日本地球惑星科学連合2019年大会

講演情報

[J] 口頭発表

セッション記号 A (大気水圏科学) » A-CG 大気海洋・環境科学複合領域・一般

[A-CG40] 沿岸海洋生態系─1.水循環と陸海相互作用

2019年5月28日(火) 10:45 〜 12:15 102 (1F)

コンビーナ:藤井 賢彦(北海道大学大学院地球環境科学研究院)、山田 誠(龍谷大学経済学部)、小路 淳(東京大学大気海洋研究所)、杉本 亮(福井県立大学海洋生物資源学部)、座長:藤井 賢彦山田 誠

10:45 〜 11:00

[ACG40-06] 化学成分と同位体比からみる気候変化に伴う30年間の富山5大河川および海底湧水の栄養塩供給量の変化

*片境 紗希1張 勁2野嶋 航太3 (1.富山大学理工学教育部、2.富山大学理工学研究部、3.富山大学)

キーワード:気候変化、栄養塩、河川水、海底湧水

In Toyama prefecture, 10 billion tons of river and submarine groundwater discharge annually flows in to Toyama Bay containing nutrients (Hatta et al., 2005) . Urasawa et al. (2016) shows that 20-40% of nitrate originated on land contributes to the coastal ecosystems. So it is important to evaluate the state of nutrient transport of from the land to the coastal area. However, global warming has caused an increase in rainfall and a decrease in snowfall in Hokuriku area and it is possible that the states of water and material fluxes has changed over the past years. The aim of this study is to clarify the change of nutrient fluxes via river and submarine groundwater discharge into the coastal area, analyzing hydrogen and oxygen stable isotopes as well as chemical composition.
Results of my analysis, should be, data in my study show that the stable isotopes decreased due to increasing rainfall and decreasing snowfall for three decades. Nitrate and phosphate fluxes are shown to have dramatically decreased as forest and paddy field decreased and the water treatment facilities increased over the years.
These results suggest that nutrient fluxes from the land to coastal zone in this region may continue to decrease due to ongoing climate change and the impact of human activities.