䛾᤼ Ỉ ㊰ 䛷⾜ 䛳䛯㧗 㢖 ᗘ Ỉ ㉁ ㄪ ᰝ 䛷䛿䠈TN䛾ᕪ ᘬ ᤼ ฟ ㈇ Ⲵ 㔞 䛿㠀 ₤ ₅ ᮇ 䛾᪉ 䛜₤ ₅ ᮇ 䜘䜚䜒኱ 䛝䛺㈇ Ⲵ 㔞 䛸䛺䛳䛶䛔䛯䚹TN 䛻䛴䛔䛶䛿ᑐ ↷ ⓗ 䛺⤖ ᯝ 䛷䛒䜛䛜䠈₤ ₅ ⏝ Ỉ ௨ እ 䛾ᙳ 㡪 䜢᤼ 㝖 䛷 䛝 䛺䛔 䛯䜑 䠈ṇ ☜ 䛺ẚ ㍑ 䛿䛷 䛝 䛺䛔 䚹䛧䛛䛧 䠈 ₤ ₅ ⏝ Ỉ 䛜 㝆 㞵 㔞 䛾ᩘ ಸ 䛻 ༉ ᩛ 䛩 䜛 Ỉ 㔞 䜢 ౪ ⤥ 䛧 䛶䛚 䜚 䠈 䛭 䛾 ሙ 䛾 Ἑ ᕝ ⎔ ቃ 䛻 㠀 ᖖ 䛻 ኱ 䛝 䛺ᙳ 㡪 䜢୚ 䛘 䜛 ஦ 䛿 㛫 㐪 䛔 䛺 䛔䛸⪃ 䛘䜙䜜䜛䚹

䜎 䛯 ᫬ 㛫 䝇 䜿 䞊 䝹 䜢 㛗 䛟 䛸 䜜 䜀 䠈 㠀 ≉ ᐃ ở ᰁ ※ 䛛 䜙 䛾 ᤼ ฟ ㈇ Ⲵ 㔞 䛿 ᑡ 䛧 䛪 䛴 ኚ ໬ 䛧 䛶 䛔 䜛 䚹 ౛ 䛘 䜀 ⮬ ື ㌴ 䛾 ᤼ Ẽ 䜺 䝇⏤ ᮶ 䛾 ❅ ⣲ 㓟 ໬ ≀ 䠄NOx䠅 䛾 㔞 䛿 ₞ ῶ 䛧 䛶 䛔 䜛 䛧 䠈 Ỉ ⏣ 䛷 䛿 ᪋ ⫧ 㔞 䜒 ✀ 㢮 䜒 ኚ ໬ 䛧 䛶 䛝 䛶 䛔 䜛 ^{3 9 )}䚹 㠀 ≉ ᐃ ở ᰁ ※ 䛾 㠀 ᐃ ᖖ ᛶ 䛻 䛿 䠈 㝆 㞵 䛻 క 䛖 ▷ ᮇ ኚ ື 䠈 Ꮨ ⠇ ኚ ໬ 䛻 క 䛖 ୰ ᮇ ኚ ື 䠈 䛭 䛧 䛶 ⤒ ᖺ ኚ ໬ 䛻 క 䛖 㛗 ᮇ ኚ ື 䛜

ྵ 䜎䜜䜛䚹

䛣 䛾 䜘 䛖 䛻 㠀 ≉ ᐃ ở ᰁ ※ 䛾 䛂 㠀 ᐃ ᖖ ᛶ 䛃 䛸 䛿 䠈 ㈇ Ⲵ ※ 䛸 䛺 䜛 ᅵ ᆅ ฼ ⏝ 䛛 䜙 ᤼ ฟ 䛧 䛯 N,P ㈇ Ⲵ 䛜୰ 㛫 䝥䝻䝉 䝇 ➼ 䛾 ᙳ 㡪 䜢ཷ 䛡䛺䛜 䜙 䠈㝆 㞵 䜔 ₤ ₅ ⏝ Ỉ 䛸䛔 䛳䛯 ⎔ ቃ ᅉ Ꮚ 䛜ᘬ 䛝㉳ 䛣䛩䠈Ỉ 㔞 䛾᫬᫬ 㛫 ኚ ື 䛻䜘䜚䜒䛯䜙䛥䜜䛯䜒䛾䛷䛒䜛䚹

7

1-1-3.

䛣 䛖 䛧 䛯 㐣 ཤ 䛾 ◊ ✲ ౛ 䜢䜎 䛸 䜑 䛶 䜏 䜛 䛸 䠈 㠀 ≉ ᐃ ở ᰁ ※ 䛻 㠀 ᆒ ㉁ ᛶ 䜢୚ 䛘 䛶 䛔 䜛 䛾 䛿䠈Ⓨ ⏕ 䞉 ᤼ ฟ ㈇ Ⲵ 䛾㐪 䛔 䛻 ຍ 䛘 䛶 䠈Ἑ ᕝ ὶ ฟ 䛻 ⮳ 䜛䜎 䛷䛾 Ỉ ㉁ 䛻ኚ ື 䜢୚ 䛘 䜛 䜘 䛖 䛺๪ ḟ ⓗ 䛺ᅉ Ꮚ 䛜 䠈㔜 せ 䛺ᙺ ๭ 䜢ᯝ 䛯 䛧 䛶䛔䜛 ஦ 䛿᫂ ⓑ 䛷䛒䜛 䚹䛻䜒 㛵 䜟䜙䛪 䛣䛖䛧䛯 ᙳ 㡪 䛜 ᫂ 䜙 䛛䛻 䛥䜜 䛯 ὶ ᇦ 䛿 䠈ᑠ 䛥䛟 㝈 䜙䜜 䛯 ᩘ ὶ ᇦ 䜢ᑐ ㇟ 䛸 䛧䛯 䜒 䛾 䛜 䜋䛸 䜣䛹䛷 䛒 䛳䛯 䚹䜎䛯 䠈㠀 ≉ ᐃ ở ᰁ ※ 䛻㠀 ᐃ ᖖ ᛶ 䜢୚ 䛘 䛶䛔䜛 䛾 䛿䠈㝆 㞵 ᫬ ὶ ฟ 䛜䛭䛾 ୺ 䛯 䜛䜒 䛾 䛷 䛒 䜛 ஦ 䛿௨ ๓ 䜘䜚 ▱ 䜙䜜 䛶䛔 䛯 䚹䛧䛛䛧 䠈㝆 㞵 ᫬ ㄪ ᰝ 䛻 ಀ 䜛 ປ ຊ 䜔 㐺 ษ 䛺ㄪ ᰝ 䛾 㞴 䛧䛥䛛䜙䝕䞊䝍䛿䛒䜎䜚⵳ ✚ 䛥䜜䛶䛣䛺䛛䛳䛯䚹

䛭䛖䛧䛯 Ꮫ ⾡ ⓗ ▱ ぢ 䛾 ✵ ⓑ 㡿 ᇦ 䜢ᇙ 䜑 䠈㠀 ≉ ᐃ ở ᰁ ※ 䛾ὶ ฟ ㈇ Ⲵ 䛾 ண   ⢭ ᗘ 䜢

ୖ 䛢 䜛 䛯 䜑 䛻 䠈 ᮏ ㄽ ᩥ 䛷 䛿 䠈 䐟䐟 ᾐ ㏱ 䞉 ὶ ฟ 䝥 䝻 䝉 䝇 䛻 ᙳ 㡪 䛩 䜛 ྛ ✀ ⎔ ቃ ᅉ Ꮚ 䛸 ὶ ฟ 㔞 䛾 㛵 ಀ ᛶ 䛾 ゎ ᫂ 䠈䐠 ከ ᵝ 䛺⁐ Ꮡ 䞉 ᠱ ⃮ ᡂ ศ 䛻 ᑐ 䛧䛶 䛾 㝆 㞵 ฟ Ỉ ᫬ 䛾 ὶ ฟ 㔞 䜈 䛾 ᙳ 㡪 䜢᫂ 䜙䛛䛸 䛩䜛 ஦ 䜢┠ ⓗ 䛸䛧䛶◊ ✲ 䜢⾜ 䛳䛯䚹

ᾐ ㏱ 䞉 ὶ ฟ 䝥 䝻 䝉 䝇 䛾 ホ ౯ 䜢 ⾜ 䛖 䛻 䛿 䠈 䜰 䜴 䝖 䝥 䝑 䝖 䛷 䛒 䜛 Ἑ ᕝ Ỉ ㉁ 䛛 䜙 ゎ ᯒ 䜢 ⾜ 䛖 䜟 䛡 䛰 䛜 䠈 䛭 䛾 ๓ ẁ 䛷 䛒 䜛 Ⓨ ⏕ 䞉 ᤼ ฟ ㈇ Ⲵ 㔞 䛸 ᾐ ㏱ 䞉 ὶ ฟ 䝥 䝻 䝉 䝇 䛾 ᙳ 㡪 䛜 ධ 䜚 ΰ 䛨 䛳䛶Ἑ ᕝ Ỉ ㉁ 䛿ᙧ ᡂ 䛥 䜜 䛶䛔 䜛 䚹 䛣䛾 Ἑ ᕝ Ỉ ㉁ 䛛䜙ᾐ ㏱ 䞉 ὶ ฟ 䝥䝻 䝉 䝇 䛾 ᙳ 㡪 䜢᫂ 䜙 䛛䛸 䛩 䜛 䛯 䜑 䛻 䛿 䠈 Ⓨ ⏕ 䞉 ᤼ ฟ ㈇ Ⲵ 㔞 䛜 ṇ ☜ 䛻 ぢ ✚ 䜒 䜙䜜 䛶䛔 䜛 ஦ 䛜 ๓ ᥦ ᮲ ௳ 䛸 䛺䜛 䚹 䛭 䛣䛷 䐟䛻䛴 䛔 䛶 䛿䠈䜎䛪 Ⓨ ⏕ ※ ゎ ᯒ ᡭ ἲ 䛾ホ ౯ 䜢⾜ 䛔 䠈⥆ 䛔 䛶ᾐ ㏱ 䞉 ὶ ฟ 䝥䝻䝉 䝇 䛾 ゎ ᯒ 䜢 ⾜ 䛳 䛯 䚹 ᾐ ㏱ 䞉 ὶ ฟ 䝥 䝻 䝉 䝇 䛻 䛿 䠈 ᆅ ᙧ 䞉 ᆅ ㉁ 䞉 ᅵ ተ 䞉 ᳜ ⏕ ➼ 䛾 ᵝ 䚻 䛺 ⎔ ቃ ᅉ Ꮚ 䛜 ᙳ 㡪 䛧 䛶 䛔 䜛 䛸 ⪃ 䛘 䜙 䜜 䜛 䛯 䜑 䠈 䝸 䝰 䞊 䝖 䝉 䞁 䝅 䞁 䜾 䠄RS䠅 䜔 ᆅ ⌮ ᝟ ሗ 䝅 䝇 䝔 䝮 䠄GIS䠅 䜢㥑 ౑ 䛧䛶ᩚ ഛ 䛧䛯ὶ ᇦ ⎔ ቃ ᝟ ሗ 䛸ከ ὶ ᇦ 䛾ᐇ   䝕䞊䝍 䜢⏝ 䛔䛶⤫ ィ ゎ ᯒ 䜢

