Study on Coastal Environmental Simulation and Measurements in Yura Bay

日本大阪湾等封闭海域的水质和自然环境因城市人类活动造成的高污染负荷而长期恶化。对于环境来说，建立一个管理体系是很重要的。为了深入了解环境，提出合适的管理体系，需要进行详细的测量和数值模拟。在本研究中，研究了位于Awaji岛南部的Yura地区海洋环境的监测、模拟和数据挖掘方法。采用主成分分析法和多元回归分析法对以每月1次为主的环境数据进行分析。明确了雨拉地区的环境特征。为了在沿海地区开发一种实用的图像测量方法，利用连接两种滤光片的数字CCD相机拍摄的海水图像来测量叶绿素的分布。测量了叶绿素的分布，并采用传统的互相关法测量了电流。将计算结果与浮标的航迹线和CFD程序计算的速度矢量进行了比较。利用考虑陆地水效应的生态系统模型，构建了水质的数值模拟方法。采用流域径流污染负荷预测方法，计算了土地负荷。数值模拟结果表明，城镇地区的负荷很大，但对沿海地区营养盐和浮游植物的影响不大。

Water quality and natural environments of the enclosed sea such as Osaka Bay in Japan, has been chronically worse by the high pollution load owing to human activities in the city. It is important for the environments to develop a management system. In order to understand the environments deeply and to propose the suitable managing system, measurements in detail and numerical simulation should be made.In this research, the monitoring, simulation and data mining method of marine environments are investigated in Yura area, where is located in the southern part of Awaji Island. Environmental data, which are mainly measured once every month, have been analyzed using the principle component and multiple regression analysis. It has clarified environmental characteristics in Yura area.In order to develop a practical image measurement method in the coastal area, chlorophyll distribution is measured by means of the images of sea water, are taken with digital CCD camera attached two kinds of optical filters. The chlorophyll distribution is measured and conventional cross-correlation method is applied to measure the current. The result is compared with the path line of a buoy and with the velocity vectors calculated by CFD code.Numerical simulation method of water qualities is constructed using the ecosystem model with land water effects. The load from land is calculated using the prediction method of run-off polluted load through river basins. The results of numerical simulation show that the load from town area is verv large, but does not affect so strong to nutritive salts and phytoplankton in the coastal areas.