Research on flow field and rehabilitation of aquatic environment in the Ariake Sea

1）2003年夏季在有明海整个北方进行了大规模的现场观测。得到了在强密度分层条件下的流动和分层结构。（2）观测结果证实，伊沙亚湾口的水流结构取决于潮汐条件（春小潮变化），而岛原半岛沿着海岸的强流则不受潮汐条件的影响。3)有明海四个点的流速有减小的趋势。认为伊沙亚海堤影响了从伊沙亚湾内部到有明海中心的水流结构。4）2004年小潮时对伊沙亚湾进行了潮流和分层的现场观测。结果得到了三维流动结构随时间的变化。5）通过多元回归分析，证实了有明海北方海域的流场是 ...更多信息 深受风场的影响6)对筑后江河口及佐贺县沿岸地区的底质样品进行了粒度和营养盐分析，明确了底质的分布特征。7)建立了与潮汐湿地子模型相配合的Σ坐标三维潮流数值模型。（8）通过对伊沙亚湾口溶解氧和潮流的现场观测，证实了该湾的氧压取决于河流和伊沙亚海堤的淡水入流排放。9)提出了一种利用野外观测数据估计卫星图像透明度分布的算法。10)通过模型试验和数值试验，研究了在有明海域设置的海底粗糙度对潮汐交换的激活作用。用这种方法可以使北方与南方的潮汐交换恢复到伊沙亚海堤修筑前的状态。11)在伊沙亚湾进行的原型实验证实了底糙率引起的上升流。少

1)A large scale in-situ observation project was carried out in the overall northern part of the Ariake Sea in summer, 2003. Flow and stratification structures under a strong stratification of density due to heavy rainfalll were obtained. 2)It is confirmed from results of field observations that flow structure at the mouth of the Isahaya Bay depends on tidal condition (spring-neap variation), but strong flow along shore of the Shimabara Peninsula dose not. 3)Decreasing trend of velocity at four points in the Ariake Sea was confirmed. It is considered that the Isahaya sea-dyke affects flow structure from the inner area of the Isahaya Bay to the center area of the Ariake Sea. 4)In-situ observations of tidal current and stratification in overall area of the Isahaya Bay were carried out at neap tide in 2004. As a result temporal variation of 3-dimensional flow structure was obtained. 5)It was confirmed by multi-regression analysis that a flow field in the northern area of the Ariake Sea is … More deeply affected by a wind field. 6)Characteristics of bottom sediment distribution around river mouth of the Chikugo River and coastal area of Saga Prefecture were clarified by grain size and nutrients analysis for core samples of bottom sediment. 7)The sigma-coordinate 3-D numerical model of tidal current cooperated with tidal wetland sub-model was developed. 8)It was confirmed from results of field observations of dissolved oxygen and tidal current at the mouth of the Isahaya Bay that oxygen depression depends on inflow discharge of fresh water from rivers and the Isahaya sea-dyke. 9)The algorithm to estimate a distribution of transparency from a satellite image was developed by using the dataset of field observations. 10)Model and numerical experiments to investigate activation effect of the Bottom Roughness installed in the Ariake Sea on tidal exchange was carried out. The tidal exchange between the northern area and the southern area can be restored to the original state before constructing the Isahaya sea-dyke by this method. 11)Upwelling current by the Bottom Roughness was confirmed by a prototype experiment in the Isahaya Bay. Less