Project/Area Number |
09650567
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
水工水理学
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Research Institution | HIROSHIMA UNIVERSITY |
Principal Investigator |
WATANABE Akihide Hiroshima University, Department of Engineering, Associate Professor, 工学部, 助教授 (00240474)
|
Co-Investigator(Kenkyū-buntansha) |
HIBINO Tadashi Port and Harbour Research Institute, Senior Research Engineer, 主任研究官 (50263736)
TAKABATAKE Hiroshi Hiroshima University, Department of Engineering, Research Associate, 工学部, 助手 (60294542)
FUKUOKA Shoji Hiroshima University, Department of Engineering, Professor, 工学部, 教授 (30016472)
|
Project Period (FY) |
1997 – 1998
|
Project Status |
Completed (Fiscal Year 1998)
|
Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1998: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1997: ¥2,500,000 (Direct Cost: ¥2,500,000)
|
Keywords | enclosed brackish lake / stratified layers / atmospheric condition / flow field / inner wave / water quality / Field survey / Track Point system / 超音波 / 汽水湖 / Track Point System / 水交換 / 密度躍層 / 潮汐 |
Research Abstract |
Enclosed brackish waters near the river mouse has stratified layers of freash and salty water, so that there are the various problems on the water quality such as low oxygen, salinity water and so on because of complex flow field affected by atmospheric and astronomical phenomena; ex. Stress of wind, change in atmospheric pressure, tidal flows. Recently, measurement devices such as ADCP, DGPS and so on are used for the field survey on flows. However, the measuring of flow fields is difficult because of the large area of lake. In this research, Track point system is developed for surveying the flows in a stratified and enclosed brackish waters. It is one accorstic survey system which follow the 3D coordiate-point of the floating transponder which move with the stratified water. This system has the sufficient accuracy compared with DGPS by using the moving average value of the coordinate-point in time and has the measuring range about 1 km. We apply the this system to survey the flows at Yonago Bay of Nakaumi Lake in Shimane Prefecture. As results, it was revealed that the floating transponder in the stratified water can follow the moving water surround it and its moving speed is same with one measured by ADCP at the same time. Further, it was shown that the moving range of stratified water due to the tidal flows is about a few km and the flow fields in Nakaumi Lake is greatly affected by wind, atmospheric pressure, geometry and so on.
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