⾜ 䛳䛯䚹

䜎 䛯 䐠 䛻 䛴 䛔 䛶 䛿 䠈 㝆 㞵 ᫬ ㄪ ᰝ 䜢 ᗈ ᇦ 䛷 ᩘ ከ 䛟 ᐇ ᪋ 䛩 䜛 ஦ 䛜 ⌮ ᝿ 䛷 䛒 䜛 䛜 䠈 ᥃ 䛛 䜛ປ ຊ 䛾 ၥ 㢟 䛛䜙ᐇ ⌧ 䛩䜛䛾䛿ᅔ 㞴 䛷䛒 䜛 䚹䛭 䛣䛷 Ⓨ ᝿ 䜢ኚ 䛘 䛶 䠈᪤ Ꮡ 䛾䝰䝙䝍䝸䞁䜾 䝕䞊䝍䛛䜙㝆 㞵 ᫬ ὶ ฟ ᡂ ศ 䜢ᢳ ฟ 䛩䜛᪉ ἲ 䜢ᥦ ᱌ 䛧䛯䚹ල య ⓗ 䛻䛿᫬ ⣔ ิ ศ ᯒ 䛾 1 ᡭ ἲ 䛷 䛒 䜛 ⛣ ື ᖹ ᆒ ἲ 䜢 ⏝ 䛔 䛶 䠈 㝆 㞵 䛾 ᙳ 㡪 䜢 ཷ 䛡 䛯 ᡂ ศ 䜢 ศ 㞳 䛧 䠈 ⁐ Ꮡ ཬ 䜃 ᠱ

⃮ ᡂ ศ 䛾ὶ ฟ ≉ ᛶ 䛾ኚ ໬ 䜢 ゎ ᯒ 䛧䛯䚹

8

1-2. ㄽ ㄽ ᩥ 䛾ᵓ ᡂ

ᮏ ㄽ ᩥ 䛿䠈N,P 䛾Ἑ ᕝ ὶ ฟ 䝥䝻䝉䝇䛾ゎ ᯒ 䜢┠ ⓗ 䛸䛧䛯䜒䛾䛷䛒䜚 䠈඲ 5 ❶ 䛛䜙ᵓ ᡂ 䛥䜜䜛䚹ྛ ❶ 䛾ᴫ せ 䜢௨ ୗ 䛻グ 䛩䚹

➨2❶ 䛷䛿䠈N,PⓎ ⏕ ※ ゎ ᯒ ᡭ ἲ 䛾ホ ౯ 䜢⾜ 䛳䛯䚹䜎䛪㟘 䞄ᾆ 䛾Ỉ ㉁ ಖ ඲ ィ ⏬ 䛷

฼ ⏝ 䛥䜜䛶䛔䜛ཎ ༢ ఩ 䛾 ☜ 䛛䜙䛧䛥䛻䛴䛔䛶᳨ ド 䜢⾜ 䛳䛯䠄2-1 ⠇ 䠅䚹ḟ 䛻⤫ ィ ⓗ 䛺ᡭ ἲ 䜢⏝ 䛔䛶ᅵ ᆅ ฼ ⏝ ู ὶ ฟ ཎ ༢ ఩ 䜢ồ 䜑 䠈㠀 ≉ ᐃ ở ᰁ ※ 䛛䜙䛾N,P㈇ Ⲵ 䛾Ꮨ ⠇ ኚ

ື 䛻䛴䛔䛶ゎ ᯒ 䛧䛯 䠄2-2 ⠇ 䠅 䚹ྛ ᅵ ᆅ ฼ ⏝ 䛛䜙䛾㈇ Ⲵ 䜢✚ 䜏ୖ 䛢䛶䛔 䛟 ཎཎ ༢ ఩ ἲ 䛻 ᑐ 䛧䛶䠈ᅵ ᆅ ฼ ⏝ 䛻㈇ Ⲵ 䜢๭ 䜚ᡠ 䛩 ὶὶ ฟ ཎ ༢ ఩ 䛸䛔䛖␗ 䛺䜛䜰䝥䝻䞊 䝏䜢ẚ ㍑ 䛩䜛 ஦ 䛷 ὶ ᇦ 䛛 䜙 䛾 N,P ㈇ Ⲵ 䛾 Ⓨ ⏕ 䞉 ᤼ ฟ ㈇ Ⲵ 䛾 ᥎ ᐃ ᪉ ἲ 䛻 䛴 䛔 䛶 ᨵ ၿ ᥦ ᱌ 䜢 ⾜ 䛳 䛯 䠄2-3 ⠇ 䠅

➨ 3 ❶ 䛷䛿䠈N,P 䛾ᾐ ㏱ 䞉ὶ ฟ 䝥䝻䝉䝇䛾ゎ ᯒ 䜢⾜ 䛳䛯䚹Ⓨ ⏕ 䞉᤼ ฟ 䛥䜜䛯 N,P 䛜 Ἑ ᕝ 䛻 ὶ ฟ 䛩 䜛 䜎 䛷 䛻 ᙳ 㡪 䜢 ཬ 䜌䛩 䛸 ⪃ 䛘 䜙 䜜 䜛 ⎔ ቃ せ ᅉ 䠄 ᳜ ⏕ 䞉 ᆅ ᙧ 䞉 ᅵ ተ 䞉 ᆅ ㉁ 䠅 䛾 ᙳ 㡪 䛻 䛴 䛔 䛶 ᳨ ウ 䛧 䛯 䚹 䛣 䜜 䜙 䛾 ⎔ ቃ せ ᅉ 䛿 Ⓨ ⏕ 䞉 ᤼ ฟ ㈇ Ⲵ 䛾 䜘 䛖 䛻 Ἑ ᕝ Ỉ ㉁ 䜢 つ ᐃ 䛩䜛䜘 䛖䛺୺ ᅉ 䛷䛿䛺䛟 䠈Ἑ ᕝ Ỉ ㉁ 䛻ኚ ື 䜢୚ 䛘䜛 䜘䛖䛺๪ ḟ ⓗ 䛺ᅉ Ꮚ 䛷䛒䜛 䚹 䜎 䛪 ᒣᒣ 㛫 ᆅ 䠄 ᳃ ᯘ 䠅 䜢 ᑐ ㇟ 䛸 䛧 䛶 ᅵ ᆅ ฼ ⏝ 䛸 ᅵ ተ 䜢 㝈 ᐃ 䛩 䜛 ஦ 䛷 䠈 ᅵ ᆅ ฼ ⏝ 䛸 ᅵ ተ 䛻 㛵 䛩 䜛 ᮲ ௳ 䜢୍ ᐃ 䛻 䛧 䠈ᆅ ᙧ ཬ 䜃 ᳜ ⏕ 䠄 ᶞ ✀ 䠅 䛜 ῱ ὶ Ỉ ㉁ 䛻 ཬ 䜌䛩 ᙳ 㡪 䛻 䛴䛔 䛶 ゎ ᯒ 䜢⾜ 䛳䛯䠄3-1 ⠇ 䠅 䚹 ḟ 䛻ᖹᖹ ᆠ ᆅ 䠄 ㎰ ᆅ 䠅 䜢ᑐ ㇟ 䛸䛧䛶ᅵ ተ 䛾䝸䞁㓟 ྾ ╔ ≉ ᛶ 䛾 㐪 䛔 䛻 ╔ ┠ 䛧䛶 䠈ᅵ ተ ᆺ 䛷ὶ ᇦ 䜢ศ 㢮 䛩䜛 ஦ 䛷 䠈ᅵ ተ 䛜Ἑ ᕝ Ỉ ㉁ 䛻 ୚ 䛘䜛 ᙳ 㡪 䛻 䛴䛔 䛶 ゎ ᯒ 䛧䛯 䠄3-2 ⠇ 䠅 䚹㈇ Ⲵ ὶ ฟ 䝥䝻䝉 䝇 䛾 ␗ 䛺䜛᳃ ᯘ 䛸 ㎰ ᆅ 䛻 䛴䛔 䛶䛾ゎ ᯒ 䛛䜙 䠈䛣䜜 䜎 䛷 ホ ౯ 䛜 㞴 䛧 䛛 䛳 䛯 ๪ ḟ ⓗ 䛺 ⎔ ቃ ᅉ Ꮚ 䛾 ᙳ 㡪 䜢 ᳨ ฟ 䛩 䜛 䛯 䜑 䛾 ゎ ᯒ ᡭ ἲ 䛻 䛴 䛔 䛶⪃ ᐹ 䜢⾜ 䛳䛯䠄3-3 ⠇ 䠅䚹

➨ 4 ❶ 䛷䛿䠈㝆 㞵 ᫬ ฟ Ỉ 䛜 N,P ὶ ฟ 䝥䝻䝉䝇䛻୚ 䛘䜛ᙳ 㡪 䛻䛴䛔䛶ゎ ᯒ 䜢⾜ 䛳䛯䚹 Ἑ ᕝ 䜈䛾㈇ Ⲵ ὶ ฟ 䛻䛚 䛔䛶 䠈ᖹ Ỉ ᫬ 䛸㝆 㞵 ᫬ 䛷䛿␗ 䛺䜛 ᣲ ື 䜢♧ 䛩 ஦ 䛜▱ 䜙䜜䛶䛔 䜛 䚹 䛧 䛛 䛧 䠈 㝆 㞵 ᫬ Ἑ ᕝ ㄪ ᰝ 䛿 ከ ኱ 䛺 ປ ຊ 䜢 ᚲ せ 䛸 䛧 䠈 ㄪ ᰝ ᫬ 䛾 ༴ 㝤 ᛶ 䜒 ኱ 䛝 䛔 ஦ 䛛 䜙䠈ㄪ ᰝ ஦ ౛ 䛜 㝈 䜙䜜䛶䛔䜛 䚹䛭 䛣䛷 䠈᭶ ౛ 䛾Ἑ ᕝ Ỉ ㉁ 䝰 䝙䝍䝸 䞁䜾䛾䝕 䞊䝍䛻 ᫬ ⣔

ิ ศ ᯒ 䜢⾜ 䛖஦ 䛷 䠈㝆 㞵 䛾ᙳ 㡪 䜢ཷ 䛡䛯ᡂ ศ 䜢ᢳ ฟ 䛩䜛ᡭ ἲ 䜢ᥦ ᱌ 䛧䛯䠄4-1⠇ 䠅 䚹䛣

9

䛾 ⤖ ᯝ 䛛 䜙 䠈 ฟฟ Ỉ ᫬ 䛻 䛚 䛡 䜛 Ἑ ᕝ ὶ ฟ 䝥 䝻 䝉 䝇 䛜 䛹 䛾 䜘 䛖 䛻 ኚ ໬ 䛧 䛯 䛛 䜢 ⪃ ᐹ 䛧 䛯 䠄4-2 ⠇ 䠅䚹

