Grant-in-Aid for Scientific Research (B)
|Research Institution||KUMAMOTO UNIVERSITY|
TAKIKAWA Kiyoshi Kumamoto University Dept.of Civil and Environmental Eng.Professor, 工学部, 教授 (80040450)
TABUCHI Yoshinobu Kumamoto University Dept.of Civil and Environmental Eng.Lecture, 工学部, 講師 (40037966)
原田 浩幸 熊本大学, 工学部, 助教授 (20222234)
OHMOTO Terunori Kumamoto University Dept.of Civil and Environmental Eng.Associate Professor, 工学部, 助教授 (30150494)
FURUKAWA Kenji Kumamoto University Dept.of Civil and Environmental Eng.Professor, 工学部, 教授 (60029296)
下津 昌司 熊本大学, 工学部, 教授 (20040371)
YAMADA Fumihiko Kumamoto University Dept.of Civil and Environmental Eng.Research Associate, 工学部, 助手 (60264280)
HARADA Hiroyuki Kumamoto University Dept.of Civil and Environmental Eng.Associate Professor (02022234)
|Project Fiscal Year
1996 – 1997
Completed(Fiscal Year 1997)
|Budget Amount *help
¥7,200,000 (Direct Cost : ¥7,200,000)
Fiscal Year 1997 : ¥1,700,000 (Direct Cost : ¥1,700,000)
Fiscal Year 1996 : ¥5,500,000 (Direct Cost : ¥5,500,000)
|Keywords||Environment of Ariake Sea / Environment of Estuary / Effects of River Inflow-Load / Tidal Flat / Denitrification of Tidal Flat / Tidal Current / Air-Born Sea-Salt / Suspended Sediment / 有明海の環境 / 河口域の環境 / 陸水流入 / 干潟 / 干潟の浄化機能 / 閉鎖性海域 / 潮流解析 / 飛来塩分 / 有明海環境 / 干潟の浄化 / 物質の拡散 / 潮流 / 千潟環境 / 環境評価 / 水質浄化能力 / 河口域の流況 / 低沼の巻き上げ沈降|
(1)Numerical analysis of tidal flows and ocean waves were performed for all of Ariake-sea and the both estuary of Sirakawa and Midorikawa rivers. Velocity field characteristics and concentration distributions of suspended solids in those areas were evaluated as a function of tidal levels and river inflow rates. Also, numerical methods for analyzing the form of tidelands and their gullies were developed.
(2)Long term (1924-1990) variation of the tidal flat topography measured by Kumamoto prefecture was considered. In addition, tidal flow and concentration of suspended solids were measured over the tidal flat, which vertical characteristics were discussed.
(3)The Pollutant levels of sediments in the estuaries of Shirakawa and Midorikawa rivers were discussed through the ecological survey results of benthos.
(4)The current study presents the results of chemical analyzes of the potential denitrification and nitrification rates, COD,H_2S in samples collect from 30 study plots located in a grid
(200m*200m) in Ariake-sea. Four sampling points located at different distance and Different depth, near estuary-far estuary, from Midorikawa river, were selected in order to investigation the water quality in Ariake coastal.
(5)The in-vitro effect of Nereis Divesicolor has studied in PVC tubes filled with a coastal marine sediment defaunated by sieving. The aim of this experiment was to determine the effect of sediment defaunation of denitrification.
(6)Field measurements of the space distribution of air-born sea-salt were carried out at the Yokosima reclamation by the drainage field in Tamana county. Numerical models that take into account fall velocities of sea-salt particles and sea-salt concentration diffusion due to rainfall effects were developed. Distribution characteristics of the air-born sea-salt as effected by meteorological conditions were also investigated. Furthermore, the investigation of the perceptions and awareness about environmental factors to inhabitants living in coastal area were performed by using a questionnaire survey.