全球气候变化对太湖蓝藻水华发展演变的影响

对太湖周边4个常规气象观测站的47年观测资料进行分析,以探讨全球气候变化对太湖蓝藻水华演变的影响.结果表明,20世纪80年代之前,太湖流域气象条件的年代际尺度变化趋势不利于蓝藻的生长和水华的形成,而在20世纪80年代以后,尤其是20世纪90年代以后,气温、风速、降水变化都较大,且都有利于蓝藻的生长和水华的形成,这与蓝藻水华的观测事实一致.据此定义了蓝藻水华气象指数,每年太湖蓝藻水华气象指数能够很好地反映蓝藻水华的发展变化情况.进而,分析了反映ENSO循环变化的Ni?o3指数与太湖流域气象条件变化的相关性,结果表明ENSO循环与太湖流域风速、降水在年代际尺度上有着非常好的相关性.据此预测,2000年以后10~20年中,太湖蓝藻水华气象指数将继续在高位振荡,若蓝藻生长所需的营养盐浓度得不到有效的控制和明显的降低,蓝藻水华在气候条件的影响下,仍将可能大面积暴发.

Effect of global climate change on cyanobacteria bloom in Taihu Lake

Based on the analysis of 47 years observation data from the 4 weather stations around Taihu Lake, before the 1980's, the annual scale fluctuation of weather condition around Taihu Lake was against the growth of cyanobacteria, while it was becoming propitious for the cyanobacteria after the 1980's, especially after the 1990's with the significant change in air temperature, wind speed and precipitation. The meteorological index of the cyanobacteria bloom was defined, which was proved to be a good reflection of the annual cyanobacteria bloom situation. Furthermore, the relation between the Ni?o3 Index, a reflection of the change in ENSO circulation, and the change in climate conditions of Taihu Lake Basin was studied. An obvious relevance in annual scale between the ENSO circulation and the wind speed/precipitation was indicated in Taihu Lake Basin. During 2000 to 2020, the cyanobacteria bloom index would continue keeping in the high value. If there was no effective control and decrease in the nutrients, the cyanobacteria bloom may continue happening extensively each year in Taihu Lake.