基于MODIS的2019年中国南黄海绿潮生消过程分析

Analysis of the formation and decay progress of the green tide in the southern Yellow Sea in 2019 based on MODIS

基于MODIS影像数据,通过归一化植被指数法提取2019年绿潮信息,分析了水温和降水对浒苔生消过程的影响。结果表明:2019年浒苔灾害最早出现时间为4月下旬,最晚时间为9月中旬,绿潮生消过程总体分成5个阶段,分别为初期发育期(4月下旬—5月中旬)、中期生长期(5月中旬—6月上旬)、快速生长期(6月上旬—7月上旬)、成熟白化期(7月上旬—中旬)和快速消亡期(7月中旬—9月中旬)。6月23日,绿潮覆盖面积和分布面积均达到当年峰值,分别为780 km^(2)和59420 km^(2),水温为22℃。绿潮的覆盖面积变化随水温季节性的升高呈现先上升后下降的走势,降雨对绿潮覆盖面积的增长有一定的刺激作用。

Based on the MODIS data,the green tide information of 2019 in the southern Yellow Sea is extracted using the Normalized Difference Vegetation Index method,and the influence of sea temperature and precipitation on the formation and decay process of green tide is analyzed.The results show that the green tide started in late April and ended in middle September.The green tide formation and decay can be generally divided into 5 stages,namely the initial development period(late April to mid-May),middle development period(mid-May to early June),burst period(early June to early July),mature fading(early July to mid-July)and rapid decaying(mid-July to mid-September).The sea surface temperature is 22℃on 23rd June,and the coverage area and distribution area of the green tide both reached the peak of the year,which were 780 km^(2) and 59420 km^(2),respectively.The green tide coverage area changed with the seasonal increase of sea temperature,showing a trend of first rising and then falling.The precipitation had a certain stimulating effect on the growth of green tide coverage area.