Anomaly detection and assessment of PM10 functional data at several locations in the Klang Valley, Malaysia

Developmental Biology

Mohd Talib Latif³  Norshahida Shaadan¹  Sayang Mohd Deni¹  Abdul Aziz Jemain² 

[1] Center for Statistical and Decision Science Studies, Faculty of Computer & Mathematical Sciences, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, Malaysia$$;DELTA, School of Mathematical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia$$;School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia$$

关键词: Hexavalent chromium;    Cr(VI);    Welgegund atmospheric research station;    Atmospheric transport;    Ferrochromium;   

DOI  :  10.5094/APR.2015.040

学科分类：农业科学（综合）

来源: Dokuz Eylul Universitesi * Department of Environmental Engineering

【 摘 要 】

In environmental data sets, the occurrence of a high concentration of an unusual pollutant, more formally known as an anomaly, may indicate air quality problems. Thus, a critical understanding of the behavior of anomalies is increasingly becoming very important for air pollution investigations. This study was conducted to detect anomalies in daily PM₁₀ functional data, to investigate the patterns of behavior as well as to identify possible factors that determine PM₁₀ anomalies at three selected air quality monitoring stations (Klang, Kuala Selangor and Petaling Jaya) in the Klang Valley, Malaysia. The statistical method employed to detect these anomalies consisted of a combination of the robust projection pursuit and the robust Mahalanobis distance methods using air quality data recorded from 2005 to 2010. Analysis of obtained anomalous PM₁₀ profiles showed that data recorded during El Nino years (2005, 2006 and 2009) contained the highest frequency of anomalies. More frequent anomalies appeared during the southwest (SW) monsoon which occurs in the months of July and August as well as during the northeast (NE) monsoon in February. A lesser number of anomalies were also observed during weekends compared to weekdays. The weekend and monsoonal effect phenomena were shown to be significantly existent at all stations while wind speed was positively associated with extreme PM₁₀ anomalies at the Klang and Petaling Jaya stations. In conclusion, anomalies detection was found useful for air pollution investigation in this study. The findings of this study imply that the location and background of a station, as well as wind speed, seasonal (monsoon) and weekdays-weekend variations play important role in influencing PM₁₀ anomalies.

【 授权许可】

Unknown   

【 预 览 】

附件列表

Files	Size	Format	View
RO201912040527880ZK.pdf	1628KB	PDF