Comparison of River Mouth Process in Tohoku District

在6个县大学的合作下，对东北地区河口的水力和地形特征进行了调查。调查的河流如下：青森：Iwaki R.(河口稳定性和水力)，Takase R.(水质和水力)，Mabechi R.(地形变化)和Niida R.(水力)岩手：三陆海岸42条河流(地形比较)秋田：Yonehiro R.(地形变化)，Omono R.(地形变化)和Koyoshi R.(河口过程)宫城：Nanakita R.(河口过程)和Abukuma R.(河口过程)Yamagata：Mogami R.(地形变化)和AKA R.(地形变化)福岛：36条小河流(地形比较)所有河流都进行了文献和实地调查。为了讨论1989年Iwaki河口Jusanko和1990年靠近莫阿米河河口和AKA河口的Yuohama的每条河流的比较，举行了两次会议。最重要的结果是，在河口观察到的河流控制现象的规模。例如，在大尺度河流中观察到的地形变化在某些年份是不同的。另一方面，小河流的地形随河流流量的年际变化而变化，这也证实了进一步的实地调查可能需要揭示河口过程的机制。

Hydraulic and topographical characteristics of river mouth in Tohoku district were surveyed under the cooperation of the universities in six prefectures. The rivers surveyed are as follows :Aomori : Iwaki R. (stability and hydraulics at river mouth), Takase R. (water quality and hydraulics), Mabechi R. (topography change) and Niida R. (hydraulics)Iwate : 42 rivers on Sanriku Coast (Comparison of topography)Akita : Yoneshiro R. (topography change), Omono R. (topography change) and Koyoshi R. (river mouth process)Miyagi : Nanakita R. (river mouth process) and Abukuma R. (river mouth process)Yamagata : Mogami R. (topography change) and Aka R. (topography change)Fukushima : 36 small rivers (comparison of topography)Both the literature and the field survey were carried out for all rivers. Two gatherings were performed in order to discuss the comparison of each river at Jusanko, the Iwaki River mouth, 1989, and at Yunohama, near the Mogami River mouth and the Aka River mouth, 1990.The most important results obtained is that the scale of river controls phenomena observed at river mouths. For example, the topography change observed in large scale river varies over some years. On the other hand, the topography of small river varies according to annual variation of river flow.It was also confirmed that the further field survey may need to reveal the mechanism of river mouth process.