一种区分浒苔和马尾藻的遥感方法

摘要

Both ulva prolifra and sargassum are two typical large floating algae in our country's marine disasters.It was often accompanied by the emergence of sargassum when ulva prolifra disasters erupted,which brings difficulty to remote sensing algae monitoring.According to the measured spectral data and MODIS spectral characteristics of ulva prolifra and sargassum,this paper firstly proposes the ulva prolifra and sargassum index (USI)and the sargassum index (SI)for discriminating ulva prolifra and sargassum.Then it uses the MODIS 1B data successfully distinguish ulva prolifra and sargassum in the south Yellow Sea where occurred large phytoplankton in June 20,2013 by using the USI threshold of[0.251734,0.353013]and SI threshold of 0. 640227.By analysis,sargassum mainly occurs in Qingdao sea area and accounts for about 3.7% of the total algae,which is consistent with the actual situation.%浒苔和马尾藻是我国近海藻类灾害事件中两种常见的大型漂浮藻类.鉴于在浒苔灾害爆发过程中常常伴随着马尾藻的出现,给藻类灾害遥感监测带来很多困难,该文根据浒苔和马尾藻的实测光谱数据和MODIS影像上提取的两种藻类光谱数据提出了区分浒苔和马尾藻的指数算法(USI)及马尾藻指数算法(SI).并使用2013年6月20日MODIS 1B数据,设定USI算法的阈值为[0.251734,0.353013]和SI算法的阈值0.640227,成功地实现了南黄海海域爆发的大型藻类灾害事件中浒苔和马尾藻两种主要藻类的区分,所得到的马尾藻主要集中分布在青岛附近海域,总量约占藻类总量的3.7%,分类结果与实际情况比较一致.