Remote Sensing Of Marine Disasters And Inversion Of Primary Productivity Of Marine Algae

Green tide and red tide disaster not only have natural disasters properties, but also have a significant impact of human activities feature, at the same time they affect the aquaculture industry and coastal tourism and directly harm to human health. Red tide and green tide almost become economic crisis in the marine environment, and they improve the biggest uncertainty of the ecological safety and become the biggest obstacle to the construction of marine ecological civilization. As a large marine environmental disasters Green tide shows diverse types, it is found that the brown sargassum live with ulva prolifra in june 2013, Besides the phenomenon which green tide and red tide outbreak in the same time period also occurred.Considering these scientific issues, we carried out to distinguish between green tide in seagrass and Sargassum algae, as well as green tide and identification methods of red tide based on MODIS imagery and in order to objectively evaluate algae disasters paper we also carried algae disaster primary productivity inversion, the main content and conclusions are as follows:1. Distinguish between seagrass and SargassumThis paper based on the measured and image spectral characteristics of seagrass and Sargasso curves proposed distinction between seagrass and Sargasso exponential algorithm and the Sargasso index algorithm, macroalgae disaster events seagrass and Sargasso two species distinction based on the threshold value. We usd the MODIS 1B data successfully to distinguish ulva prolifra and sargassum in the south Yellow Sea which occurs large phytoplankton in June 20, 2013 through the USI threshold of [0.251734, 0.353013] and SI threshold of 0.640227 in which the sargassum mainly occurs in Qingdao sea area and accounts for about 3.7% of the total algaes, and the result is consistent with the actual situation.2. The study of red tide and green tide distinguishGreen tide is a large floating algae and red tide is a micro-algae, both spectral characteristic curve are quite different, according to these significant differences in characteristics the corresponding algorithm is proposed to distinguish between red tide and green tide. Green tide algae and red tide algae are different to distinguish the green tide disasters and red tides at 859 nm band remote sensing reflectance, while discriminating donghaiense with seawater according Rrs（555） / Rrs（488）, by the Rrs（678） / Rrs（667） to distinguish between two types of water bodies and donghaiense water.3. Green tide and red tide marine primary productivity estimatesThis paper gets yellow sea green tide’s OPP space distribution on July 15, 2009 using VGPM model and emphatically analyzes the correlation between Ocean Primary Production with chlorophyll a and Sea Surface Temperature. The result show that the Ocean Primary Production of green tide area is higher than the normal region, the green tide ocean primary production numerical value ranges between 2600 mg C·m^-2·d^-1 to 3200 mgC·m^-2·d^-1 and the normal region numerical value between 1600 mgC·m^-2·d^-1 to 1900 mgC·m^-2·d^-1 in the study area. Meanwhile the chlorophyll a in green tide area is obviously higher than normal region, but Sea Surface Temperature is lower than normal region,but the sea surface temperature is lower a little than the normal region.