Analysis of the interactive processes of water environment between rivers and coastal regions.

为了解东京湾及其入海河(阿拉河)的水环境相互作用过程，对东京湾及其入海河(阿拉河)进行了长期的热结构分析，并对有莱克湾与千岛河之间的悬沙输运动力学进行了分析。首先，为了揭示城市化和气候变化引起的复合环境变化的长期水温变化，结合东京市中心地区城市化进程，分析了20多年来监测的水温、城市出水温度和气温。结果表明，城市出水温度一直呈上升趋势，尤其是在冬季和初春，研究区的水温以每年0.1℃的速度上升，同一季节上升幅度更大。结果表明，城市热排放对…的影响较大。上午气温的变化比气温升高的直接影响更大，主要是由于城市化。其次，为了了解紫菜养殖设施对有里亚克湾水流系统和泥沙运动的影响，进行了水产养殖设施隔室水力阻力和流速分布的微观现场实验和宏观(海湾)尺度的水力和悬浮颗粒物(SPM)输运的数值模拟。田间试验结果表明，紫菜养殖网的阻力系数随紫菜数量的不同而变化，变化范围为0.01~0.02。紫菜养殖设施网箱和网杆的阻力与底摩擦力具有相同的数量级，但在一个潮汐周期中观察到不同的时间变化。由于紫菜网的阻力，水产养殖设施下游的表面速度降低，该设施下游的表面边界层厚度约为1米。对阿里亚克湾头部的数值模拟表明，由于水阻的相对差异，紫菜养殖区的潮流和SPM浓度降低，而航道区的潮流和SPM浓度则相反增加。较少

In order to understand the interactive process of water environment between rivers and coastal regions, the long term thermal structure analysis for Tokyo bay and its inflowing river (Ara river), and transport dynamics analysis of suspended sediment between Ariake bay and Chikugo river were performed in the present study. Firstly, to reveal long-term stream temperature variation associated with composite environmental change due to urbanization and climate change, data of stream temperature, urban effluent temperature and air temperature monitored for more than two decades are analyzed in conjunction with the urbanization in the central Tokyo area. It is clarified that the temperature of urban effluents has been increasing considerably, especially in winter and early spring, and stream temperatures in the study area show a coincidental increasing trend at the rate of 0.1℃/year and more in the same seasons. It is found that the urban thermal effluent is much more influential to the stre … More am temperature changes than the direct influence of air temperature increase mainly due to urbanization. Secondly, to understand the influence of laver aquaculture facilities on the current system and sediment transport in Ariake Bay, micro-scale field experiments to measure the hydraulic resistance and velocity distribution of a compartment of an aquaculture facility and macro-(bay-) scale numerical simulations of the hydraulic and suspended particulate matter(SPM) transport were conducted. The results of the field experiment showed that the resistance coefficient of a laver aquaculture net varied from 0.01 to 0.02, depending on the quantity of laver. The resistances of the nets and poles per a compartment of laver aquaculture facility were of the same order of magnitude as the bottom friction, but differences in temporal variation were observed during a tidal cycle. The surface velocities were reduced downstream from the aquaculture facility owing to the resistance of the laver nets and the thickness of this surface boundary layer was approximately 1 m at the downstream end of the facility. The numerical simulation of the head of Ariake Bay showed that the tidal currents and SPM concentrations are reduced in the laver farming ground area, and inversely increased in the ship path regions due to the relatively differences of hydraulic resistances. Less