| 珠江三角洲区域污染分布及其垂直风场特征 |
| 摘要点击 2895 全文点击 1439 投稿时间：2015-05-13 修订日期：2015-07-01 |
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| 中文关键词 聚类分析 区域分布 风廓线 局地循环指数 通风量 |
| 英文关键词 cluster analysis regional distribution wind profile recirculation factor ventilation index |
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| 中文摘要 |
| 基于2014年4月~2015年3月珠江三角洲(珠三角)56个环境监测子站以及9个城市的逐时PM2.5浓度数据,对珠三角地区的颗粒物污染进行了系统聚类分析和相关性分析. 结果表明, 珠三角地区PM2.5的区域污染可分为3种类区,一为东莞、 广州、 佛山以及江门(Ⅰ型); 二为中山、 珠海、 深圳、 惠州(Ⅱ型); 三为肇庆单独为一类(Ⅲ型).其在一年中所出现的天数分别为47、 7和128 d. Ⅰ型污染时,除珠海、 深圳和惠州外,其他城市的PM2.5浓度普遍较高; Ⅱ型污染时,整个珠三角地区的PM2.5浓度均要高于50.0 μg ·m-3; Ⅲ型污染时,PM2.5浓度较高的区域主要集中在肇庆、 广州以及佛山地区.同时利用珠三角地区4台主要的风廓线雷达数据研究3种污染类型所对应的垂直风场特征发现: Ⅰ型与Ⅲ型污染状况所对应的风廓线相似,低层受东南风控制,高层为西南风,Ⅲ型的风速大于Ⅰ型风速,而Ⅱ型污染时的风速明显大于其他两种类型,其低层几乎均受偏北风影响,而高层则受偏西风的影响.Ⅱ型污染所对应的边界层中低层的风向变化很小,而其他两类则有一定的变化.同时Ⅱ型的通风量要明显大于其他两种类型,其中Ⅰ型的通风量最小. 珠三角受偏北风作用时,整个珠三角的PM2.5浓度较高; 当盛行东南风时,Ⅰ、 Ⅱ区的PM2.5浓度相对较低,而Ⅲ区的污染相对较重. |
| 英文摘要 |
| Based on the data of hourly PM2.5 concentration of 56 environmental monitoring stations and 9 cities over the Pearl River Delta (PRD) region, the distributions of PM2.5 pollution in PRD region were analyzed by systematic cluster analysis and correlational analysis. It was found that the regional pollution could be divided into 3 types. The first type was the pollution occurred in Dongguan, Guangzhou, Foshan and Jiangmen (Ⅰ type), and the second type was the pollution occurred in Zhongshan, Zhuhai, Shenzhen and Huizhou (Ⅱ type), while the last type was the pollution only occurred in Zhaoqing (Ⅲ type). During the study period, they occurred 47, 7 and 128 days, respectively. During events of pollution typeⅠ, except Zhuhai, Shenzhen and Huizhou, the PM2.5 concentrations of other cities were generally high, while the PM2.5 concentration in whole PRD region was over 50.0 μg ·m-3 during events of pollution typeⅡ. The regions with higher PM2.5concentration was mainly concentrated in Zhaoqing, Guangzhou and Foshan during events of pollution type Ⅲ. The wind data from 4 wind profile radars located in PRD region was used to study the characteristics of vertical wind field of these 3 pollution types. It was found that the wind profiles of typeⅠ and Ⅲ were similar that low layer and high layer were controlled by the southeast wind and the southwest wind, respectively. For typeⅡ, the low layer and high layer were influenced by northerly wind and westerly wind, respectively. Compared with other types, the wind speed and ventilation index of typeⅡ were much higher, and the variation of wind direction at lower-middle-layer was much smaller. When PRD region was influenced by northerly winds, the PM2.5 concentration in the entire PRD region was higher. When PRD region was controlled by southeast wind, the PM2.5 concentrations of Ⅰ and Ⅱ areas were relatively lower, while the pollution in Ⅲ area was relatively heavier. |
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