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Title
  • ja 富栄養化した停滞性水域の結氷下の水質挙動と気候変動による影響
Alternative
  • WATER QUALITY CHARACTERISTICS OF ICE-COVERED, STAGNANT, EUTROPHIC WATER BODIES AS INFLUENCED BY CLIMATE CHANGE
Creator

杉原, 幸樹

中津川, 誠

Rights
    • © copyright 2013 土木学会
Subject
  • Other eutrophication
  • Other freezing
  • Other ecosystem model
  • Other climate change
  • NDC 517
Description
Other
  • 本研究は結氷下の水質観測やシミュレーションに基づき,結氷下の水質挙動を明らかにし,気候変動による影響を検討した.観測結果から結氷による再曝気の遮断に伴い底層が無酸素化して栄養塩が溶出し,それが解氷まで蓄えられることがわかった.一方,気温上昇により結氷期間が短縮され,蓄えられる栄養塩が減少するが,解氷後に植物プランクトンの増殖が促進され,BODが上昇傾向を示した.これらの実態を反映し,気候変動の影響を検証して将来予測を行うために,結氷を勘案できる水質シミュレーションモデルを構築した.これによる計算結果から気温の上昇により結氷期間が短縮し,春季のBODが増加することが示され,観測結果と一致した.これらの結果より結氷する積雪寒冷地の水域において気温上昇が春季の富栄養化を促進することが示唆された.
Other
  • This study clarifies the water quality characteristics of stagnant, eutrophic water bodies that freeze in winter, based on our surveys and simulations, and examines how climate change may influence those characteristics. The survey found that climate-change-related increases in water temperature were suppressed by ice covering the water area, which also blocked oxygen supply. It was also clarified that the bottom sediment consumed oxygen and turned the water layers anaerobic beginning from the bottom layer, and that nutrient salts eluted from the bottom sediment. The eluted nutrient salts were stored in the water body until the ice melted. Climate change was surveyed as having caused decreases in nutrient salts concentration because of the shortened ice-covered period; however, BOD showed a tendency to increase because of the proliferation of phytoplankton that was promoted by the climate-change-related increase in water temperature in spring. To forecast the water quality by using these findings, particularly the influence of climate change, we constructed a water quality simulation model that incorporates the freezing-over of water bodies. The constructed model shows good temporal and spatial reproducibility and enables water quality to be forecast throughout the year, including during the ice-covered period. The forecasts using the model agree well with the survey results of shortened ice period and climate-change-related increase in the BOD in spring.
Publisher土木学会
Date Created 2019-03-12 , Issued 2013
Languagejpn
NIItypejournal article
VersiontypeVoR
Identifier URI http://hdl.handle.net/10258/00009745
Relation
  • isIdenticalTo DOI https://doi.org/10.2208/jscejhe.69.44
  • isIdenticalTo NAID 130004961419
  • isVersionOf URI https://www.jstage.jst.go.jp/article/jscejhe/69/1/69_44/_pdf/-char/ja
Journal
    • NCID AA12373113
    • ISSN 2185-467X
    • 土木学会論文集B1(水工学) = Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering)
    69(1), 44-59
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Oaidate2020-06-25T06:57:01Z