➨ 5 ❶ 䛿⤖ ㄽ 䛸䛧䛶ྛ ❶ 䛻䛚䛡䜛ᡂ ᯝ 䜢 2 䛴䛾ど Ⅼ 䛛䜙⥲ ᣓ 䛧䛯䚹ጞ 䜑䛻 䠈N,P 䛾 Ἑ ᕝ ὶ ฟ 䝥 䝻䝉 䝇䛾 ◊ ✲ 䛸 䛧 䛶䛾 Ꮫ ⾡ ศ 㔝 䜈 䛾 ㈉ ⊩ 䠄5-1 ⠇ 䠅 䜢 グ ㏙ 䛧 䛯 䚹 ḟ 䛻 䠈 ⾜ ᨻ ➼ 䛷 ⾜ 䜟 䜜 䛶 䛔 䜛 ὶ ᇦ ⎔ ቃ 䝬 䝛 䞊 䝆 䝯 䞁 䝖 䜈 䛾 ᮏ ◊ ✲ 䛾 ㈉ ⊩ 䠄5-2 ⠇ 䠅 䛻 䛴 䛔 䛶 䜒 グ ㏙ 䛧䛯䚹

10

1-3. ␎ ␎ ㄒ ୍ ぴ

COD : Ch e mi c al o x yg e n d e man d : ໬ Ꮫ ⓗ 㓟

⣲ せ ồ 㔞 N: N itro gen : ❅ ⣲ P : P h o sp h o ru s: 䝸 䞁 C: C arbon: Ⅳ ⣲

NO x: Nitro g en O xid es : ❅ ⣲ 㓟 ໬ ≀ NH3: Am moni a: 䜰 䞁 䝰 䝙 䜰

SS: Susp en d ed Solid: ᾋ 㐟 ᠱ ⃮ ≀ ㉁ Chl-a : Chloroph yll a: 䜽 䝻 䝻 䝣 䜱 䝹 a TN: To tal Ni tro gen : ඲ ❅ ⣲

P N: P articul at e Ni tro gen : ᠱ ⃮ ែ ❅ ⣲ P ON: P aticu l ate Organ i c Nitro g en : ᠱ ⃮ ែ

᭷ ᶵ ❅ ⣲

D TN: Di sso l v ed To t al Nit ro g en : ⁐ Ꮡ ែ ❅

⣲

DO N: D i s so l ved Org an i c Ni t ro g en : ⁐ Ꮡ ែ

᭷ ᶵ ❅ ⣲

DIN : Di sso l v ed In o rg an i c Ni t ro gen : ⁐ Ꮡ

ែ ↓ ᶵ ❅ ⣲

NO_x-N: ◪ 㓟 䞉 ள ◪ 㓟 ែ ❅ ⣲

NO₃-N: Nit ra te n itro gen : ◪ 㓟 ែ ❅ ⣲ NO2-N: Nit rit e nit rogen: ள ◪ 㓟 ែ ❅ ⣲ NH4-N: Am moni a nitro ge n : 䜰 䞁 䝰 䝙 䜰 ែ ❅

⣲

TP : To t al P hosphorus : ඲ 䝸 䞁

PP : P articulat ed P hosphorus: ᠱ ⃮ ែ 䝸 䞁 D TP : Dis so l v ed To t a l P h o sp h o ru s : ⁐ Ꮡ ែ

䝸 䞁

DOP : Di s so l v ed Organ i c P h o sp h o ru s : ⁐ Ꮡ

ែ ᭷ ᶵ 䝸 䞁

P O4-P : P hosphate phospho ru s: 䝸 䞁 㓟 ែ 䝸 䞁 TO C: To ta l Organic C arbo n : ඲ ᭷ ᶵ Ⅳ ⣲ P OC : P at i cu l a t ed Org an i c Carb o n : ᠱ ⃮ ែ

᭷ ᶵ Ⅳ ⣲

DOC : Dis so l v ed Org an i c C arb o n : ⁐ Ꮡ ែ

᭷ ᶵ Ⅳ ⣲

Cl^-: Chro line: ሷ ⣲ 䜲 䜸 䞁 SO4-: Sul fat e ion: ◲ 㓟 䜲 䜸 䞁 NO₃^-: Ni tr ate ion: ◪ 㓟 䜲 䜸 䞁 Na⁺: Sodiu m ion: 䝘 䝖 䝸 䜴 䝮 䜲 䜸 䞁 K⁺: P o ta ssiu m ion: 䜹 䝸 䜴 䝮 䜲 䜸 䞁

M g⁺: Ma gn es iu m ion: 䝬 䜾 䝛 䝅 䜴 䝮 䜲 䜸 䞁 Ca⁺: C al ciu m ion: 䜹 䝹 䝅 䜴 䝮 䜲 䜸 䞁 NH4+: Am moniu m ion: 䜰 䞁 䝰 䝙 䜴 䝮 䜲 䜸 䞁

S . D.: S t an d a rd D e vi at i o n : ᶆ ‽ ೫ ᕪ V IF: Varian ce In fl atio n Fac to r : ศ ᩓ ᣑ ኱

ಀ ᩘ

T W I: To p o g rap h i c Wet n es s In d e x : ᆅ ᙧ ⓗ 䛺 ‵ ₶ ᣦ ᶆ

DEM : D e git al E l e vat i o n M o d el : ᩘ ್ ᶆ 㧗 䝰 䝕 䝹

RS: R e mo te S ens ing : 䝸 䝰 䞊 䝖 䝉 䞁 䝅 䞁 䜾 GIS : Geo g rap h i c In fo r ma t i o n S ys te m: ᆅ ⌮

᝟ ሗ 䝅 䝇 䝔 䝮

P an: P anchro mati c : 䝟 䞁 䜽 䝻 䠄 ⓑ 㯮 䠅 MS: Multisp e ctr al : 」 ᩘ Ἴ 㛗 Ne ar IR: Ne ar In fr ar ed : ㏆ ㉥ እ

RP C: Rat io n al P o l yn o mi n al Co e ffi ci en ts :

᭷ ฼ ከ 㡯 ᘧ ಀ ᩘ

HEC: H yd ro l o g i c E n gin ee ri n g C en t er s : ⡿ ᅜ 㝣 ㌷ ᕤ ර 㝲 Ỉ ᩥ ᕤ Ꮫ 䝉 䞁 䝍 䞊

USEPA: US En viron m en ta l P rote ction Ag en c y: ⡿ ᅜ ⎔ ቃ ಖ ㆤ ┬

HSP F: H yd r o l o gi ca l S i mu l at i o n P ro gr a m Fo rtru n

SWAT: Soil & Wat er As se s men t Tool : Ỉ ᅵ ተ 䜰 䝉 䝇 䝯 䞁 䝖 䝒 䞊 䝹

AD W: An t ec ed en t Dr y We ath e r d a y n u mb e r : ඛ ⾜ ᬕ ኳ ᪥ ᩘ

AR: An te c edent Ra in fa ll: ඛ ⾜ 㝆 㞵

AP I: An t ed ec en t P re ci p i t a t i o n In d ex : ඛ ⾜ 㝆 㞵 ᣦ ᩘ

WL: Wat er Le vel: Ỉ ఩

P DC A: P lan Do Ch e c k Act io n : ィ ⏬ 䞉 ᐇ ⾜ 䞉 ホ ౯ 䞉 ᨵ ၿ

1

11

➨

➨ 2❶ ❅ ⣲ 䞉䝸䞁 Ⓨ ⏕ ※ ゎ ᯒ ᡭ ἲ 䛾ホ ౯

ὶ ᇦ 䛛 䜙 䛾 ở ⃮ ㈇ Ⲵ ᥎ ᐃ ᪉ ἲ 䛸 䛧 䛶 䛿 䠈 ཎ ༢ ఩ ἲ 䛻 䜘 䜛 㞟 Ỉ ᇦ 䛛 䜙 䛾 Ⓨ ⏕ ※ ู

᤼ ฟ ㈇ Ⲵ 㔞 䛾⟬ ᐃ 䜔 ὶ ฟ Ἑ ᕝ ㈇ Ⲵ 㔞 ᐇ   ἲ 䠄 Ἑ ᕝ ὶ ฟ 䛂LQ ᘧ 䛃 䠅䛻䜘䜛 † ἟ ➼ 䜈 䛾ὶ ฟ ㈇ Ⲵ 㔞 䛾⟬ ᐃ 䛾 2 䛴䛜௦ ⾲ ⓗ 䛷䛒䜛 ^{3 6 )}䚹

ཎ ༢ ఩ ἲ 䛿 ᐇ   䝕 䞊 䝍 䛜 ஈ 䛧 䛟 䛶 䜒 ὶ ᇦ 䛛 䜙 䛾 ở ⃮ ㈇ Ⲵ 㔞 䜢 ᥎ ᐃ 䛩 䜛 ஦ 䛜 ྍ ⬟ 䛷 䛒 䜛 䚹䜎 䛯 䠈௚ ᆅ ᇦ 䛾 ᪤   ཎ ༢ ఩ 䜢௦ ⏝ 䛩 䜛 ஦ 䛻 䜘䛳䛶䠈 ㄪ ᰝ ㈇ ᢸ 䜢 ኱ 䛝 䛟 ప ῶ 䛷 䛝䜛≉ ᚩ 䜢ᣢ 䛴䚹䛣䜜䛻ᑐ 䛧䛶䠈Ἑ ᕝ ὶ ฟ 䛂LQ ᘧ 䛃䛿ᐇ   䛾ὶ 㔞 䞉Ỉ ㉁ ㄪ ᰝ 䛻ᇶ 䛵䛔 䛯 ㏆ ఝ ᘧ 䜢⏝ 䛔 䛶 䠈 㐃 ⥆ ほ   䛾 ὶ 㔞 䛛 䜙 † ἟ ➼ 䜈 䛾 ὶ ධ ㈇ Ⲵ 㔞 䜢ண   䛩 䜛 ᪉ ἲ 䛷 䠈 ཎ ༢ ఩ ἲ 䜘 䜚⢭ ᗘ Ⰻ 䛟 ᐇ ែ 䜢ᤊ 䛘 䜛 ஦ 䛜 䛷 䛝 䜛 䚹Ἑ ᕝ ὶ ฟ 䛂LQ ᘧ 䛃 䛿 Ἑ ᕝ ᤼ ฟ 䛛䜙

† ἟ 䜈 䛾 ὶ ฟ 䜎䛷 䜢ྵ 䜑 䛯 ್ 䛷 䛒䜛䛜 䠈ෆ ໟ 䛩䜛 㠀 ≉ ᐃ ở ᰁ ※ 䛛䜙䛾 ㈇ Ⲵ 䛾 ෆ ヂ 䜢 ศ 㞳 䛩 䜛 ஦ 䛜 䛷 䛝 䛺䛔 䚹䛣 䛾 䛯 䜑 Ἑ ᕝ 䜈 䛾 ㈇ Ⲵ ὶ ฟ 䝥 䝻䝉 䝇 䜢 ᳨ ウ 䛩 䜛 䛯 䜑 䛻 䛿 䠈 Ⓨ

