基于水体光谱特性的赤潮分布信息MODIS遥感提取

Retrieve of Red Tide Distributions from MODIS Data Based on the Characteristics of Water Spectrum

赤潮监测对于赤潮治理、预防,减少赤潮危害有着重要作用。通过分析东海赤潮多发区域实测遥感反射率曲线,比较赤潮水体与非赤潮水体的光谱特性差异,发展了一种针对MODIS传感器的赤潮水体分布信息遥感提取方法。应用实测资料对提取方法进行验证,发现在119组实测数据中,只有一组不能正确识别。将算法应用于MODIS卫星资料,对2005年4月4日东海部分海区进行赤潮水体信息提取,得到三个区域总面积约2000km2的赤潮水体分布信息,赤潮水体提取结果与遥感提取的叶绿素a浓度有很好的对应关系,与实际观测记录对照大体吻合良好。研究表明本文的算法可有效地排除悬浮泥沙水体等干扰影响,确定可能发生赤潮的海区位置及提取海区大范围赤潮水体分布的信息。

After comparing the spectral differences between red tide water and normal water,we developed a method to retrieve red tide distributions from MODIS data based on the characteristics of red tide water spectrum.The authors used the 119 series of in situ observations to validate the method and found that only one observation has not been detected correctly.The authors then applied this method to MODIS data on April 4,2005.In the research areas three locations of red tide water were apparently detected with the total areas about 2 000 km2.The retrieved red tide distributions are in good agreement with the distributions of high chlorophyll a concentrations.The research suggests that the method is available to eliminating the influence of suspended sediments and can be used to retrieve the locations and areas of red tide water.