北京地区冬季SO_2浓度的时空分布和年际变化特征研究

用统计分析方法,对1984~1988年和1999~2000年间北京市冬季SO2的时空分布及多年变化特征进行分析,得到以下结果:(1)1984-1988年间,除定陵点位(清洁对照点)为单峰分布外,北京市SO2的城区日变化特征基本呈双峰双谷型特征分布。而在1999~2000年间,城区峰值开始降低,定陵点位峰值相对升高;(2)就多年变化特征而言,定陵点位SO2浓度呈升高趋势,且浓度高于0.03 mg/m3的事件出现频率增高;城区的SO2浓度降低,浓度高于0.3 mg/m3的事件出现频率减低。在此基础上,对影响北京市SO2的日间变化、年内变化、年际变化的污染源因子进行具体解析,发现改善燃煤质量是减少SO2排放量的有效途径。研究结论证明了城区SO2浓度水平与燃煤品质的紧密关系,对于我国各地区的SO2减排具有重要参考意义。

Study on Spatial-Temporal and Yearly Variation Characteristics of SO2 in Winter over Beijing

By using the monitoring concentration of SO2 over Beijing area in winter 1984~1988 and 1999~2000,the spatial-temporal and yearly variation of SO2 concentration are estimated.Results show that 1) Diurnal variation of SO2 concentration in urban area peaks twice in a day,the peak value descends in 1999~2000.Diurnal variation of SO2 concentration in Dingling station has a single peak in a day,the peak value ascends in 1999~2000.2) Differences of the SO2 concentration variation between 1984~1988 and 1999~2000 are compared.In Dingling station,the frequency of the occurrence of SO2 concentration(>0.03 mg · m-3) rises.In urban area,the frequency of the occurrence of SO2 concentration(>0.3 mg · m-3) falls.By analyzing pollutant source factor which influences SO2 concentration yearly variation,the authors know that improving coal quality is an effective way to reduce SO2 discharge amount.This study is meaningful for SO2 reduction in other alike regions as an important reference.