⏕ ※ 䛾᥎ ᐃ 䛜䛷䛝䜛ཎ ༢ ఩ ἲ 䛾ண   ⢭ ᗘ 䜢㧗 䜑䜛஦ 䛻䜘䜚䚸ὶ ฟ 䝥䝻 䝉䝇䛻䛚䛡䜛Ỉ

㉁ 䜈䛾ᙳ 㡪 䜢ᢕ ᥱ 䛩䜛ᚲ せ 䛜䛒䜛䚹

ཎ ༢ ఩ ἲ 䛿 ὶ ᇦ ෆ 䛻 䛚 䛡䜛 ㈇ Ⲵ 䛾 ✵ 㛫 ศ ᕸ 䜢 ᢕ ᥱ 䛩 䜛 ஦ 䛜 䛷 䛝 䠈⌧ ≧ 䛾 ホ ౯ 䛰 䛡 䛷 䛺 䛟 ᑐ ⟇ 䜢 ㅮ 䛨 䛯 ሙ ྜ 䛾 ᨵ ၿ ຠ ᯝ 䛾 ண   䛜 ྍ ⬟ 䛺 䛯 䜑 䠈 † ἟ Ỉ ㉁ ಖ ඲ ≉ ู ᥐ

⨨ ἲ ^{7 )}䛻ᇶ 䛵䛟 11 䛾ᣦ ᐃ † ἟ 䛾† ἟ Ỉ ㉁ ಖ ඲ ィ ⏬ 䛻 ⏝ 䛔䜙䜜䛶䛔䜛 4 0 , 4 1 )䚹䜎䛯䠈 ཎ ༢ ఩ 䛿† ἟ 䛾Ỉ ㉁ 䝅䝭 䝳䝺䞊 䝅䝵䞁 䝰䝕 䝹䛾䝟䝷䝯䞊 䝍 䛸 䛧䛶฼ ⏝ 䛥䜜䜛஦ 䜒䛒 䜚䠈ὶ ᇦ ⟶ ⌮ 䛻䛚䛔䛶㔜 せ 䛺ᙺ ๭ 䜢ᢸ 䛳䛶䛔䜛4 2 , 4 3 )䚹䛻䜒䛛䛛䜟䜙䛪䠈ཎ ༢ ఩ 䛿స ᡂ 䛥䜜䛯 ᆅ ᇦ ≉ ᛶ 䠈 ㄪ ᰝ ᫬ ᮇ 䛒 䜛 䛔 䛿 ᖺ ௦ 䛻 䜘 䛳 䛶 ኱ 䛝 䛟 ␗ 䛺 䜛 ஦ 䛛 䜙 䠄Fig.2-1䠅 䠈 ୍ ᚊ 䛻 ゎ ᯒ 䛻⏝ 䛔䜛஦ 䛿኱ 䛝䛺ၥ 㢟 䜢Ꮞ 䜣䛷䛔䜛䚹䛣䛾䛯䜑䠈䛂㠀 ≉ ᐃ ở ᰁ ※ ᑐ ⟇ 䛾᥎ 㐍 䛻ಀ 䜛 䜺䜲䝗䝷䜲䞁 䛃 䛷 䛿 䠈௚ ᆅ ᇦ 䛾 ཎ ༢ ఩ 䜢௦ ⏝ 䛩 䜛 㝿 䛿ៅ 㔜 䛺㐺 ⏝ 䛜 ồ 䜑 䜙䜜 䛶䛚 䜚 䠈 䛭 䛾 ୖ 䛷 䠈Ἑ ᕝ ὶ ฟ 䛂LQ ᘧ 䛃 䛸 䛾 ẚ ㍑ 䛻 䜘䜚ཎ ༢ ఩ 䛾 ጇ ᙜ ᛶ 䜢᳨ ウ 䛩 䜛 ஦ 䛜 ⸀ 䜑 䜙

䜜䛶䛔䜛 ^{3 6 )}䚹

䛧䛛䛧䠈ཎ ༢ ఩ ἲ 䛻䜘䜚⟬ ฟ 䛥䜜䛯 ㈇ Ⲵ ⥲ ᤼ ฟ 㔞 䛸 LQ ᘧ 䛻䜘䜛⥲ ὶ ฟ 㔞 䛾ᕪ 䛛䜙䠈 䛒 䜛 ⛬ ᗘ 䛾 䜽 䝻 䝇 䝏 䜵 䝑 䜽 䛿 ྍ ⬟ 䛰 䛜 䠈 ྛ ✀ 䛾 㠀 ≉ ᐃ ở ᰁ ※ 䛛 䜙 䛾 ㈇ Ⲵ ᥎ ᐃ 䛾 ⢭ ᗘ

12

ホ ౯ 䜎 䛷 䛿⾜ 䛖஦ 䛜䛷䛝䛺䛔䚹 䛣䜜 䛷䛿⥲ 㔞 䛾 ᩘ ್ 䜢 䝣䜱 䝑 䝔䜱 䞁 䜾 䛧䛶䛔䜛 䛰 䛡䛷 䠈ཎ ༢ ఩ 䛾☜ 䛛䜙䛧䛥䛾᰿ ᣐ 䛻䛿䛺䜚ᚓ 䛺䛔䚹

ᮏ ❶ 䛷䛿 䠈Ⓨ ⏕ 䞉 ᤼ ฟ ※ 䛾ண   ᡭ ἲ 䛷 䛒䜛ཎ ༢ ఩ ἲ 䛻䛴䛔 䛶⪃ ᐹ 䛧 䠈䛭䛾 ᨵ Ⰻ 䜔 ᛂ ⏝ 䛾 ྍ ⬟ ᛶ 䛻䛴 䛔䛶᳨ ウ 䛩䜛 䚹䜎䛪 䠈㟘 䞄ᾆ 䛾† ἟ Ỉ ㉁ ಖ ඲ ィ ⏬ 䛷 ฼ ⏝ 䛥䜜 䛶䛔 䜛 㠀 ≉ ᐃ ở ᰁ ※ 䛾 ཎ ༢ ఩ 䛾 ☜ 䛛䜙 䛧 䛥䛻 䛴 䛔 䛶 ᳨ ド 䜢⾜ 䛳䛯 䠄2-1 ⠇ 䠅 䚹ḟ 䛻 䠈 ᅵ ᆅ

฼ ⏝ 㠃 ✚ 䛸 Ἑ ᕝ 䛾 ᐇ   Ỉ ㉁ 䛛䜙⤫ ィ ⓗ 䛻 ὶ ฟ ཎ ༢ ఩ 䜢ồ 䜑 䜛 ᪉ ἲ 䛻䛴 䛔 䛶᳨ ド 䛧 䛯䠄2-2 ⠇ 䠅 䚹㠀 ≉ ᐃ ở ᰁ ※ 䛾 ཎ ༢ ఩ 䛜ᅵ ᆅ ฼ ⏝ ẖ 䛾㈇ Ⲵ 䜢✚ 䜏ୖ 䛢䜛 Bottom up

ⓗ 䛺ᡭ ἲ 䛰䛸䛩䜜䜀䠈ὶ ฟ ཎ ༢ ఩ 䛿 Top downⓗ 䛺ᡭ ἲ 䛰䛸ゝ 䛘䜛䚹䛣䛾ど Ⅼ 䛾␗ 䛺 䜛䜰䝥䝻䞊䝏䜢ẚ ㍑ 䛩䜛஦ 䛷 䠈௒ ᚋ 䛾ὶ ᇦ ⟶ ⌮ 䛾Ỉ ⎔ ቃ ᨵ ၿ 䛻㈨ 䛩䜛䛷䛒䜝䛖 䠈ὶ ᇦ 䛛䜙䛾 N,P 䛾Ⓨ ⏕ 䞉᤼ ฟ ㈇ Ⲵ 䛾᥎ ᐃ ᪉ ἲ 䛻䛴䛔䛶ᥦ ᱌ 䜢⾜ 䛳䛯䠄2-3 ⠇ 䠅䚹

13

Fig.2-1 Averages and ranges of pollutant unit loadings used for the lakes designated in the lake water qualit y conservation plan and listed in the comprehensive basin -wide planning of sewerage system^{3 6 )}.

14

2-1. GIS 䜢 䜢⏝ 䛔䛯ὶ ᇦ ⟶ ⌮ : ཎ ༢ ఩ ἲ 䜢⏝ 䛔䛶⟬ ᐃ 䛧䛯᤼ ฟ ㈇ Ⲵ 㔞 䛾ホ ౯

2-1-1.

† ἟ Ỉ ㉁ ಖ ඲ ≉ ู ᥐ ⨨ ἲ 䛾ไ ᐃ 䛛䜙 30 ᖺ ௨ ୖ ⤒ 㐣 䛧䛶䛔䜛䛻䜒㛵 䜟䜙䛪䠈† ἟ Ỉ ㉁ 䛿ᨵ ၿ 䛾ഴ ྥ 䛜ぢ 䜙䜜䛪䠈⏕ ά ⎔ ቃ 㡯 ┠ 䛻ಀ 䜟䜛⎔ ቃ ᇶ ‽ 䛾㐩 ᡂ ⋡ 䜒40䠂ྎ

䛻 ␃ 䜎 䛳䛶䛔 䜛 䚹† ἟ ἲ 䛷 䛿ὶ ධ ㈇ Ⲵ 䛾 ๐ ῶ 䛻 䛴 䛔 䛶䠈 ᪋ ⟇ ྍ ⬟ 䛺ᑐ ⟇ 䜢ㅮ 䛨䛯 ሙ

ྜ 䛾䝅䝭䝳䝺䞊䝅䝵䞁䜢⾜ 䛔䠈䛭䛾⤖ ᯝ 䜢Ỉ ㉁ ┠ ᶆ ್ 䛸䛧䛶ᥖ 䛢䛶䛔䜛䚹ୗ Ỉ 㐨 䛾ᩚ ഛ

➼ 䛾 ⏕ ά ᤼ Ỉ ᑐ ⟇ 䜔ᕤ ሙ 䞉 ஦ ᴗ ሙ 䛾᤼ Ỉ つ ไ 䛸 䛔 䛳䛯 ஦ ᴗ ィ ⏬ 䛿ண ᐃ ㏻ 䜚䛻 ᐇ ⾜ 䛥䜜 䛶䛚 䜚 䠈 † ἟ 䜈 䛾 ὶ ධ ㈇ Ⲵ 䛿๐ ῶ 䛧 䛶䛔 䜛 䛻 䜒 㛵 䜟 䜙䛪 䠈Ỉ ㉁ ┠ ᶆ ್ 䛻 㐩 䛧䛺䛔

† 䛜ከ 䛟ぢ 䜙䜜䜛 ^{4 4 )}䚹

䛣䛾ཎ ᅉ 䛸䛧䛶3䛴䛾ྍ ⬟ ᛶ 䛜⪃ 䛘䜙䜜䜛䚹㻌 䐟† ἟ 䜈䛾እ 㒊 䛛䜙䛾ὶ ධ ㈇ Ⲵ 䛾 ぢ

✚ 䜚 䛜 㛫 㐪 䛳 䛶 䛔 䜛 䚹 㻌 䐠 እ 㒊 䛛 䜙 䛾 ὶ ධ ㈇ Ⲵ 䛻 ẚ 䜉 䛶 † ἟ 䛾 ෆ 㒊 ⏕ ⏘ 䛻 䜘 䜛 ㈇ Ⲵ 䛾๭ ྜ 䛜኱ 䛝䛟䛺䛳䛶䛔䜛䚹㻌 䐡Ẽ ೃ ኚ ື 䛜† ἟ Ỉ ㉁ 䛻኱ 䛝䛺ᙳ 㡪 䜢୚ 䛘䛶䛔䜛䚹

