基于气象条件的太湖湖泛预警研究

2007年5月与2008年5月太湖水域产生的湖泛主要是由蓝藻水华引发的,但是蓝藻水华单纯地在湖湾或岸边浅水区大量堆积并不一定引发湖泛。研究发现,2007年5月与2008年5月的湖泛现象存在相同的触发机制:3d以上时间维持高温(平均气温大于20℃),微风(平均风速小于4m/s),风向基本一致(风向平均绝对偏差小于20°);其后,冷空气过境使得风速短时增大,风向调转180°左右,气温迅速降低,并且这种气象条件持续1d以上。在此研究基础上,给出了切实可行的太湖湖泛预警方案。

The Research on Warning of Black Water Cluster in Taihu Lake Based on Meteorological Factors

The phenomenon of black odorous water masses on the water of Taihu Lake （also called ＂Hufan＂ ） in May 2007 and May 2008 was mainly caused by blue-green algal bloom.But ＂Hufan＂ does not simply result from blue-green algal bloom which moves and aggregates in the bay or shallow area.In this present study,we analyzed conventional observational data from Wuxi meteorological observing station near Taihu Lake and observed same external causes and trigger mechanism between two ＂Hufans＂ ：weather conditions of high temperature（mean temperature20℃）,gentle breeze（mean velocity4m/s） and basically-consistent wind direction（mean absolute deviation20°） last more than 3 days.Then,cold air passes through this area;air temperature drops rapidly,and wind speed increases in a short period of time,withwind deflecting approximate 180° for more than 1 day.Finally,a theoretic basis for actualizing early warning of ＇Hufan＇ in Taihu Lake was proposed.