海域モニタリングに適したADCPを用いた濁度の鉛直分布計測手法

摘要

At stormy weather, dredging and filling operation and so on, the water with high concentrations of solids arises in coastal sea area. Growth of seaweed and algae is obstructed to interrupt sunlight by water with this high turbidity. To make matters worse, sediments has the character to adsorb the nutrient and organic matter on those surfaces. Water involved high concentration of solids with nutrient and organic matter make seawater and seabed polluted. In order to improve them, it is very important to measure the spatial and temporal variability of solids dynamics and to monitor the coastal environment. In this study, the authors proposed a new measurement method of solids depth profiles by using Acoustic Doppler Current Profilers (ADCP). Authors regarded the propagation of ultrasonic waves as inverse problems in underwater and modeled these factors, which influences the propagation of ultrasonic waves. By using ADCP and optical turbidity sensor, the depth profile of the solids concentration can be measured. Since ADCP can be obtained the three-dimensional velocity, the present method is suitable for monitoring in order to understand the solids dynamics in seawater.%出水時における河川からの流入や波涯埋立工に伴う高濁 度水が引き起こす沿岸海域における透明度の低下は，海草や 藻類の磯焼けや養殖被害の要因の一つと考えられている．ま た，浮遊懸濁物質は，海水中における各種の有機物質や無機 物質を吸着しながら沈降し，堆積する．