୰ 䛷䜒䠈䐟 እ 㒊 䛛䜙䛾 ὶ ධ ㈇ Ⲵ 䛾ぢ ✚ 䜚䛿† ἟ Ỉ ㉁ ಖ ඲ ィ ⏬ ❧ ᱌ 䛾 ᇶ ♏ 䛷䛒䜚䠈 ὶ ᇦ ⟶ ⌮ 䛾 ᰿ ᖿ 䜢䛺䛩㒊 ศ 䛷 䛒䜛 ஦ 䛛䜙᪩ ᛴ 䛺᳨ ド 䛜 ᚲ せ 䛷䛒䜛 䚹እ 㒊 䛛䜙䛾 ὶ ධ

㈇ Ⲵ 㔞 䛿 䠈 ཎ ༢ ఩ ἲ 䛷 ✚ 䜏 ୖ 䛢䛯 ㈇ Ⲵ 㔞 䛻 ὶ ฟ ⋡ 䜔 䝰 䝕 䝹 ᘧ 䜢 㐺 ⏝ 䛧 䛶 ồ 䜑 䜙 䜜

䜛^{4 4 )}䚹ᚑ 䛳䛶䠈ཎ ༢ ఩ ἲ 䛷ồ 䜑䛯㈇ Ⲵ 㔞 䛜ṇ ☜ 䛻ぢ ✚ 䜒䜙䜜䛶䛔䜛 ஦ 䛜๓ ᥦ 䛸䛺䛳䛶

䛔 䜛 䛜 䠈䛭 䛾 㒊 ศ 䛾 ᳨ ド 䛿䛒 䜎 䜚⾜ 䜟 䜜 䛶䛔 䛺 䛔 䚹 ཎ ༢ ఩ 䛾 ⢭ ᗘ ᳨ ド 䜢⾜ 䛖䛯 䜑 䛻 䛿䠈 ὶ ฟ ⋡ 䜔䝰䝕䝹ᘧ ➼ 䜢௓ 䛥䛺䛔ᑠ 䛥䛺ὶ ᇦ 䛷 ゎ ᯒ 䜢⾜ 䛖ᚲ せ 䛜䛒䜛䚹䛧䛛䛧䠈䛣䜜䜎䛷 䛿ᕷ ⏫ ᮧ ➼ 䛾⾜ ᨻ ⏺ 䜢䝧䞊䝇䛸䛧䛶◊ ✲ 䛜⾜ 䜟䜜䛶䛝䛯䛯䜑 ^{4 5–4 9 )}䠈ᑐ ㇟ 㠃 ✚ 䛜኱ 䛝 䛟䠈ཎ ༢ ఩ ἲ 䛻䜘䜛ぢ ✚ 䜚䛾 ṇ ☜ ᛶ 䛻㛵 䛩䜛┤ ᥋ ⓗ ᳨ ド 䛿䜋䛸䜣䛹⾜ 䜟䜜䛶䛔䛺䛔 䚹

䛭 䛣䛷 ᮏ ⠇ 䛷 䛿 䠈ཎ ༢ ఩ ἲ 䛷 ồ 䜑 䛯 ㈇ Ⲵ 㔞 䛾 ṇ ☜ ᛶ 䛻 䛴 䛔 䛶 ᳨ ド 䜢 ⾜ 䛖䛯 䜑 䛻 䠈 GIS 䜢฼ ⏝ 䛧䛶ᑐ ㇟ ὶ ᇦ 䜢⣽ ศ ໬ 䛩䜛஦ 䛷䠈ண   Ỉ ㉁ 䛸ᐇ   Ỉ ㉁ 䛾 ẚ ㍑ 䜢ヨ 䜏䛯䚹 䜎 䛯 䛭 䛾 ⤖ ᯝ 䛛 䜙 䠈 㟘 䞄ᾆ 䛷 ᐇ 㝿 䛻 ồ 䜑 䜙 䜜 䛯 † ἟ ἲ 䛾 ✚ ୖ 䛢 ㈇ Ⲵ 㔞 䛻 䛴 䛔 䛶 䜒 ⪃ ᐹ 䜢⾜ 䛳䛯䚹

15

2-1-2.

㸦 1 㸧 *,6

㟘 䞄ᾆ ὶ ᇦ 䛾䛴䛟 䜀 ᕷ 䠈ᅵ ᾆ ᕷ ཬ 䜃 㜿 ぢ ⏫ 䜢ᑐ ㇟ ᆅ ᇦ 䛸 䛧䛶᳨ ウ 䜢⾜ 䛳䛯 䚹ᑐ ㇟ ᆅ ᇦ 䛾ὶ ᇦ 㠃 ✚ 䛿410 km²䛷䠈20 䛾Ἑ ᕝ 䛜ὶ 䜜䛶䛔䜛䚹䛭䛾䛖䛱17 Ἑ ᕝ 䛜㟘 䞄ᾆ 䛻 ὶ ධ 䛧 䛶 䛚 䜚 䠈 ṧ 䜚 䛿 ∵ ஂ ἟ 䛻 ὶ ධ 䛧 䛶 䛔 䜛 䚹 䛣 䛾 ὶ ᇦ 䛻 䛴 䛔 䛶 ᅜ ໃ ㄪ ᰝ 䜢 ᇶ ‽ 䛸 䛧 䛯2,733 䛾䝴䝙䝑䝖䛻༊ ศ 䛧 GIS ୖ 䛻ᩚ ⌮ 䛧䛯 䚹ᚑ ᮶ 䛾GIS 䜢⏝ 䛔䛯ὶ ᇦ ゎ ᯒ 䛷䛿 1 䛴 䛾Ἑ ᕝ ὶ ᇦ 䜢༢ ఩ 䛸 䛧䛶㈇ Ⲵ 㔞 ィ ⟬ 䜢⾜ 䛖᪉ ἲ 䛜 ከ 䛟 ぢ 䜙䜜 䜛 ^{4 5–4 9 )}䚹䛣䛾 ᪉ ἲ 䛷 䛿Ἑ ᕝ ẖ 䛻 ở ⃮ ㈇ Ⲵ 㔞 䛾 ⥲ 㔞 ⓗ 䛺 ẚ ㍑ 䛿ྍ ⬟ 䛷 䛒 䜛 䛜 䠈 䝢䞁 䝫 䜲䞁 䝖 䛺 ở ᰁ ※ 䛾 ≉ ᐃ 䛿ᅔ 㞴 䛷䛒䜛䚹

ở ᰁ ※ 䛾 ≉ ᐃ 䛻 䛿 䠈 ở ⃮ ㈇ Ⲵ 䜢 ᤼ ฟ 䛩 䜛 ᭱ ᑠ 䛾 ༢ ఩ 䛜 ே 䛷 䛒 䜛 䛯 䜑 䠈 ಶ ே 䜢 ᭱ ᑠ ༢ ఩ 䛸䛧䛶⪃ 䛘䜛䛾䛜᭱ 䜒Ⰻ 䛔᪉ ἲ 䛷䛒䜛 䚹䛧䛛䛧䠈ே 䛾ά ື 䛿 1 䛴 䛾ሙ ᡤ 䛻䛸䛹䜎 䛳 䛶 䛔 䜛 ヂ 䛷 䛿 䛺 䛔 䛯 䜑 䠈 ้ 䚻 䛸 ኚ ໬ 䛩 䜛 ✵ 㛫 ᗙ ᶆ 䜢 ᢕ ᥱ 䛩 䜛 ஦ 䛿 ᅔ 㞴 䛷 䛒 䜛 䚹 䛭 䛣 䛷 ⏕ ά 䛾 ᇶ ♏ ༢ ఩ 䛷䛒䜛 ᐙ 䛜✵ 㛫 ᗙ ᶆ 䜢≉ ᐃ 䛷 䛝䜛 ᭱ ᑠ ༢ ఩ 䛸 ⪃ 䛘 䜙䜜 䜛 䚹ྛ ᡞ ู 䛾ே ཱྀ 䝕䞊䝍䛿ධ ᡭ 䛷䛝䛺䛛䛳䛯䛾䛷䠈ᅜ ໃ ㄪ ᰝ ༊ ᅗ 䛸ᅵ ᆅ ฼ ⏝ ᮲ ௳ ᅗ 䜢GISୖ 䛷 䜸䞊䝞䞊䝺䜲䛩䜛஦ 䛷䠈ྛ ᅜ ໃ ㄪ ᰝ ༊ ෆ 䠄ᖹ ᆒ 㠃 ✚ 䛿0.2km²⛬ ᗘ 䠅䛻 Ꮡ ᅾ 䛩䜛ఫ Ꮿ

⏝ ᆅ ཬ 䜃 ే ⏝ ఫ Ꮿ ⏝ ᆅ 㠃 ✚ 䛻ᑐ 䛩䜛ே ཱྀ ᐦ ᗘ 䜢ィ ⟬ 䛧䛯䚹䛣 䛾᪉ ἲ 䛻䜘䜚䠈㠃 ✚ ᱌ ศ 䛾 ⢭ ᗘ 䜢 ᚑ ᮶ 䜘 䜚䜒 ྥ ୖ 䛥䛫 䛯 䠈ఫ Ꮿ ⏝ ᆅ ẖ 䛾 ே ཱྀ 䜢 ⟬ ฟ 䛧䠈 ே ཱྀ ᝟ ሗ 䛾 ᭱ ᑠ 䝣 䝺䞊 䝮 䛸 䛧䛶฼ ⏝ 䛧䛯 䚹ྠ ᵝ 䛺᪉ ἲ 䛷 䜸䞊 䝞 䞊䝺䜲䛧䛶 ⣽ ศ ๭ 䛧䛯 ྛ ᅵ ᆅ ฼ ⏝ 㠃 ✚ 䜢 㠀 ≉ ᐃ ở ᰁ ※ 䛛䜙䛾㈇ Ⲵ ィ ⟬ 䛾᭱ ᑠ 䝣䝺䞊䝮䛸䛧䛯䚹

䝕 䞊 䝍 㞟 ィ ༢ ఩ 䜢 Ἑ ᕝ 䛻 䛩 䜛 䛸 䠈 Ἑ ᕝ ᮎ ➃ 䛻 䛚 䛡 䜛 Ἑ ᕝ Ỉ ㉁ 䛿 ண   䛷 䛝 䜛 䛜 䠈ὶ ᇦ 䛾ఱ ฎ 䛷ᑐ ⟇ 䜢⾜ 䛖 䛾䛜䠈㈇ Ⲵ ๐ ῶ ຠ ᯝ 䛜㧗 䛔䛾䛛䛜୙ ᫂ 䛷䛒䜛 䚹䛭䛣䛷䠈Ἑ ᕝ 䛾 ᨭ ὶ 䜢㞟 ィ 䛾ᇶ ᮏ ༢ ఩ 䛸䛧䛶䠈᭱ ᑠ 䝣䝺䞊䝮䛾䝕 䞊䝍䜢75䛾ᑠ ὶ ᇦ ẖ 䛻෌ 㞟 ィ 䜢⾜

