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ID 117860
Title Alternative
FIELD SURVEYS OF EFFECTS OF THE MAINTENANCE FLOW DISCHRAGE CHANGE ON RIVER ENVIRONMENT IN THE OHYAMA RIVER
Author
Yano, Shinichiro
Saito, Masanori
Iseri, Yasushi
Simatani, Yukihiro
Ogata, Takeshi
Yamazaki, Masatoshi
Seino, Satoko
Keywords
maintenance flow discharge
hydraulic condition
attached algae
ayu
stable isotope ratio
Content Type
Journal Article
Description
The maintenance flow discharge of the Ohyama River, which is located in the upper Chikugo River, had been restricted to 1.5m3/s by a hydroelectric dam. To improve the river environment, the river administrator has changed the maintenance flow discharge to 4.5m3/s in summer and to 1.8m3/s in winter. In this study, we aim at proposing an optimal control of the maintenance flow discharge for the river environment. Firstly, we carried out field surveys before and after reducing the river discharge in order to figure out effects on hydraulic conditions and attached algae. The results of the surveys show that hydraulic conditions become worse for ayu (plecoglossus altivelis) and attached algae. Also, there is a tendency to stagnate at the pool when the maintenance flow discharge decreases. Secondly, because it was reported that the length of ayu became larger than before changing the maintenance flow discharge, we attempted to analyze carbon and nitrogen stable isotope ratio of ayu and attached algae. We confirmed an obvious difference in food web structure between natural and cultured ayu.
Journal Title
Advances in River Engineering
ISSN
24366714
Publisher
土木学会
Volume
12
Start Page
443
End Page
448
Published Date
2006-06
Rights
© 2006 社団法人 土木学会
EDB ID
URL ( Publisher's Version )
FullText File
language
jpn
TextVersion
Publisher
departments
Science and Technology