青森県六ケ所村の使用済み核燃料再処理施設に隣接する汽水湖尾駮沼において,物質挙動を支配する基礎情報である流動場及び海水交換率を明らかにすることを目的に,2020年8月1日~12月10日の期間,沼内の塩分及び流況,淡水流入量・流出量,及び沼-海を結ぶ水道部の海水流入量に関する調査を行った。尾駮沼の表層(水深0.5 m)及び底層(同3.5 m)における塩分の平均はそれぞれ21.1(変動範囲12.2~28.0)及び26.6(同19.7~31.7)psuとなり,海水の約3分の2の塩分が存在した。また,湖心部における平均流速は上下層ともに5 cm s-1以下と緩やかであり,90%以上が低流速(10 cm s-1未満)であった。尾駮沼への淡水流入量,海水流入量及び湖水流出量の平均はそれぞれ1.0×105,4.2×105及び5.9×105 m3 d-1と推定され,淡水流入量と海水流入量の和が概ね湖水流出量であった。これらの結果より,尾駮沼水道部における海水交換率の平均値±SDは0.58±0.15 d-1と推定され,上げ潮時に流入する海水の半分程度は下げ潮時に沼から流出することが示唆された。
{"title":"Geological characteristics influencing dissolved inorganic phosphorus (DIP) concentrations in forested watershed rivers in eastern Hokkaido: A case study of the Lake Nukabira Dam Watershed in the Daisetsuzan National Park","authors":"Toshikazu KIZUKA, Hiroaki SUZUKI, Yoshiki HASEGAWA, Kazuhiro HAMAHARA, Hidetoshi MIKAMI","doi":"10.3739/rikusui.84.37","DOIUrl":"https://doi.org/10.3739/rikusui.84.37","url":null,"abstract":"","PeriodicalId":35602,"journal":{"name":"Japanese Journal of Limnology","volume":"329 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136120323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Memorial to the Deceased Takayuki HANAZATO","authors":"","doi":"10.3739/rikusui.83.89","DOIUrl":"https://doi.org/10.3739/rikusui.83.89","url":null,"abstract":"","PeriodicalId":35602,"journal":{"name":"Japanese Journal of Limnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42659893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}