2006 Fiscal Year Final Research Report Summary
Study on the formation of mudflat and habitat of benthos due to mud transport in shallow water area
| Project/Area Number |
16360266
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Civil and environmental engineering
|
|---|
| Research Institution | Saga University |
|---|
Principal Investigator |
YAMANISHI Hiroyuki Saga University, Institute of Lowland Technology, Associate Professor, 低平地研究センター, 助教授 (20240062)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
ARAKI Hiroyuki Saga University, Institute of Lowland Technology, Professor, 低平地研究センター, 教授 (70117315)
HINO Takenori Saga University, Institute of Lowland Technology, Lecture, 低平地研究センター, 講師 (20295033)
OHISHI Kyoko Kyushu University, Graduated School of Engineering, Associate Research, 大学院・工学研究院, 助手 (20110835)
TOKUNAGA Takahisa Saga University, Institute of Lowland Technology, Lecture, 低平地研究センター, 講師 (50404009)
|
|---|
| Project Period (FY) |
2004 – 2006
|
| Keywords | The Ariake Sea / Mud / Suspended Solids / Anoxic water / Erosion / Settling flux / Preference curve / Sinonovacula Constrica |
|---|
| Research Abstract |
In this study, water quality in a tidal flat is measured using an automatic ascending-descending instrument that collects hydraulic data and water quality data at various depths over a long period. Analysis of the data, focusing on suspended solids, reveals the variations and distribution of suspended solids in different tidal periods. Information regarding the fluctuation in various physical characteristics of tidal flats was successfully extracted from the obtained measurements. Some of the characteristics of sediment transport over mud flats under the variations of water level were also clarified. This research also attempts to consider that the movement of SS and nutrients, and thus their characteristics and the influence of erosion to water quality are investigated. As a result, it can be said that T-N and T-P are much dependent on the behaviors of mud erosion. They contribute a great effect to the water quality, while DIN and DIP may not be affected clearly by the mud erosion in this limited survey. In addition, parts of nutrients leached in the water from eroded matters were adsorbed to suspended matters again.
Behaviors of suspended matters on the mud flat were investigated by using the sediment-traps and observation towers. Results obtained from the analysis of the amounts of sedimentation and nutrients reveal the characteristics of settling matters in the mud flat. The settling flux observed in the sediment-tarps almost coincided with the net settling flux obtained from a theoretical calculation. The amount of sedimentation to the mud flat was also estimated based upon the settling flux measured in this study. It is shown that the fine cohesive sediment transport in the area was demonstrated through examining the observed data in three towers.
The preference factors of Sinonovacula constrica were extracted by some experiments. As the results, habitat of Sinonovacula constrica was estimated on the base of composite suitability index.
|
Research Products
(4 results)
