日本語フィールド
著者:山西博幸,土持旬平,黒木圭介題名:干潟環境改善工作物としての粗朶搦工の利用に関する研究発表情報:環境工学研究論文集 巻: 47 ページ: 207-213キーワード:wake, mud flat, cohesive sediment transport, benthos, simulation概要:抄録:本研究は,かつて干拓技術として用いられてきた粗朶搦工を応用した工作物を現場干潟域に設置し,微細粒土砂の捕捉とともにアゲマキを含む浮遊幼生の着床地あるいは底生生物の生息場創出の可能性について,現地での実証実験と数値計算により検討した.長期にわたる粗朶搦工周辺部の観測結果より,経年的な干潟域での泥の堆積速度を明らかにするとともに,数値計算結果は現地底泥堆積分布の結果とほぼ一致した.また,粗朶搦工撤去前後の底質環境変化を,粒度分布に基づくエントロピー量にて評価した.さらに,直立構造物背部の後流域への物質集積能を主流域への連行係数を使って評価し,相対高さ(D/h)の大きくなる下げ潮時に水中物質の集積能が高まることを示した.英語フィールド
Author:Hiroyuki YAMANISHI, Junpei TSUCHIMOCHI and Keisuke KUROGITitle:Study on the Effective Use of the Sodagarami for Tidal Flat EnvironmentsAnnouncement information: Vol: 47 Page: 207-213Keyword:wake, mud flat, cohesive sediment transport, benthos, simulationAn abstract:The ancient reclamation technology of structure, Sodagarami, which is enclosed by bundled twigs in a coastal area was applied to improve the mud flat environments. The structure has an acceleration effect of the sedimentation of suspended matters, larvae and plankton in waters into the enclosed area. In this study, the cohesive sediment transport around the Sodagarami structure in the mud flat of the Ariake sea were measured for a long term. The hydrodynamic characteristics and prediction of suspended sediment transport were studied using a numerical model. As a result, it was revealed that the Sodagarami method is useful to make the sedimentation of suspended matters accelerate. Also, the entrainment in a wake area in back of the vertical structure showed that the growing relative height (D/h) makes the sedimentation increase. In addition, the change of mud flat environment was estimated by the entropy method for grain size distribution.