䛳䛯䚹

౑ ⏝ 䛧䛯䝕䞊䝍䛿1995ᖺ 䛾㒔 ᕷ ィ ⏬ ᇶ ♏ ㄪ ᰝ 䛸ᅜ ໃ ㄪ ᰝ 䛻ᇶ 䛵䛟䝕䞊䝍ཬ 䜃ί

໬ ᵴ タ ⨨ ᒆ 䛡➼ 䛾Ⲉ ᇛ ┴ 䜈䛾ᒆ ฟ 䝕䞊䝍䛷䛒䜛 5 0 , 5 1 )䚹

16

㸦 2 㸧 ཎ ༢ ఩ ἲ 䜢⏝ 䛔䛯 Ỉ ㉁ ண  

㈇ Ⲵ 㔞 ィ ⟬ 䛿ཎ ༢ ఩ ἲ 䜢⏝ 䛔 䛶⾜ 䛳䛯 䚹౑ ⏝ 䛧䛯 ཎ ༢ ఩ 䛿Ⲉ ᇛ ┴ 䛻 䛚䛔 䛶౑ ⏝ 䛥䜜䛶䛔䜛䜒䛾䜢౑ 䛳䛯^{4 4 )}䚹⮬ ↛ ⣔ 䠄㎰ ᆅ 䜢ྵ 䜐 㠀 ≉ ᐃ ở ᰁ ※ 䠅䛛䜙䛾㈇ Ⲵ 㔞 䛿⮬ ↛

⣔ ཎ ༢ ఩ 䛻 ᅵ ᆅ ฼ ⏝ ู 㠃 ✚ 䜢 ஌ 䛨 䛶ồ 䜑 䛯 䚹㒔 ᕷ ィ ⏬ ᇶ ♏ ㄪ ᰝ 䛷 䛿ᕷ ⾤ ᆅ 䛸 䛧䛶 බ ᅬ ⥳ ᆅ 䜔 ᩥ ᩍ ᪋ タ ➼ 䜒 ྵ 䜎 䜜 䛶 䛔 䛯 䛜 䠈 ཎ ༢ ఩ 䛾 ༊ ศ 䛻 ᑐ ᛂ 䛥 䛫 䜛 䛯 䜑 䠈 䛣 䛣 䛷 䛿ᕷ ⾤ ᆅ 䛸༊ ู 䛧䛶ྲྀ 䜚ᢅ 䛳䛯 䚹⏕ ά ⣔ 䛻䛴䛔 䛶䛿ฎ ⌮ ᙧ ែ ู ே ཱྀ 䛻ཎ ༢ ఩ 䜢஌ 䛨 䛶ồ 䜑 䛯 䚹஦ ᴗ ᡤ ⣔ 䛻 䛴 䛔 䛶䛿 ᒆ ฟ ᤼ Ỉ 㔞 䛻 㟘 䞄 ᾆ ᐩ ᰤ 㣴 ໬ 㜵 Ṇ ᮲ ౛ 䛻 䜘 䜛 ᪂ タ

஦ ᴗ ᡤ 䜢ᑐ ㇟ 䛸 䛧䛯 ᤼ Ỉ ᇶ ‽ ್ 䜢஌ 䛨䛶ồ 䜑 䛯 䚹ὶ ᇦ ୗ Ỉ 㐨 䜔 බ ඹ ୗ Ỉ 㐨 ฼ ⏝ ே

ཱྀ 䛻 䛴 䛔 䛶 䛿⣔ እ ᤼ ฟ 䛸 䛧 䠈⤊ ᮎ ฎ ⌮ ሙ 䛛䜙䛾 ᤼ Ỉ 䛿 ≉ ᐃ ở ᰁ ※ 䛸 䛧 䛶䠈 ᐇ   䝕 䞊 䝍䜢⏝ 䛔䛶ィ ⟬ 䛧䛯 䚹㎰ ᴗ 㞟 ⴠ ᤼ Ỉ ฎ ⌮ ሙ 䛾฼ ⏝ ே ཱྀ 䛻 䛴䛔 䛶䛿⣔ ෆ ᤼ ฟ 䛸 䛧䠈ᐇ   䝕 䞊 䝍 䛻 ᇶ 䛵 䛟 ཎ ༢ ఩ 䜢⏝ 䛔 䛶 ✚ ⟬ 䛧䛯 ^{5 0 )}䚹␆ ⏘ ⣔ 䛻 䛴 䛔 䛶䛿䠈 ㈨ ᩱ 䛜 ᚓ 䜙䜜 䛺 䛛䛳䛯䛯䜑ィ ⟬ 䛻䛿ຍ 䛘䛶䛔䛺䛔䚹

ὶ ฟ Ỉ 㔞 䛿₤ ₅ ᮇ 䛸 㠀 ₤ ₅ ᮇ 䛻 ศ 䛡䛶✚ ⟬ 䛧䛯 䚹₤ ₅ ᮇ 䛷䛿㝆 Ỉ 䠈⏕ ά ⣔ ᤼ Ỉ 䠈 ཬ 䜃 ㎰ ᴗ ⏝ Ỉ ⏤ ᮶ 䛾ὶ ฟ 㔞 䛾 ࿴ 䜢⥲ ὶ ฟ 㔞 䛸 䛧䛯 䚹㠀 ₤ ₅ ᮇ 䛷 䛿㎰ ᴗ ⏝ Ỉ 䜢㝖 䛔 䛯๓ 2 ⪅ 䛾࿴ 䜢⥲ ὶ ฟ 㔞 䛸䛧䛯䚹⏕ ά ⣔ ᤼ Ỉ 㔞 䛿 1 ே ᙜ 䛯䜚䛾Ỉ ౑ ⏝ 㔞 䜢 300 L person^{- 1} day^{- 1} 䛸䛧䠈⏕ ά ⣔ 㞧 ᤼ Ỉ 䛿 250 L person^{- 1} day^{- 1}䠈ᒉ ᒀ 䛿 50 L person^{- 1} day^{- 1}䛸 䛧䛶ィ ⟬ 䛧䛯䚹₤ ₅ 䛻⏝ 䛔䜛㎰ ᴗ ⏝ Ỉ 䛾౑ ⏝ 㔞 䛿⪺ 䛝ྲྀ 䜚ㄪ ᰝ 䛛䜙 125.5 m³

ha^{- 1} day^{- 1}䛸 䛧䛶ィ ⟬ 䛧䛯䚹₤ ₅ ᮇ 䛿 5 ᭶ 䛛䜙 7 ᭶ 䛸䛧䛯䚹஦ ᴗ ᡤ 䛛䜙䛾⏕ ⏘ 䛻క 䛖᤼

Ỉ 㔞 䛻䛴 䛔 䛶䛿ᒆ ฟ 䝕䞊 䝍䜢౑ ⏝ 䛧䛯 ^{5 0 )}䚹㝆 㞵 ⏤ ᮶ 䛾 ὶ ฟ Ỉ 㔞 䛻 䛴䛔 䛶䛿㝆 Ỉ 㔞 䛛䜙⵨ Ⓨ ᩓ 㔞 䜢ᕪ 䛧ᘬ 䛟 ஦ 䛷ồ 䜑䛯䚹⵨ Ⓨ 㔞 䛿ᅜ ❧ ⎔ ቃ ◊ ✲ ᡤ ᒇ ୖ 䛷Class A pan 䜢⏝ 䛔䛶  ᐃ 䛥䜜䛯䝕䞊䝍䜢⏝ 䛔䛯 ^{5 2 )}䚹ᅵ ᆅ ฼ ⏝ 䛾㐪 䛔䛻ᇶ 䛵䛟⵨ Ⓨ ᩓ 㔞 䜈䛾᥮ ⟬ ಀ ᩘ 䛿㔠 Ꮚ ^{5 3 )}䛾䝕䞊䝍䜢⏝ 䛔䛯䚹⏝ 䛔䛯⵨ Ⓨ 㔞 䛸㝆 Ỉ 㔞 䛾᭶ ู ᖹ ᆒ ್ 䜢 Table 2-1 䛻 䠈Ỉ ⏣ ཬ 䜃 䛭 䛾 ௚ 䛾 ᅵ ᆅ ฼ ⏝ 䛷 䛾 ⵨ Ⓨ ᩓ 㔞 䛻 ᥮ ⟬ 䛩 䜛 䛯 䜑 䛾 ᥮ ⟬ ಀ ᩘ 䜢 Table 2-2 䛻♧ 䛩䚹 ⵨ Ⓨ ᩓ 㔞 䜢㝖 䛔䛯 㝆 㞵 䛿඲ 䛶 Ἑ ᕝ 䜈ὶ ฟ 䛩䜛䛸 ௬ ᐃ 䛧䛯䚹ὶ ฟ Ỉ 䛾ண   ⃰ ᗘ 䛿 ₤ ₅ ᮇ ཬ 䜃 㠀 ₤ ₅ ᮇ 䛾 ⥲ ᤼ ฟ ㈇ Ⲵ 㔞 䜢 ⥲ ὶ ฟ Ỉ 㔞 䛷 㝖 䛧 䛶 ồ 䜑 䛯 䚹 ୖ グ 䛾㞟 ィ ཬ 䜃ィ ⟬ 䛿 GIS 䝋䝣䝖䜴䜵䜰䛾PC-Mapping (Mapcom)䜢౑ ⏝ 䛧䛶⾜ 䛳䛯䚹

17

㸦 3 㸧 ᑠ ὶ ᇦ 䛾ᐇ   Ỉ ㉁ ㄪ ᰝ

75 䛾ᑠ ὶ ᇦ 䛾䛖䛱 55 ᆅ Ⅼ 䛻䛴䛔䛶Ἑ ᕝ ㄪ ᰝ 䜢⾜ 䛳䛯䚹Ἑ ᕝ ẖ 䛾ὶ 㐩 ⋡ 䜔⮬ ί స ⏝ ➼ 䛾ᙳ 㡪 䜢䛺䜛䜉 䛟㝖 䛔䛶ゎ ᯒ 䜢⾜ 䛖䛯䜑 䠈௚ 䛾ὶ ᇦ 䛾ᙳ 㡪 䜢ཷ 䛡䛺䛔 䠈ᨭ ὶ 䛾

᭱ ୖ ὶ 㒊 䛻఩ ⨨ 䛩䜛 20 䛾ᑠ ὶ ᇦ 䛻䛴䛔䛶௨ ୗ 䛷⪃ ᐹ 䛩䜛䚹ㄪ ᰝ 䛿 1999 ᖺ 䛸 2000 ᖺ 䛾 3 ᭶ 䠄㠀 ₤ ₅ ᮇ 䠅 ཬ 䜃 6 ᭶ 䠄₤ ₅ ᮇ 䠅䛻ྜ ィ 4 ᅇ ⾜ 䛳䛯䚹ㄪ ᰝ ⠊ ᅖ 䛜ᗈ ᇦ 䛾 䛯 䜑䠈3 ᪥ 㛫 䛛䛡䛶ㄪ ᰝ 䜢ᐇ ᪋ 䛧䛯 䚹ᘏ 䜉 12 ᪥ 䛾ㄪ ᰝ ᪥ 䛾䛖䛱 4 ᪥ 䛿 0.5䡚9.0mm ⛬ ᗘ 䛾㝆 㞵 䛜䛒䜚䠈ඛ ⾜ 㝆 㞵 䜔ᆅ Ⅼ ẖ 䛾ㄪ ᰝ ᪥ 䛛䜙䠈1999 ᖺ 䛾 6 ᭶ 䜢㝖 䛔䛶㝆 㞵 䛾 ᙳ 㡪 䛜 䛷 䛶 䛔 䜛 ྍ ⬟ ᛶ 䛜 䛒 䛳䛯 䚹 ྛ ᑠ ὶ ᇦ 䛾 ᭱ ୗ ὶ 㒊 䛷 ὶ 㔞   ᐃ ཬ 䜃 ᥇ Ỉ ᚋ 䛻 䠈 ヨ ᩱ 䛿㏿ 䜔䛛䛻ᐇ 㦂 ᐊ 䛻ᣢ 䛱ᖐ 䜚䠈COD䠈TNཬ 䜃 TP ⃰ ᗘ 䛻䛴䛔䛶  ᐃ 䛧䛯䚹Ỉ ㉁ ศ ᯒ 䛿† ἟ ⎔ ቃ ㄪ ᰝ ᣦ 㔪 䛻ᇶ 䛵䛔䛶⾜ 䛳䛯 ^{5 4 )}䚹

