An impact assessment of surrounding river watersheds against a brackish lake for improving its water quality environment

• Project/Area Number: 24780234
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Irrigation, drainage and rural engineering/Rural planning
• Research Institution: Shimane University
• Principal Investigator: SOMURA HIROAKI 島根大学, 生物資源科学部, 准教授 (90403443)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2013: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2012: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 河川水環境 / 汽水湖流域 / 水・物質循環 / 小河川流域 / 水環境 / 水文学

Outline of Final Research Achievements

Water quality in a brackish lake has been tried to improve by emission control of pollutant loads to the lake and rivers through putting an adequate sewage system in place and development of laws, though water quality in the lake does not been improved well as we expected. Thus, the Lake Abashiri basin containing seven river watersheds was chosen as a target area and conducted a field research and water quality analysis from April to December in 2013 and 2014. As results, it was grasped a relationship between water quality and landuse ratio among the watersheds. As well, it was understood that the Abashiri River had the biggest impact for water environment in the Lake Abashiri because of its watershed size. Moreover, it was presumed that an impact of the surrounding small watersheds, where contained higher agricultural and residential area, against water quality in the lake might not be negligible because concentrations of water quality were higher than the forest-dominant watersheds.

Research Products

• [Journal Article] Impact of suspended sediment and nutrient loading from land uses against water quality in the Hii River basin, Japan (2012)
  • Author(s): H. Somura, I. Takeda, J.G. Arnold, Y. Mori, J. Jeong, N. Kannan, D. Hoffman
  • Journal Title: Journal of Hydrology Volume: 450 Pages: 25-35
  • DOI: 10.1016/j.jhydrol.2012.05.032
  • Peer Reviewed
• [Presentation] 網走湖周辺河川の水質挙動 (2014)
  • Author(s): 宗村 広昭
  • Organizer: 汽水域研究会網走大会
  • Place of Presentation: 網走市（東京農業大学生物産業学部）
  • Year and Date: 2014-10-04 – 2014-10-05
• [Presentation] Application of SWAT to Lake Shinji watershed for estimating nutrient loadings from surrounding river basins (2014)
  • Author(s): Hiroaki SOMURA
  • Organizer: 2014 International SWAT Conference
  • Place of Presentation: Recife (Brazil)
  • Year and Date: 2014-07-28 – 2014-08-01
• [Presentation] Evaluation of small watersheds inflowing Lake Shinji against the water environment (2013)
  • Author(s): Hiroaki Somura, Yasumichi Yone, Yasushi Mori, Erina Takahashi
  • Organizer: 2013 International SWAT Conference
  • Place of Presentation: Toulouse, Paul Sabatier University
• [Presentation] Estimation of nutrient loadings from a river basin to a downstream lake (2013)
  • Author(s): Hiroaki SOMURA
  • Organizer: Korea AG-BMP Forum The 4th International Conference
  • Place of Presentation: Jeonju, Jeonbuk Provincial Government Complex
  • Invited