@article{oai:kumadai.repo.nii.ac.jp:00024950,
 author = {Tomiie, Kazuo and Itomitsu, Naotaka and Matsuyama, Kenji and Kakimoto, Ryuji and 柿本, 竜治 and 川越, 保徳 and Kawagoshi, Yasunori and 富家, 和男 and 糸満, 尚貴 and 松山, 賢司 and Kakimoto, Ryuji and 柿本, 竜治 and 川越, 保徳 and Kawagoshi, Yasunori},
 issue = {1},
 journal = {水環境学会誌},
 month = {Jan},
 note = {application/pdf, 論文(Article), 熊本市とその近隣市町村からなる熊本都市域は，1,000 km2を超える面積を有し，100万人市民の飲用水のすべてを地下水で賄う世界的にも珍しい広大な地下水流域であるが，近年，硝酸性窒素（NO3-N）による水質汚染が懸念されている。そこで本研究では，NO3-N汚染の実態と窒素負荷要因の解明を目的に調査研究を行った。本都市域では，NO3-N濃度が4 mg・L-1を超える地下水が多くみられ，10 mg・L-1を超えるものもあった。また，ほとんどの地下水でNO3-N濃度の上昇が認められた。地理情報システム（GIS）を用いた農林業センサスデータ解析から，地下水上流域で家畜排せつ物からの窒素負荷が近年著しく増加していた可能性が示され，窒素安定同位体（δ15N）分析より，主な窒素源は有機態窒素であることが分かった。以上より，本都市域での主な窒素負荷要因は家畜排せつ物や堆肥等の有機態窒素であると結論した。, Kumamoto city and its neighboring municipalities, which is more than 1,000 km2 in area and have almost 1 million people, are considered a mesoscale region. This region is a special area in Japan and in the world because of the fact that all drinking water demand by most of its population is met using only groundwater. However, recently, nitrate-nitrogen (NO3-N) contamination has been a source of concern. The goal of this study is to examine the groundwater contamination by NO3-N in this area and to determine the factors of nitrogen load. NO3-N concentration was higher than 4 mg·L-1 in many wells, it was even higher than 10 mg·L-1 in some wells in upstream areas of groundwater. In addition, most groundwater samples showed an upward trend in NO3-N concentration in recent years. The Geographical Information System (GIS) technique using agricultural census data revealed that nitrogen emission from domestic animal waste significantly increased in the upstream areas of groundwater, which was coincident with the NO3-N contamination of groundwater. The nitrogen stable isotope ratios (δ15N) of NO3-N in groundwater were relatively high (9.6 to 15) in most of the wells, and especially higher (10<) in the upstream areas of groundwater. From these results, domestic animals waste and the application of organic fertilizers were identified by the effective combination of the GIS technique and δ15N analysis as the main contributors to NO3-N contamination., http://www.jstage.jst.go.jp/article/jswe/34/1/34_1/_article/-char/ja/},
 pages = {1--9},
 title = {熊本都市域における地下水中硝酸性窒素濃度の現状と地理情報システムおよび窒素安定同位体分析による窒素負荷要因の解明},
 volume = {34},
 year = {2011},
 yomi = {カキモト, リュウジ and カワゴシ, ヤスノリ and カキモト, リュウジ and カワゴシ, ヤスノリ}
}