变化风场下太湖表层湖流特征及其对蓝藻迁移的影响

为了解太湖表层湖流对变化风场的响应特征,以及风场表层流场对蓝藻迁移的影响,通过GPS粒子示踪器对表层湖流进行观测,结合观测期间风场的变化特征和遥感图像,分析了变化风场条件下太湖的表层湖流特征以及蓝藻水华的迁移聚集过程。结果表明:太湖风场是太湖表层流场的主要驱动力,但受到地形特征、岸线特征等因素的影响,不同水域表层流场对风场的响应并不完全一致；太湖风场影响下太湖表层湖流在空间上的广泛差异性是导致蓝藻迁移过程中在不同区域聚集程度不同的主导因素,也是区域性蓝藻水华暴发的重要原因之一。风场表层流场蓝藻迁移聚集过程是一个依次传导的响应系统,条件适宜风场影响下的流场是触发蓝藻水华短时间、大面积暴发的重要外部因素。

Characteristics of surface lake current and its effect on cyanobacteria migration in Lake Taihu under changing wind field

In order to study the response characteristics of surface current to the changing wind field and the effect of wind field and surface current on the cyanobacteria migration in the Lake Taihu, systematic field observation was carried out. In this study, the surface current was observed by the GPS particle tracers, while the characteristics of surface current and the accumulation process of cyanobacteria blooms in the Lake Taihu under varying wind condition were analyzed by combining the variation characteristics of wind field and remote sensing map. The results show that the wind is the main driving force of surface current in the Lake Taihu. However, due to the influence of topographic characteristics, shoreline characteristics and et al, the response of surface current to the wind field in different water areas is not completely consistent. The surface currents of the Lake Taihu under the influence of wind field have wide spatial differences, which is the dominant factor leading to different concentrations of cyanobacteria in different areas during the migration process, and this phenomenon is one of the important reasons for the regional cyanobacteria bloom. The process of wind field, surface current and cyanobacteria migration and aggregation are a response system of successive conduction. The current field under the influence of suitable wind field is an important external factor to promote the large area of cyanobacteria blooms in a short time.