北京城市森林植被区空气PM_(10)质量浓度时空变化

Spatial and Temporal Variation of PM_(10) Concentration in Urban Forest Vegetation Region

文章以美国赛默飞世尔科技公司(Thermo Fisher Scientific,USA)的TEOM-1405-D双通道颗粒物在线监测仪测定的PM_(10)浓度数据,对比分析北京市大兴南海子森林公园植被区和亦庄非植被区的PM_(10)浓度时空变化特征。结果显示:PM_(10)质量浓度表现为植被区低于非植被区,二者均表现出大致相同的日变化趋势,呈典型的双峰曲线,峰值出现在上午9:00和夜间23:00;对比分析不同月份PM_(10)质量浓度可以看出,植被区与非植被区表现为同步增加或同步降低的趋势;该研究4次降雨中,第3次降雨削减率最大,植被区为82.30%,非植被区为64.50%;第4次降雨削减率最小,植被区为13.27%,非植被区为18.89%;大风在一定程度上会降低PM_(10)等颗粒物的质量浓度,风后植被区PM_(10)均值削减率为2.19%~35.59%,非植被区PM_(10)均值削减率为7.50%~58.56%;植被区与非植被区PM_(10)质量浓度均与温度成负相关。上述结果可为北京城市森林生态建设及环境保护提供合理的科学依据。

This paper analysed temporal and spatial variation of PM10 concentration in the vegetation area of Daxing Nanhaizi Forest Park and nonvegetation area of Yizhuang in Beijiang City. The PM10 concentration was determined by TEOM-1405-D dual channel particle on-line monitor of Thermo Fisher Scientific,USA. Results show that on the whole, the PM10 concentration of vegetation area was lower than that of the non-vegetation area, both of them presented the same diurnal variation tendency, which was double peak curve. Peak appears at 9：00 and 23：00.The monthly change trend of PM10 concentration was the same in vegetation zone and nonvegetation zone. In the four rainfalls, reduction rate of the third rainfall is the largest, the vegetation area was 82.30% and the nonvegetation area was 64.50%; reduction rate of the fourth rainfall was the minimum, the vegetation area was 13.27% and the nonvegetation area was 18.89%. Wind will reduce PM10 concentration in a certain extent. After wind, reduction rate range of PM10 concentration in vegetation area was 2.19%~35.59%,and reduction rate range of PM10 concentration in nonvegetation area was 7.50% ~58.56%; PM10 concentration was negatively correlated with temperature. These results would provide a reasonable scientific basis for ecological construction and environmental protection of Beijing urban forest.