Influence of Regional Warming Trend on Water Quality Change in Lake as Agricultural Water Resources

2015 Fiscal Year Final Research Report

• Project/Area Number: 25450364
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Rural environmental engineering/Planning
• Research Institution: Kagoshima University
• Principal Investigator: MOMII KAZURO 鹿児島大学, 農水産獣医学域農学系, 教授 (40136536)
• Co-Investigator(Kenkyū-buntansha): ITO Yuji 鹿児島大学, 農水産獣医学域農学系, 准教授 (60526911)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 湖水循環 / ポテンシャルエネルギー / 乱れエネルギー / 数値解析 / 植物プランクトン / 栄養塩濃度 / 溶存酸素 / 熱環境

Outline of Final Research Achievements

Based on the field observation and numerical simulation, this study focuses on the influence of the regional warming trend on the water quality and circulation of the lake as valuable water resources in the study site. Concerning the lake water circulation, the numerical results show that the potential energy of the lake water becomes smaller than the wind-induced turbulent energy for the vertical mixing in February of 1986, 2011 and 2012 during 1986-2013. The simulation study reveals that the decrease in the potential energy is caused by the temporal hiatus in the air temperature increase since 2000 in comparison with 1977-1999. The results on the water quality suggest that the long-term fluctuations of the lake thermal environment due to the regional climate change favor eutrophication and chlorophyll maxima in the deep layer, but that the drastic changes in water quality like red tide cannot occur due to very low concentration of phosphorous in Lake Ikeda.

Free Research Field

水資源学