PRE-INVESTIGATIONS FOR WATER QUALITY IMPROVEMENT IN OSAKA-NANKO SAKISHIMA CANAL

• SHINKAI Rie

  大阪市立大学大学院 工学研究科

• YAMOCHI Susumu

  大阪市立大学大学院 工学研究科

Bibliographic Information

Other Title

• 大阪南港咲洲運河の水質改善のための事前調査

Abstract

Field surveys were conducted in Osaka-Nanko Sakishima Canal from May to October 2006, to clarify the water quality and causative organisms of the deteriorated scenery. Steady increase of pH was observed with decreasing salinity at the inner part of the canal due to the inflow of rainwater and/or underground water. Concentrations of dissolved oxygen were high in the bottom water of the canal compared with the surface one in May 2006. This phenomena result from the active photosynthesis of a green alga, Chaetomorpha sp. on the bottom sediment. Nutrient concentrations in the bottom water changed from 0.2 to 1.0mg/L for total nitrogen and from 25 to 50μg/L for total phosphorus in June, July, and September 2006. A marked decline in nutrient concentration was observed below 3m in depth near a sluice gate of the canal. The facts obtained from the present investigations suggest that putting lower the water level in the canal, setting lower the vertical level of the sluice gate, together with enhancement of water exchange are effective for the improvement of water quality and for the depression of algal blooms.

Journal

• PROCEEDINGS OF CIVIL ENGINEERING IN THE OCEAN

  PROCEEDINGS OF CIVIL ENGINEERING IN THE OCEAN 23 715-719, 2007

  Japan Society of Civil Engineers

Keywords

• Osaka-Nanko Sakishima canal
• bloom of Chaetomorpha
• water quality

Details

• CRID: 1390001205205483264
• NII Article ID: 130003950693
• DOI: 10.2208/prooe.23.715
• ISSN: 18848265
• ISSN: 09127348
• Text Lang: ja
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed