渤海赤潮遥感监测方法比较研究

渤海是我国赤潮重灾区，近年来赤潮灾害频发且呈加剧趋势。有效监测渤海赤潮的发生、发展及消亡过程具有重要意义。本研究基于MODIS（moderate resolution imaging spectroradiometer）数据，比较分析了叶绿素浓度异常法、赤潮指数、波段比值法、红波段差值法、Karenia brevis指数等5种方法对渤海赤潮遥感监测的有效性。结果表明:5种方法均能有效监测到天津滨海旅游区附近海域的赤潮，不仅提取的范围与赤潮发生的最大面积相符，而且空间分布也一致。然而，由5种方法提取的秦皇岛附近海域的赤潮信息却表现出明显的差异，其中由叶绿素浓度异常法和波段比值法对赤潮信息的提取结果相对较为合理。因此，无论采用哪种方法进行赤潮监测，均需结合实地调查数据或ERGB（enhanced red-green-blue）影像等资料对不同时间、不同区域发生的赤潮的监测结果进行证实。

Comparative studies on remote sensing techniques for red tide monitoring in Bohai Sea

In Bohai Sea, one of the red-tide worst-hit areas of China, the red-tide disasters occurred frequently and aggravated in recent years.Effectively monitoring the processes of the red tide from happening to extinction is of great significance for Bohai Sea.Based on MODIS (moderate resolution imaging spectroradiometer) data, five methods including the chlorophyll concentration anomalies, the red tide index, the Rrs band ratio method, the red band difference, the Karenia brevis bloom index have been comparatively analyzed to examine their availability for red tide extraction in Bohai Sea.The results showed that these five methods could effectively extract the red tide information in the offshore area of Tianjin Binhai tourism area.Not only the range but also the spatial distribution of remote sensing detection agreed with the fact.In contrast, the red tide extraction by these five methods indicated a distinct difference in the offshore area of Qinhuangdao area, which was relatively reasonable for the chlorophyll concentration anomalies and the band ratio method.However, no matter what the method was used, the field survey data or ERGB (enhanced red-green-blue) composite was necessarily combined to validate the performance of red tide extraction at different times or in different regions.