Drifting Velocity Estimation of Floating Macroalgae in the Yellow Sea and East China Sea based on hourly GOCI images

Abstract

Since 2008, the massive floating macroalgal blooms such as green and golden tides were observed every year in the Yellow Sea (YS) and East China Sea (ECS). Floating macroalgae can cause great damage to fishing operation and aquaculture facilities, many researchers have tried to reduce the damage by predicting the drift path of floating macroalgae. Remote sensing is recognized as a very powerful tool for detection and tracking the drifting macroalgae. However, there are many restrictions on continuous tracking of the same patches due to the long-term revisit period of satellite. To overcome these limitations, hourly GOCI images were used to demonstrate the drift characteristic of floating macroalgae in this study. To estimate the drift velocity of macroalgae, we select the 61 patches that were identified to be the same after 1 hour. Result from the total drifting period and distance, the average drifting velocity of green and golden-tide were estimated 1.12 km h-1 and 0.78 km h-1, respectively. However, the result of calculating the drifting velocity at 1-hour intervals, the average drifting velocity of green and golden-tide shows 1.54 km h-1 and 1.27 km h-1, respectively. In otherwords, it was estimated that the floating macroalgae moved a longer distance when the drifting distance was calculated at 1-hour intervals. It can be interpreted that 1-hour interval calculation reflects that the changeable direction and sp