Developing a two-step method for detecting red tide in East China Sea using MERIS data

摘要

Red tide is an ecological anomaly that phytoplankton in seawater suddenly proliferation or aggregation under certainenvironmental conditions and within a period of time, resulting in seawater discoloration. Red tide not only endangersmarine fisheries and aquaculture, deteriorates the marine environment, affects coastal tourist industry, but also causeshuman health problems. East China Sea (ECS) is a high incidence region of red tide disasters. Remote sensing is aneffective means of monitoring red tides. In this paper, the high-incidence area of the red tide in the East China Sea isselected as the study area, MERIS L2 data is used as the data source to analyze and compare the normalized waterradiation (nlw) spectral difference between the red tide water body and the non-red tide water body in the red tide event.Based on the spectral difference, this paper develops nlw560lw490> 1.25 and nlw681-nlw665> 0 algorithm to extractthe red tide information of ECS. Applying the algorithm to ECS, the results show that the developed model caneffectively determine the location of the red tide and correspond well with the results of the official bulletin. Thisindicates that the algorithm can effectively extract red tide information.