第24届冬奥会举办地空气质量特征及环境因子响应机制

空气质量问题是近些年来广受关注的问题，尤其对国际性盛会冬奥会而言，举办地的空气质量也是其能否举办成功的重要评估标准。为评估冬奥会举办地近6 a空气质量状况及动态变化环境相应机理，该研究收集了2014年以来3个冬奥会场馆所在地（北京延庆、奥体中心和河北张家口）的空气质量数据，分别分析了3个监测点的6个空气质量指标（CO、NO₂、O₃、SO₂、PM_2.5、PM₁₀）的浓度动态，并结合2016年奥体中心的气象数据分析了6个指标环境因子的响应机制，结果表明:1)张家口空气质量相对最佳，PM_2.5达标率均在80%以上，但春季大颗粒物污染仍需治理；2)2014-2019年3个监测点的空气质量有明显改善，尤其张家口SO₂从37.50 μg/m³（2014）降至11.06 μg/m³（2019），但截至2019年奥体中心NO₂仍高于国际标准，气体污染物仍是其治理的重点；3)CO和NO²日变化呈“U型”，O³和SO²为“单峰型”，CO、O₃、SO₂季节变化明显。各空气质量指标的主要影响因子分别为CO-太阳净辐射（R_n）、NO₂-太阳净辐射（R_n）、O₃-空气温度（T_a）、SO₂-空气温度（T_a），其中风速（Ws）与各空气质量指标呈负相关关系；6个指标年最大值（7.6 mg/m³、155.5、186.9、68.4、373.2 μg/m³和465.5 μg/m³）均出现在Ws<1 m/s时；然而，由于各空气质量指标的来源及彼此转换，各空气质量指标之间的相关性强于与环境因子的相关性。

Characteristics of Six Air Quality Indexes and Their Responses to Environmental Factors in the Sites of 24th Winter Olympic Games

Air quality is a matter of great concern in recent years,it is also an important evaluation criterion for the success of the Winter Olympic Games.In order to understand the situations of air quality and environmental response mechanisms to the dynamic changes of air quality in the sites of 22^th Winter Olympic Games,the air quality data in three monitoring locations (Yanqing,Olympic Center and Zhangjiakou) were collected from 2014 to 2019.The dynamic changes of six air quality indexes (CO and NO₂ and O₃,SO₂,PM_2.5 and PM₁₀) were analyzed,respectively.Besides,the response mechanism to environmental factors were examined based on the data collected from Olympic Center in 2016.The results showed that 1) the air quality of Zhangjiakou was the best among the three locations,its emissions compliance rate of PM_2.5 was over 80%,but the large-size particulate pollution still needed to be controlled in spring.2) The air quality at the three monitoring locations was improved significantly from 2014 to 2019,especially for Zhangjiakou,with SO₂ concentration declined from 37.50 μg/m³ in 2014 to 11.06 μg/m³ in 2019.However,NO₂ concentration was still above international standards and gas pollutants were still the key governance.3) CO and NO₂ had similar diurnal dynamic of “U-type”,while O₃ and SO₂ had similar diurnal dynamic of “single-peak type”.There existed obvious seasonal variations in CO,O₃ and SO₂.The main environmental factors influencing CO,NO₂,O₃ and SO₂ were R_n,R_n,T_a and T_a,while wind speed had negative relationship to these factors.The values of the maximum concentrations of the six indexes mentioned above were 7.6 mg/m³，155.5 μg /m³，186.9μg/m³，68.4 μg/m³，373.2 μg/m³，465.5 μg/m³,respectively),which were all appeared in the wind speed less than 1 m/s.The correlation between air quality indicators was stronger than that between environmental factors due to the source and conversion of air quality indicators.