基于MODIS的2013年黄海海域浒苔灾害的时空分布

Spatial and Temporal Distribution Characteristic of Enteromorpha in Shandong Peninsula in 2013 on the Basis of MODIS Data

基于MODIS 1B数据,根据归一化植被指数(NDVI)及假彩色合成图,设置动态阈值提取黄海海域浒苔信息,并对其时空分布特征进行了研究,结果显示:2013年黄海海域浒苔5月底开始出现,一直持续到8月上中旬.其中6月上旬是浒苔的发展期,浒苔面积、影响范围较大,相对聚集密度有所增加,此时浒苔主要分布在外海;6月中旬是浒苔的爆发期,浒苔面积和影响范围均达到最大值,6月下旬浒苔开始进入衰退期,浒苔面积、影响范围均缩小,相对聚集密度的峰值出现在该时期;8月初仅有少量浒苔漂浮在近海地带,8月21日浒苔全部消失.

Based on the MODIS 1B data,a dynamic threshold to extract information of enteromorpha in Shandong Peninsula was set according to normalized differential vegetation index（NDVI）,and the spatial and temporal distribution characteristic was carried out.The results showed that the enteromorpha began at the end of May and lasted until the middle August in the shandong peninsula waters in 2013.In early June as the development period of enteromorpha,the area and range of influence was larger and the relative packing density also increased,and at this time enteromorpha mainly distributed in the offshore.In middle June as the outbreak period of enteromorpha,the area and range of influence of enteromorpha reached the maximum.Enteromorpha entered recession period in late June.At this time,the area and range of influence of enteromorpha reduced and reached the maximum of the relative packing density.And in early August,only a little enteromorpha floated on the shore,then disappeared on August 21.