中文摘要：

2007年5月太湖蓝藻提前暴发，引发无锡自来水污染，出现供水危机。本文从影响蓝藻水华形成的气象要素入手，分析了无锡2007年冬春季节的气候特点。由于北方冷空气强度偏弱，位置偏北，导致2007年冬春季气候异常，气温记录连创新高，降水偏少，风向转换提前，造成越冬蓝藻种源丰富，复苏繁殖提早，从而导致蓝藻水华提前暴发。

英文摘要：

The early blue-green algae bloom in Tai Lake led to the tap water pollution and water supply crisis in May, 2007. The weather factors and climatic features in winter and spring which possibly effected the early bloom were analyzed. Results show that the abnormal weak cold air and restricted in farther northern part than usual caused high temperature in winter and spring in 2007. Air temperature broke records several times. In addition, the abnormal lack of precipitation and early wind direction deflection ahead of time resulted in abundant overwintering algae seeds in winter and early propagation in spring which were to blame for early bloom.