基于MODIS数据的5种植被指数对不同生长阶段绿潮的探测能力对比及应用

Capability Comparison of 5 Vegetation Indices for Detecting the Green Tide in Different Development Phases and the Application

本文选取晴好天气条件下的MODIS影像为研究数据,以"类间距"为评价指标,对比分析了5种常用的植被指数(NDVI、EVI、ARVI、RVI和DVI)对不同生长阶段绿潮的探测能力,在此基础上,利用最优指数开展了2014年黄海绿潮的过程分析,并与历年监测结果进行了对比。结果表明,NDVI算法对绿潮各个生长阶段的探测能力均最强。2014年黄海绿潮生消过程共计85天,绿潮密集区先向东北漂移,然后向西北漂移,最后转向东北方向漂移。最大覆盖面积为540 km2,最大分布面积为50 000 km2;与历年监测结果相比,2014年黄海绿潮的覆盖面积较小,但分布面积较大。

Five kinds of commonly used vegetation index （NDVI,EVI,ARVI,RVI and DVI）are applied to MODIS images and evaluated with respect to their detection abilities of green tide in different growth stages.And the optimal in-dex is selected to analyze the development process of green tide in the Yellow Sea in 2014.The results show that the ND-VI algorithm has the best detection capability for each development phase of the green tide.In 2014,green tide process in the Yellow Sea lastsfor 85 daysduring which the drifting direction of the greentide patches is basically northeast,then northwest,and finally northeast.The maximum coverage area is 540 km2 ,the maximum distribution area is 50 000 km2 .Compared with the green tide statistics from 2008 to 2013,the coverage area in 2014 is in the middle,but the dis-tribution area is second maximum.