Influences of Takisato dam operation on physical environment and aquatic animals in downstream

• SAGAWA Shiro

  Docon Co., Ltd., Environmental Assessment Dept.

• NAKAMORI Touru

  Hokkaido Biogeography Co., Ltd.

• AKIBA Kenji

  Wildlife Research Institute Co., Ltd.

• CHOU Yuhei

  Wildlife Research Institute Co., Ltd.

• KONDOU Satoshi

  Hokkaido Development Bureau Ishikari-river Development and Construction Departments

• WATANABE Masatoshi

  Hokkaido Development Bureau Ishikari-river Development and Construction Departments

Bibliographic Information

Other Title

• 滝里ダム運用が下流河川の物理環境および水生生物に与える影響
• タキサト ダム ウンヨウ ガ カリュウ カセン ノ ブツリ カンキョウ オヨビ スイセイ セイブツ ニ アタエル エイキョウ

Abstract

The effects of dam operations on river environment variables (water depth, current velocity, emergent plants, substrate composition, and channel morphology) and aquatic animals (fish and benthic macroinvertebrates) were examined over a four-year period using the BACI (Before, After, Control, Impact) design, before (1998) and after (1999-2001) regulation, at control (upstream) and impact (downstream) sites. The Takisato Dam is a 50-m vertical-face by 445-m-wide dam in the Sorachi River, Hokkaido, Japan. While there was a large fluctuation (20-80 m³/sec) in the diel discharge before dam operation, dam closure resulted in a low, uniform discharge (9 m³/sec) in the downstream reach, which resulted in low current velocities (from 0.87 m/sec to 0.17-0.42 m/sec) and affected sediment deposition, bar occurrence, pool-riffle sequence, spreading 0 m/sec shore area (0.7 to 21.5%), and emergent plant growth (length of area: 80.0 m to 243.1 m). These changes in the regulated downstream affected the ninespine stickleback (Pungitius pungitius), which became more abundant downstream (cumulative number for four seasons: 147 to 794 individuals), whereas the numbers of Siberian stone loach (Noemacheilus barbatulustoni) did not differ significantly between the periods before and after dam operation. The change in stickleback abundance was related to the establishment of emergent plants and spread of the slow shore area. The macroinvertebrate communities in the control reach upstream from the Takisato Dam remained taxonomically diverse during the study period, while the regulated reach downstream from the dam showed low diversity. However, the effects of the dam on macroinvertebrates differed among the study units (riffle, thalweg, shore). The conservation of taxonomic diversity in the downstream riffles might be due to maintenance of the area of this flow regime, due to the reduced flow width with the low water discharge and the occurrence of bars.

Journal

• Ecology and Civil Engineering

  Ecology and Civil Engineering 7 (1), 65-80, 2004

  Ecology and Civil Engineering Society

Keywords

• BACI design
• dam impact
• macroinvertebrate
• ninespine stickleback
• regulated downstream

Details

• CRID: 1390282679449787776
• NII Article ID: 10021978737
• NII Article ID: 10021976921
• NII Book ID: AA11528360
• DOI: 10.3825/ece.7.65
• ISSN: 18825974
• ISSN: 13443755
• ISSN: http://id.crossref.org/issn/13443755
• NDL BIB ID: 7088356
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7088356
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed