结合卫星遥感技术的太湖蓝藻水华形成风场特征

为进一步了解太湖蓝藻水华形成和分布与近地面风场的关系,利用太湖湖面及周边地区2003~2013年气象与卫星观测数据分析、并应用WRF3.5.1数值模型模拟,发现太湖蓝藻水华主要出现在卫星观测时刻前6h平均风速为0.5~3.4 m/s的区间,占比达94.7%;蓝藻水华面积总体上随风速增大而减小,大范围蓝藻水华主要出现在前6h平均风速≤2 m/s的情形下,占比达89%;风向则主要影响蓝藻水华在太湖的空间分布格局.结果表明局地风场对于太湖蓝藻水华的形成、输移和分布具有重要作用.

Analysis of wind field features causing cyanobacteria bloom in Taihu Lake combined with remote sensing methods

On the basis of the meteorological observation data and remote sensing data over the Taihu Lake and its surrounding areas during 2003 to 2013, combined with the WRF3.5.1 simulations, the relationships between the cyanobacteria blooms in Taihu Lake and surface wind speeds were analyzed. The results show that cyanobacteria blooms mainly occurred in the period of the weak wind speed about 0.5~3.4m/s, about six hours earlier than the MODIS satellite overpass time in Taihu Lake, which accounts for 94.7% of all cyanobacteria blooms events. As the area of cyanobacteria blooms decreasing with the wind speed strengthening, a large bloom of cyanobacteria bloom mainly occurred 6 hours ahead with the average wind speed less than 2m/s, accounting for 89%. In addition, the wind direction mainly affects the spatial patterns of cyanobacteria blooms in Taihu Lake. All these results suggest that the wind patterns play an important role on the formation, drifting and distribution of cyanobacteria blooms.