ㄪ ᰝ ὶ ᇦ ཬ 䜃ㄪ ᰝ ᆅ Ⅼ 䜢 Fig.2-2 䛻♧ 䛩䚹

Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Paddy field ^{0.45 0.45 0.55 0.60 1.00 1.05 1.25 1.30 1.30 1.20 0.70 0.55}

Others 0.45 0.45 0.55 0.60 0.65 0.70 0.80 0.85 0.85 0.80 0.65 0.55

Table 2-2 C o nv er si o n fa ct or us e d f or e sti ma t i ng t h e ev a p ot r a n s pir a ti o n r a t e i n p a d dy fiel d a nd o t he r l a nd us e are a s ba se d o n e v a por ati o n pa n dat a.

Table 2-1 M o nt hly me a n e v a po r ati o n i n Ts u ku b a d u ri ng 1 9 7 7 -1 9 7 8 a n d mo nt h l y me a n pre ci pit at ion i n Ts uc hi u r a i n 1 9 9 5 .

Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Evaporation volume from

class A pan 0.8 1.1 1.9 2.1 2.8 3.8 3.1 1.9 2.3 1.3 1.1 0.6

Mean Precipitation 0.9 0.6 4.6 3.7 6.1 6.0 5.0 2.2 5.7 2.0 1.3 0.0

(mm day^-1)

18

2-1-3.

㸦 1 㸧 ὶ ᇦ ≉ ᛶ 䛸᤼ Ỉ ฎ ⌮ ᙧ ែ

ㄪ ᰝ 䜢⾜ 䛳䛯 20 䛾ᑠ ὶ ᇦ 䛾㠃

✚ 䠈 ே ཱྀ 䠈 ᅵ ᆅ ฼ ⏝ ཬ 䜃 ᤼ Ỉ ฎ

⌮ ᙧ ែ 䜢 Table 2-3 䛻♧ 䛩䚹ὶ ᇦ 㠃 ✚ 䛿 129䡚2,176ha 䛸 䛛䛺䜚䛾ᖜ 䛜䛒䜛䛜䠈200䡚400ha ⛬ ᗘ 䛾㠃 ✚ 䛾 ὶ ᇦ 䛜 ከ 䛛 䛳䛯 䚹 ᅵ ᆅ ฼ ⏝ 䛿 ᑠ ὶ ᇦ ẖ 䛻 ኱ 䛝 䛟 ␗ 䛺䛳䛶䛚 䜚䠈 ᑠ ὶ ᇦ 8 䛷䛿Ỉ ⏣ 䛾㠃 ✚ 䛜᭱ 䜒ከ 䛟䠈 ᑠ ὶ ᇦ 6䠈14䠈17䠈18䠈19䛷䛿⏿ 䛾 㠃 ✚ 䛜ከ 䛛䛳䛯䚹ᑠ ὶ ᇦ 5 䛷䛿᳃

ᯘ 䛾 ༨ ᭷ ⋡ 䛜 58%䛸 㧗 䛛䛳䛯 䚹ᑠ ὶ ᇦ 2䠈3䠈10䠈13 䛷䛿ᕷ ⾤ ᆅ 䛾༨

᭷ ⋡ 䛜 50%௨ ୖ 䛰䛳䛯䚹ᑠ ὶ ᇦ 9䠈 14䠈15䠈16 䛷䛿䛭䛾௚ 䛾ᅵ ᆅ ฼ ⏝ 䛜ከ 䛛䛳䛯䚹䛭䛾௚ 䛻 䛿䛴䛟䜀ᕷ ෆ 䛻䛒䜛◊ ✲ ᪋ タ 䛜ྵ 䜎䜜䛶䛔䜛䚹

ே ཱྀ ᐦ ᗘ 䛿ᑠ ὶ ᇦ 2䠈9䠈13䛷20 person ha^{- 1}௨ ୖ 䛸䛺䜚䠈ㄪ ᰝ ὶ ᇦ 䛾୰ 䛷䛿ᐦ ᗘ 䛜㧗 䛟䛺䛳䛯䛜䠈䛭䛾௚ 䛾ᆅ ᇦ 䛷䛿10 person ha^{- 1}௨ ୗ 䛾ᡤ 䛜ከ 䛟䠈≉ 䛻 3䡚5 person ha^{- 1}⛬ ᗘ 䛾ே ཱྀ ᐦ ᗘ 䛾ὶ ᇦ 䛜ከ 䛛䛳䛯䚹

⏕ ά ᤼ Ỉ 䛾 ฎ ⌮ ᙧ ែ 䛿ᑠ ὶ ᇦ ẖ 䛷 ኱ 䛝䛟 ␗ 䛺䛳䛶䛔䛯 䚹 ᑠ ὶ ᇦ 6䠈18 䛷 䛿༢ ⊂ ฎ ⌮ ί ໬ ᵴ 䛜40%⛬ ᗘ 䜢༨ 䜑䛶䛔䛯䚹ྜ ే ฎ ⌮ ί ໬ ᵴ 䛿 ᑠ ὶ ᇦ 1䠈4䠈11䛾ὶ ᇦ 䛷

⣙ 20%䛸㧗 䛛䛳䛯䛜䠈䛭䛾௚ 䛷䛿10䠂௨ ୗ 䛾ᡤ 䛜ከ 䛛䛳䛯䚹㎰ ᴗ 㞟 ⴠ ᤼ Ỉ ฎ ⌮ ሙ 䜢

ྵ 䜑䛯ୗ Ỉ 㐨 ฼ ⏝ ே ཱྀ 䛷䛿 ᑠ ὶ ᇦ 9䠈10䠈13 䛷 80%௨ ୖ 䜢༨ 䜑䛶䛔 䛯䚹ᑠ ὶ ᇦ 4䠈 5䠈7䠈20 䛷䛿ᒉ ᒀ 䛾䛟䜏ྲྀ 䜚䛜 60%௨ ୖ 䜢༨ 䜑 䛶䛔䛯䚹

Fig.2-2 M a p o f s ma l l ri v er basi ns i n Ts ukuba, Ts uc hi ura and A mi are a s i n t he La ke K as u mig a ur a ba si n, a nd the s it es f or ef fl ue nt w ater s a mpl i ng . T he numbe r i n Fig indic at es w aters he d nu mbe r.

19

㸦 2 㸧 ὶ 㔞 䛸ᖹ ᆒ 㝆 㞵 㔞 䛾㛵 ಀ 䛻䛴䛔䛶

඼ 䚻 䛾ㄪ ᰝ 䛿 3 ᪥ 㛫 䛻 Ώ 䛳䛶⾜ 䛳䛯䛯 䜑 䠈ㄪ ᰝ ᆅ Ⅼ ẖ 䛻ඛ ⾜ 㝆 㞵 㔞 䛿␗ 䛺䜛 䚹 ㄪ ᰝ ᭱ ⤊ ᪥ 䛛䜙㐳 䛳䛶10᪥ 㛫 䛾ᖹ ᆒ 㝆 㞵 㔞 䜢ィ ⟬ 䛩䜛䛸 1999ᖺ 3᭶ 䛸6᭶ 䠈2000 ᖺ 3 ᭶ 䛷䛿 2mm ๓ ᚋ 䛷䠈2000 ᖺ 6 ᭶ 䛷䛿 10mm ⛬ ᗘ 䛰䛳䛯䚹๓ ⪅ 䛷䛿ㄪ ᰝ ᙜ ᪥ 䛻 䜋䛸 䜣䛹 㝆 㞵 䛿 䛺䛟 䠈 ඛ ⾜ 㝆 㞵 㔞 䜒 ഹ 䛛 䛺䛯 䜑 䠈 䛚 䛚 䜘䛭 ᬕ ኳ ᫬ ὶ 㔞 䛻 ➼ 䛧 䛔 䛸 ุ

᩿ 䛷䛝䜛䚹䛧䛛䛧䠈ᚋ ⪅ 䛷䛿ㄪ ᰝ ᪥ 䛻 4-9mm 䛾㝆 㞵 䛜ほ   䛥䜜䛯䛯䜑 䠈᫂ 䜙䛛䛻㝆 㞵 䛾 ᙳ 㡪 䜢 ཷ 䛡 䛶䛔 䜛 ⤖ ᯝ 䛸 䛺 䛳䛯 䚹

ඛ ⾜ 㝆 㞵 䛾 ᙳ 㡪 䛜 ᭱ 䜒 ᙉ 䛟 ཯ ᫎ 䛥 䜜 䜛 ᪥ ᩘ 䜢 ồ 䜑 䛯 䛸 䛣䜝 䠈3 ᪥ ๓ 䜎 䛷 䛾 ඛ ⾜ 㝆 㞵 㔞 䛾 ᖹ ᆒ ್ 䜢 ⏝ 䛔 䛶 ὶ 㔞 䜢 ᥎ ᐃ 䛧 䛯 ሙ ྜ 䛻 ㄪ ᰝ ᮇ 㛫 䛾 ᖹ ᆒ ὶ 㔞 䛸 䛾 ┦ 㛵 䛜 㧗 䛟 䛺 䛳 䛯 䠄Table 2-4䠅 䚹 䜎 䛯 䛣 䛾 ᫬ 䠈 ᬕ ኳ

᫬ 䛻⾜ 䜟䜜䛯3ᅇ 䛾ㄪ ᰝ 䛷䛿┦ 㛵

Table 2-3 P o p ul a ti o n, p o p ul ati o n de n si ty, l a n d u s e, a n d t he pro p or ti o n o f ty pes o f tre at me nt sy st e ms tre ati ng do me s tic w ast ew ater in t h e s ma ll basi ns st udie d. Sew ag e : publi c sew age tre a t me nt pl a nt ; Nig ht s oil : nig ht s oil tre a t me nt pl a nt .

Paddy Field

Upland

field Forest Urban

area Others Septic tank Combination

septic tank Sewage Night soil

1 420.3 5,686 13.5 14.5 32.9 13.3 33.3 5.4 21.6 22.7 37.6 31.0

2 293.3 9,354 31.9 8.3 11.7 11.9 55.9 12.1 7.0 2.2 75.2 19.2

3 250.2 2,811 11.2 4.2 11.6 8.9 68.8 6.4 12.6 3.9 76.3 14.1

4 503.0 1,883 3.7 11.5 28.6 27.3 29.3 3.3 11.3 20.2 0.0 68.5

5 1720.6 3,319 1.9 15.8 4.8 58.2 10.5 4.8 28.5 6.6 0.0 69.0

6 251.9 793 3.1 10.3 40.9 28.9 17.1 2.8 39.7 6.4 0.0 53.8

7 129.2 300 2.3 9.1 25.1 33.2 22.3 6.2 32.3 6.0 0.0 61.7

8 582.2 2,265 3.9 36.0 10.4 5.8 22.5 23.2 27.4 13.6 43.0 22.7

9 2176.2 43,992 20.2 6.8 15.4 6.4 34.7 36.2 3.6 0.9 81.3 15.8

10 215.4 2,609 12.1 3.3 6.1 2.4 67.1 21.1 33.8 14.8 84.5 3.3

11 690.9 6,197 9.0 21.4 32.8 5.9 29.1 10.8 30.8 19.4 25.8 35.8

12 189.9 1,302 6.9 20.6 31.3 5.2 35.7 7.1 21.0 8.4 47.8 27.3

13 268.4 7,653 28.5 6.6 18.8 2.1 48.8 23.7 1.6 1.5 93.3 3.7

14 452.5 1,375 3.0 3.4 39.2 9.0 20.6 27.6 23.1 3.5 40.9 34.3

15 353.2 992 2.8 4.9 28.6 3.3 14.0 49.1 19.3 5.5 35.3 42.1

16 1818.0 12,789 7.0 9.8 29.4 8.8 22.2 28.3 8.7 2.4 63.3 26.8

17 247.8 1,019 4.1 13.1 39.5 17.8 16.6 13.0 6.0 1.6 65.8 26.7

18 277.0 1,046 3.8 13.7 43.8 3.8 23.7 14.5 39.3 14.6 59.4 14.4

19 819.6 3,121 3.8 12.0 41.1 11.9 30.4 4.0 25.3 16.8 29.3 43.4

20 625.1 1,857 3.0 11.6 34.9 24.1 21.7 7.7 24.0 8.8 0.8 66.5

Land use (%) Domenstic waste water treatment (%)

Area (ha)

Population (person)

Population density (person ha^-1) Watershed

No.

Table 2-4 Co ef fi cie nt o f co rrel ati o n betw ee n o bs e rv e d a n d e sti ma t e d ri ve r di sc h a rg e a s a funct io n of t he prec e di ng pe ri o d of ti me bef ore sa mpl i ng. T he me an pre ci pit at ion dur i ng t he pre ce di ng pe ri o d w as us e d f o r c al c ul ati o n.

99/03 99/06 00/03 00/06 Mean

1day 0.28 0.11 0.03 0.60 0.26

2days 0.03 0.11 0.22 0.83 0.30

3days 0.48 0.11 0.41 0.83 0.46

4days 0.18 0.11 0.41 0.62 0.33

5days 0.36 0.09 0.58 0.54 0.39

6days 0.21 0.09 0.43 0.60 0.33

7days 0.22 0.01 0.44 0.70 0.34

Period of time Measurement month

20

ಀ ᩘ 䛜 0.1䡚0.5 䛰䛳䛯䛾䛻ẚ 䜉䛶䠈㞵 䛾ᙳ 㡪 䜢ཷ 䛡䛶䛔䜛 2000 ᖺ 6 ᭶ 䛾᫬ 䛾┦ 㛵 ಀ ᩘ 䛿 0.5䡚0.8 䛸኱ 䛝 䛟ୖ ᅇ 䛳䛶䛔䛯䚹䛣䛾 ⌮ ⏤ 䛸䛧䛶䠈ᬕ ኳ 䛜⥆ 䛡䜀 ᅵ ተ Ỉ ศ 㔞 䛜 ప ୗ 䛧䠈㝆 㞵 䛾 ᅵ ተ 䛻 䝖 䝷䝑 䝥䛥䜜 䜛 㔞 䛿ከ 䛟 䛺䜚䠈ὶ ฟ ⋡ 䛿ప ୗ 䛩 䜛 䚹 㝆 㞵 㔞 䛜 ከ 䛟 䛺䜜䜀 ὶ ฟ ⋡ 䛿㧗 䛟 䛺䜚䠈ᅵ ተ 䛻䝖 䝷䝑 䝥䛥䜜䛯㔞 䜔 䛭䛾 ௚ 䛾 ὶ ฟ 㜼 ᐖ 䛾 ᙳ 㡪 䛿 ┦ ᑐ

ⓗ 䛻 ᑠ 䛥䛟 䛺䜛 䚹 ᚑ 䛳 䛶䠈 㞵 ኳ ᫬ 䛻 ┦ 㛵 䛜 㧗 䛟 䛺 䛳 䛯 ⤖ ᯝ 䛿 ጇ ᙜ 䛺䜒 䛾 䛸 ⪃ 䛘 䜙䜜 䜛 䚹 䛣䛾஦ 䛛䜙䠈௨ ୗ 䛷⾜ 䛖ὶ 㔞 䛾᥎ ᐃ 䛻 䛿 3 ᪥ ๓ 䜎䛷䛾ඛ ⾜ 㝆 㞵 㔞 䛾ᖹ ᆒ ್ 䜢⏝ 䛔䜛

஦ 䛸䛧䛯䚹䛺䛚䠈1999 ᖺ 䛿ᖹ ᖺ 䛻ẚ 䜉䛶㝆 Ỉ 㔞 䛜 䛛䛺䜚ప 䛛䛳䛯䛯䜑䠈௨ ୗ 䛷䛿ప Ỉ

᫬ 䛾ㄗ ᕪ 䜢ཷ 䛡䛻䛟䛔 2000 ᖺ 䛾䝕䞊䝍䜢䝯䜲䞁䛻ゎ ᯒ 䜢⾜ 䛳䛯䚹

㸦 3 㸧 ᐇ   ὶ 㔞 䛸ண   ὶ 㔞 䛾ẚ ㍑

ᐇ   䛾 Ἑ ᕝ Ỉ ㉁ 䛸 ண   Ỉ ㉁ 䛾 ẚ ㍑ 䜢 ⾜ 䛖 ๓ 䛻 䠈 ὶ 㔞 䛜 ṇ ☜ 䛻 ண   䛥 䜜 䛶 䛔 䛺 䛡 䜜 䜀 ⃰ ᗘ 䛾 ẚ ㍑ 䜢 ⾜ 䛘 䛺 䛔 䛯 䜑 䠈 ᭱ ึ 䛻 ᐇ   ὶ 㔞 䛸 ண   ὶ 㔞 䛾 ẚ ㍑ 䜢 ⾜ 䛳 䛯 䠄Table 2-5䠅 䚹ᐇ   ὶ 㔞 䛿䛚䛚䜘䛭 ᬕ ኳ ᫬ 䛾 䜒䛾䛸⪃ 䛘 䜙䜜䜛䛜 䠈ண   ὶ 㔞 䛿ᖺ 㛫 䛾

⥲ Ỉ 㔞 䜢᪥ 㔞 ᥮ ⟬ 䛧䛯䜒䛾䛷䛒 䜛 䚹䛣䛾Ⅽ 䠈ண   ್ 䛿ᖺ 㛫 ᖹ ᆒ ್ 䜢ồ 䜑 䛶䛔 䜛䛸 ⪃ 䛘 䜙䜜䠈䛒䜛⛬ ᗘ 䛾ㄗ ᕪ 䛿Ꮡ ᅾ 䛩䜛䜒䛾䛸䛧䛶᳨ ウ 䜢⾜ 䛖䚹ᐇ   ್ 䛸ண   ್ 䛾ᕪ 䜢ぢ 䜛䛸 䠈 㞟 Ỉ ᇦ 10䠈15䠈16䠈19 䛾 4 䛴䜢㝖 䛝䜋䜌㼼100%௨ ෆ 䛾ㄗ ᕪ 䛻཰ 䜎䛳䛯䚹㞟 Ỉ ᇦ 10 䛿ᬯ Ὼ ᤼ ฟ ཱྀ 䛾䛩䛠ഃ 䛷䠈ఱ 䜙䛛䛾ᙳ 㡪 䜢ཷ 䛡䛯䛸⪃ 䛘䜙䜜䜛䚹 㞟 Ỉ ᇦ 19䛿2000ᖺ 䛻 䛺 䛳 䛶 ὶ 㔞 䛜 ῶ 䛳 䛶䛔 䜛 䛾 䛷 䠈 ὶ ᇦ 䛾 Ỉ ฼ ⏝ ᙧ ែ 䛜 ᨵ ኚ 䛥䜜 䛯 ྍ ⬟ ᛶ 䛜 ⪃ 䛘 䜙 䜜 䜛䚹㞟 Ỉ ᇦ 10䠈19 䛻 䛴䛔䛶䛿䠈䝃䞁䝥䝹䛾ಙ 㢗 ᛶ 䛜 ஈ 䛧䛔 ஦ 䛛䜙௨ ᚋ 䛾⪃ ᐹ 䛛䜙䛿 㝖 እ 䛩䜛䚹㞟 Ỉ ᇦ 15䠈16䛻䛴䛔䛶䛿 2000ᖺ 3᭶ 䛾್ 䛾䜏䛜኱ 䛝䛟䛿䛪䜜䛶䛔䜛஦ 䛛 䜙 䠈 䛣 䛾 ᫬ 䛾 䝕 䞊 䝍 䛾 䜏 ௨ ᚋ 䛾 ⪃ ᐹ 䛛 䜙 㝖 እ 䛩 䜛 䚹 Ἑ ᕝ ὶ 㔞 䛾 ㄪ ᰝ 䛿 䠈 ㄪ ᰝ ᆅ Ⅼ 䛾 ᙧ ≧ 䜔 ㄪ ᰝ ᫬ 㛫 ➼ 䛾ᵝ 䚻 䛺せ ᅉ 䛻䜘 䛳䛶ᩘ ್ 䛜 䝞 䝷䛴 䛟 ஦ 䛜ከ 䛔䛾䛜 ୍ ⯡ ⓗ 䛷䛒䜛 䛜䠈䛭䛖䛔䛳䛯ㄗ ᕪ 䜢ྵ 䜣䛷䛔䜛஦ 䜢ຍ ࿡ 䛩䜜䜀䠈ẚ ㍑ ⓗ Ⰻ 䛔 ⤖ ᯝ 䛷 䛒䜛䛸䛔䛘䜛 䛰䜝 䛖䚹௨ ୗ 䛷 䛿ὶ 㔞 䛻 䛴䛔䛶䛿 㐺 ṇ 䛺⠊ ᅖ 䛷 ⾲ ⌧ 䛥䜜 䛶䛔䜛 䛸 䛧䛶䠈ᐇ   Ỉ ㉁ 䛸 ண   Ỉ

㉁ 䛾ẚ ㍑ 䜢⾜ 䛖஦ 䛷䠈㈇ Ⲵ 㔞 䛾⟬ ᐃ 䛜ṇ 䛧䛔䛛䛹䛖䛛䛾ホ ౯ 䜢⾜ 䛳䛯䚹