Analysis on Tidal Transport between Stratified Flow and Sediment Erosion in River and Sallow Water

内陆水域水质优化管理的目的是在潮汐输运模型分析研究的基础上寻求水力技术。该模型考虑了起动水流与河道及浅水底沙侵蚀的关系。(1)在宽20 cm、高30 cm、长8 m的感潮水槽中，对感潮河道非恒定流的物理过程进行了实验模拟。这一结果表明，流速剖面是由两个方向的水流和速度大小的组合所给出的许多图案组成的。在后续的研究中，引入了许多关于河口至排水闸段地层的新知识。(2)本文分别评述了双层底坎过流、收缩过流以及两者结合的内部水力学理论和实验研究的新进展。从最小流、特征流和泛函流三个方面对临界流的评价方法进行了总结，并讨论了临界流对流动分析的发展能力。(3)感潮河道中的均匀异重流在感潮期既有水力特性，又有由于内表面的快速过渡而引起的不稳定性问题。本文报告了一个分析考虑的结果，依赖于现场数据和测量确认在日治河。(4)通过对北田湾养殖场内及养殖场下污染水体和沉积物行为的连续实地研究，阐明了缺氧水体在该环境下的行为特征。

The aim for the optimum management of water quality in inland water is to seek for hydraulic techniques besed on analytical researches by tidal transport model. The model takes account of the relation between startified flow and sediment erosion in channel and shallow water bottom.(1) The physical processes of unsteady flow in tidal river are simulated experimentally in the tidal flume (width : 20 cm, high : 30 cm, length : 8 m) . This result shows that velocity profiles are composed of many patterns given by the combination of two directions of currents and magnitudes of velocity. Many fresh knowkledge about the stratification from river mouth to a drainage gate are applied to following studies.(2) The new theoretical and experimental treatments on the internal hydraulics of two-layr flows over a sill, through a contraction and the combination of them are reviewed respectively. By means of three approach (Minimal, Characteristics and Functional) , the evaluation of critical flow are summarized and discussed on the ability of development to the flow analysis.(3) The well mixed density flow in tidal river during a tidal period includes both hydraulic characteristics and un-stability problems, because of the rapid transient atratification or disappearance of internal surface. The paper reports the results of an analytical consideration depended on field data and their measurement confirmation in the Hiji River.(4) Field studies on the behavior of polluted water and sediment in or under fishery nursery in the Kitanada Bay are carried out continuously.The characteristics depended on the behavior of deficit oxygen water in the circumstances are clarified.