Study on re-suspension, transport, and settlement processes of particulate matter in an estuarine environment under multi-scale effects

环东京湾运河网络被认为是日本最复杂的网络系统之一，本研究的目的是通过考虑流场的多尺度效应来阐明质量传输的机制。在分析中，采用了三维数值计算和垂直积分的二维数值计算模型，以揭示分层流场中的能量传递和质量传递。在现场观测中，对东大岛、千叶东洋和东京港等几个站点的盐度和溶解氧进行了连续几个月的测量，每隔10min测量一次盐度和溶解氧，结果表明千叶东洋的水质对东京港和东京都的水质有影响。另一方面，关于溶解氧的野外观测表明，由于层结效应的不连续性，渠道内的缺氧与湾头的缺氧没有任何关系。因此，在分析多尺度分层流场中的传质问题时，有必要对分层结构进行评价，以明确影响区域。

This study aims to clarify the mechanisms of mass transport in a network of canal around Tokyo Bay by taking into account multi-scale effect on flow field, which is considered one of the most complicated network systems in Japan. In the analysis, three-dimensional numerical computation and vertically integrated two-dimensional numerical computation models were applied in order to reveal energy transfer and mass transport in a stratified flow field. In the field observation, salinity and dissolved oxygen were measured with the interval of 10min for a few months at several stations, such as Higashi-Ogijima, Chiba-Tohyo and Tokyo Port, which reveals that water quality in Chiba-Tohyo influences in Tokyo Port and Higashi-Ogijima. On the other hand, field observation regarding dissolved oxygen demonstrated that anoxia in canal does not have any relation with that in the bay head because of the discontinuity of stratification effect. Therefore, it is found to be necessary to evaluate the structure of stratification in order to clarify the influential region when you analyze mass transport in multi-scale stratified flow field.