基于MODIS影像的2016—2017年东海赤潮高发期水体时空分布及其气象控制因子分析

MODIS-based spatial and temporal distribution of waterbodies during the red tide period in the East China Seafrom 2016 to 2017 and its related meteorological control factors

近年来,东海区域赤潮灾害频发,对沿海地区的经济发展和海洋生态环境造成了极大的破坏。本研究基于赤潮暴发年2016—2017年夏季MODIS影像数据,采用半经验多光谱识别算法对东海夏季赤潮暴发期的水体类型分布特征进行反演。结果表明,赤潮高发期东海水体类型从近岸向开阔海域呈现浑浊水体-赤潮水体-混合水体-干净水体的时空分布特征。其中,硅藻和甲藻赤潮水体在空间分布上具有相互演替变化的特征。此外,通过对浙江省近岸的大陈站、石浦站和嵊泗站3个站点的气象因子进行主成分分析发现,气温、风速和天空云量对赤潮的生消演替起着积极的促进作用。

In recent years,the frequent occurrences of red tide disasters in the East China Sea have caused great damage to the economic development and marine ecological environment of coastal areas.Based on the MODIS image data in the summer of 2016-2017,a semi-empirical multispectral identification algorithm was applied to derive the distribution of water bodies during the summer red tides in the East China Sea.Results show that during the period,the water bodies from the nearshore to the open sea in the East China Sea can be classified as turbid,red tide occupied,mixed and cleared.Among them,the diatom and dinoflagellate red tide water bodies have the characteristics of mutual success in spatial distribution.In addition,through principal component analysis of meteorological factors at three stations of Dachen station,Shipu station,and Shengsi station near the coast of Zhejiang Province,It is found that temperature,wind velocity,and cloud coverage played a positive role in promoting the generation and disappearance of red tides.