2005 Fiscal Year Final Research Report Summary
Design method of environment in rivers with self-repairing functions in habitat
| Project/Area Number |
16360264
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Civil and environmental engineering
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
KUSUDA Tetsuya Kyushu University, Faculty of Engineering, Professor, 大学院・工学研究院, 教授 (50037967)
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| Co-Investigator(Kenkyū-buntansha) |
KUBA Takahiro Kyushu University, Faculty of Engineering, Associate Professor, 大学院・工学研究院, 助教授 (60284527)
OHISHI Kyoko Kyushu University, Faculty of Engineering, Research Associate, 大学院・工学研究院, 助手 (20110835)
YAMANISHI Hiroyuki Saga University, Institute of Lowland Technology, Associate Professor, 低平地研究センター, 助教授 (20240062)
MATSUI Seiichi Kyushu University, Faculty of Agriculture, Professor, 大学院・農学研究院, 教授 (60038297)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Watershed / Habitat / Preservation / Design of habitat / HEP / Deiratonotus japonicus / Gokase River / Kita river |
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| Research Abstract |
For the preservation of Deiratonotus japonicus, a small crab, which is a kind of less data species by Ministry of Environment, Japan, we conducted field surveys on the existing number and preference of it in the Kita River in the Gokase River System, Miyazaki, Japan. They had been decreasing from 3.5 millions since 2002 and hit the lowest, 50 thousands in 2005, and then slightly increases as of yet;. This seems due to natural fluctuation, but predation.
We utilized the Habitat Evaluation Procedure for investigating their preference and characteristics on behavior in the river. Their adults prefer rather large pebbles with 10-15mm in diameter and high salinity. On the other hand, their zoeas do low salinity. No tendency was found on light intensity.
Their bleeding was tried and succeeded in it from egg to zoea and sometimes to magalopa with S-type copepoda Its zoeas prefer high salinity, on the other hand its adults do opposite. In order to bleed them stably until megalopa, we need further work to choose baits.
We also tried to identify the species of crustacean by use of a gene technique. Contamination by shell caused severe problems on analysis, so that we must consider new techniques to avoid contamination.
A new model to simulate flow and salinity transport was developed. By using it, the movement of its zoeas were analyzed. As a result of it, its zoeas were estimated that they exist around the top of the salt wedge based on their preference. Because river morphology is a key in the relationship between the location of the top of the salt wedge and the size of deposits, we have to pay attention on the design of the river.
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