著者
飯田 貞夫 江口 旻 志村 聡 大島 徹 Sadao Iida Akira Eguchi Satoshi Shimura Toru Oshima 茨城キリスト教大学 松蔭大学 亜細亜大学 茨城県立水戸飯富養護学校
出版者
茨城キリスト教大学
雑誌
茨城キリスト教大学紀要 2 社会・自然科学 (ISSN:13426370)
巻号頁・発行日
no.40, pp.185-204, 2006

(1)本流のpHは,7.0~7.4の間にある。左岸支流のpHは3.4~7.6の問にあり,松川,荒川,須川など,上流に火山地帯がある河川と温泉水が流入する河川では酸性を示す。右岸支流のpHは,7.0~8.4の間にある。花崗岩,石灰岩地域を流下するため,アルカリ性を示す。(2)本流のDOは,10.2~11.4ppmの間にある。左岸支流は,8.9~13.6ppm。DOは扇状地の支流で12.2~13.6ppmと値が高い。右岸支流のDOは,8.7ppmと左岸より少ない。(3)本流の透視度は,7.6~27cmと低い値を示す。左岸の透視度は,荒川32cm,濁川40cm,摺上川44.5cmで低い値を示すが,他の支流は50cm以上である。右岸の透視度は,谷底平野や水田地帯を流下する胡桃川22cm,東根川24cm,境川41cmで低い。(4)本流の電気伝導度は,61.7~158μ&mho;/cmで変化する。左岸支流の電気伝導度は59.6~891.2μ&mho;/cmで変化し,温泉水が流入する小川891.2μ&mho;/cm,須川361μ&mho;/cm,荒川218μ&mho;/cmで高い。右岸支流の電気伝導度は,117~363μ&mho;/cmで,入川で363μ&mho;/cmと高く,谷底平野や水田地帯で高くなっている。(5)本流のCl^-の含有量は,22~38ppmの間にある。左岸支流のCl^-の含有量は,6~36ppmである。温泉水が流入する荒川,須川,松川で含有量が多い。荒川で36ppm,須川で32ppm,小川で28ppmである。右岸支流のCl^-の含有量は,4~86ppmである。入川で特に高い値(86ppm)を示しているが,原因は明らかではない。(6)本流のNa^+の含有量は,3.3~9.6ppmである。左岸支流の含有量は,0.3~28ppmで,水原川で28ppmと多くなる。右岸支流の含有量は1~36.6ppmの問にある。特に入川No.21入川橋で36.6ppmと最高値を示し,EC (891μ&mho;/cm)やCl^- (86ppm)も高い数値を示している。(7)本流のCa^<2+>の含有量は,2.5~19ppmの間で変化している。左岸支流のCa^<2+>の含有量は0.6~6.2ppmで,含有量は少ない。右岸支流のCa^<2+>の含有量は,3.7~22.5ppmと比較的多く,花崗岩,石灰岩地帯を流下する境川No.28飯野で22.5ppmと最高値を示している。(8)本流のMg^<2+>の含有量は,1.8~3.2ppmの間で変化している。左岸支流は,0.8~8ppmであり,荒川や須川など,火山地帯の河川や温泉水の流入する河川で含有量が比較的多い。右岸支流は左岸より多く,2~6.6ppmの間で変化する。(9)本流のNH_<4->Nは,0.12~0.25ppmである。左岸支流のNH_<4->Nは,0.1~0.47ppmで,反田川で0.47ppm,松川で0.25ppmと高い値を示した。右岸支流のNH_<4->Nは,0.12~0.43ppmで,東根川で0.43ppm,岡代橋より3km上流のNo.26根小屋橋で0.32ppmと含有量が多くなる。(10)本流のPO^<3->_4の値は,0.02~0.12ppmの間で変化する。左岸支流のPO^<3->_4は,0.001~0.13ppmで変化し,油井川で0.13ppmを示している。右岸側支流のPO^<3->_4は,0.12~0.43ppmで変化している。(11)左岸支流のCl^-の負荷量は,5.6~241.9g/secで変化する。須川241.9g/sec,荒川205.9g/secで値が高く,松川159.4g/secも高い値を示している。松川,須川,荒川は,いずれも上流に温泉がある。右岸支流のCl^-の負荷量は,1.6~93.9g/secで,木幡川で93.9g/secとなった。(12)左岸支流のNa^+の負荷量は,0.7~98.03g/secである。松川で98.03g/sec,須川で65g/sec,水原川で57.9g/sec,摺上川で56.3g/secで高い値を示す。右岸支流のNa^+の負荷量は,0.78~23.5g/secである。木幡川23.5g/sec,東根川18.9g/secと高い値を示した。(13)左岸支流のCa^<2+>の負荷量は,1~35.4g/secである。荒川で35.4g/secを示した。右岸支流のCa^<2+>の負荷量は,1.2~32.6g/secで,木幡川で32.6g/secである。(14)左岸支流Mg^<2+>の負荷量は,0.14~72.0g/secである。荒川66.7g/sec,須川60.5g/secで高い値を示した。右岸支流のMg^<2+>の負荷量は,0.4~9.6g/secで,左岸側に比べて負荷量の少ない地点が多い。(15)左岸のNH_<4->Nの負荷量は,0.0039~0.13g/sec。荒川1.27g/sec,須川1.02g/sec,荒川1.02g/sec,摺上川1.05g/secなど,温泉水が流入する河川で負荷量が多い。右岸の負荷量は,0.001~0.063g/secで変化している。We have conducted an investigation into the tributaries flowing into the Abukuma river. Our findings can be summarized as follows. (1) In the main stream of the Abukuma, the pH value is 7.0~7.4. In the tributaries of the left bank, it is 3.4~7.6. The Matsukawa, the Arakawa and the Sukawa show the acid reactions because of the inflows of hot spring waters. It is 7.0~8.4 in the branches of the right bank. They are alkalized because they run through the granitic and the limestone districts. (2) DO of the mainstream is 10.2~11.4ppm. In the tributaries of the left bank, it is 8.9~13.6ppm. DO of the branches of the right bank show 8.7ppm. (3) The transparency of the mainstream is 7.6~27cm. As for the tributaries of the left bank, it is 32cm (the Arakawa), 40cm (the Nigori river), and 44.5cm (the Suriage river). The other branches show more than 50cm. In the branches of the right bank, it is 22cm (the Kurumi river), 24cm (the Higashine river), and 41cm (the Sakai river). (4) The electric conductivity of the mainstream is 61.7~158μ&mho;/cm. The tributaries of the left bank show 59.6~891.2μ&mho;/cm. The high values are found in the Ogawa (891.2μ&mho;/cm), the Sugawa (361μ&mho;/cm), the Arakawa (218μμ&mho;/cm). They are fed by the thermal spring waters. In the branches of the right bank, it is 117~363μ&mho;/cm. The high value is observed in the Irilawa (363μ&mho;/cm) which runs through valleys and paddy lands. (5) In the mainstream, the content of Cl^- is 22~38ppm. In the tributary streams of hte left bank, it is 6~36ppm. The high values are seen in the Arakawa (36ppm), the Sugawa (32ppm), and the Ogawa (28ppm) into which the hot spring waters flow. In the branches of the right bank, it is 4~86ppm. That of the Irikawa shows especially high value (86ppm), but the cause is unknown. (6) In the mainstream, the content of Na^+ is 3.3~9.6ppm. In the tributary streams of the left bank, it is 0.3~28ppm. The highest value (28ppm) is found in the Kihara river. In the tributary streams of the right bank, it is 1~36.6ppm. At Irikawa (No.21) and the Irikawa bridge, the highest values are observed, and there the contents of EC (891μ&mho;/cm) and Cl^- (86ppm) are also high. (7) In the main stream, the content of Ca^<2+> is 2.5~19ppm. In the tributaries of the left bank, it is 0.6~6.2ppm. In the tributary streams of the right bank, it is relatively high value, 3.7~22.5ppm. The highest value (22.5ppm) is observed in the Sakai river (No.28) by the side of lino (No.28) which runs through the granitic and the limestone area. (8) In the mainstream, the content of Mg^<2+> is 1.8~3.2ppm. In the tributaries of the left bank, it is 0.8~8ppm. The high values are found in the Arakawa and the Sugawa into which hot spring waters flow. In the branches of the right bank, it is 2~6.6ppm. (9) In the mainstream, the NH_<4->N content is 0.12~0.25ppm. In the branches of the left bank, it is 0.1~0.47ppm. The high values are observed in the Handa river (0.47ppm) and the Matsukawa river (0.25ppm). In the branches of the right bank, it is 0.12~0.43ppm. The high values are found in the Higashine river (0.43ppm) and at the point 3 kilometers upstream from the Okashiro bridge (0.32ppm). (10) In the mainstream, the PO^<3->_4 content is 0.02~0.12ppm. In the tributaries of the left bank, it is 0.001~0.13ppm. In the Aburai river, it is 0.13ppm. In the branches of the right bank, it is 0.12~0.43ppm. (11) In the branches of the left bank, the load of Cl^- is 5.6~241.9g/sec. The high figures are found in the Sukawa (241.9g/sec), the Arakawa (205.9g/sec) and the Matsukawa (159.4g/sec) which have spas in their upper reaches. In the tributaries of the left bank, the load of Cl^- is 1.6~93.9g/sec. The highest figure is found in the Kibata river. (12) The load of Na^+ is 0.7~98.03g/sec in the tributaries of the left bank. The high value is seen in the Matsukawa (98.03g/sec), the Sugawa (65g/sec) the Mizuhara river (57.9g/sec) and the Suriage river (56.3g/sec). In the branches of the right bank, it is 0.78~33.5g/sec. The high value can be found in the Kibata river (23.5g/sec) and the Higashine river (18.9g/sec). (13) In the tributaries of the left bank, the load of Ca^<2+> is 1~35.4g/sec. The highest value is found in the Arakawa. In the branches of the right bank, it is 1.2~32.6g/sec. The highest value is observed in the Kibata river. (14) In the tributaries of the left bank, the load of Mg^<2+> is 0.14~72.0g/sec. The high values are observed in the Arakawa (66.7g/sec) and the Sugawa (60.5g/sec). In the branches of hte right bank, ti is 0.4~9.6g/see. The branches of the right bank show lower values than those of the left bank. (15) In the branches of the left bank, the load of NH_<4->N is 0.0039~0.13g/sec. The high values are found in the Arakawa (27g/sec), the Sugawa (1.02g/sec) and the Sugawa (1.02g/sec). They are fed by hot spring waters. In the tributaries of the right bank, it is 0.001-0.063g/sec.