北京市大气重污染过程中AQI的时空扩散特征及其预测模型

SPATIAL TEMPORAL DIFFUSION CHARACTERISTICS AND PREDICTION MODEL OF AQI IN THE PROCESS OF HEAVY AIR POLLUTION IN BEIJING CITY

通过对北京市大气重度污染时段AQI与气象因子分析,探讨AQI的时间和空间变化特征,并建立了AQI的空间预测模型。结果表明:1)风速>2.5 m/s,且持续时间长(超过5 h)时,AQI曲线特征呈现倒"V"型。若其在1.7 m/s<风速<2.5 m/s,且持续时间短(2~3 h),则AQI曲线特征为"M"型。2)在AQI的变化过程中,若没有连续5 h超过2.5 m/s的风速,2~3 d后AQI空间特征表现为南部>中部>北部,4 d后则中部>南部>北部。3)各方向上中部和北部的AQI预测模型中幂函数模型精度最高,且两者受西南方向的影响最大。

Through the analysis of heavy air pollution AQI and meteorological factors in Beijing,the paper discussed the temporal and spatial variation characteristics of AQI,and established the spatial prediction model of AQI. The results showed that： 1） As wind speed over 2. 5 m/s,and the duration of long（ more than five hours）,the AQI curve was characterized by inverted the type of ＂V＂. If it was 1. 7 ~ 2. 5 m/s,and the duration was short（ 2 ~ 3 hours）,then the AQI curve was characterized by the type of ＂M ＂. 2） In the process of AQI changes,if there was no wind speed over 2. 5 m/s in five consecutive hours,2 ~ 3 days later,AQI spatial feature was as follows： southern middle north,after four days,the spatial feature was middle southern north. 3） Among central and northern AQI prediction models in all directions,the power function model had the highest accuracy,and both of them were influenced greatly by the southwest.