Exploration Model of Relations between the PM2.5 of the Air and Other Monitoring Indexes Based on VAR
PM 2.5, as an important index about air pollution, whose form and composition is very complicated, has a negative influence on humankind. The paper, according to the meteorological data from Wu Han environmental air automatic monitoring station, conducts an quantitative analysis of independence and the 6 standards of AQI ,based on VAR and Granger causality test, draws a conclusion that inhalable particles and ozone is not the source of the increase of PM 2.5.Finally. The paper establishes VCR model between PM 2.5 and CO, SO2, NO2 ,introduces the impulse response function, explores a random perturbation of a standard deviation shock effects on different indicators for monitoring. KeywordsPM2.5; air pollution; VAR model. The status and variation of air quality influences human survival, life and development. It is one of the hottest issues that draw much attention of the environmental protection and the national people. Compared to the air pollution index, the air quality index can monitor the air quality status more specifically. Among these indexes, PM2.5 is a very important index. How to carry out the relevant analysis of the PM2.5 factors and discuss the PM2.5’s distribution and variation rules through the collection of PM2.5 data, it is beneficial for the prediction, evaluation and empirical analysis and have theoretical and practical significance for making high efficient feasible emission reduction plan. I. DATA SOURCE AND PREPROCESSING A. Source of Data To analyze the influence of PM2.5 with the monitoring data of Wuhan selected from January 1, 2013 to August 26, 2013 in the attachment. B. Data pre-procession In the attachment, there is some missing data about the inhalable particles on April 29, 2013 and July 7, 2013. Besides, there are some common situations of data missing that is described in the attachment. Therefore, firstly, it introduces the basic theory and techniques of the statistical treatment of data missing. Little and Rubin[1] defined the following three different types of data-missing mechanisms; 1)Missing Completely At Random(MCAR), the data missing is irrelevant to the incomplete variable and complete variable 2)Missing At Random(MAR), the data missing completely rely on the complete variable 3)Not Missing at Random, the data missing of incomplete variable rely on the incomplete variable itself, this kind of data missing shall not be neglected. Where the complete variable refers to the variable (attribute) has no missing value. Otherwise, it will be incomplete variable. Usually, the process of missing data uses the filling method of prediction to maximize the utilization of the data obtained and construct the prediction model. In order to ensure the quality of the missing data’s quality through the other data of the corresponding points, it adopts the filling method of prediction to fill the missing data and marked the inhalable particle as inhpar and imports the selected data of the period from January 1, 2013 to April 25, 2013 into Eviews 6.0 software, the results of the data such as stationary test is in the attachment 1, the fitted equation is: ( ) 41.8666 0.5627* ( 1) (0.3169) (5.3167) (7.4048) inhpar t inhpar t = + − The predicted result on April 29, 2013 is 87.4453, rounded off to 87.it is the same as the data before June 7, 2013, the fitting result of the data is ( ) 36.0974 0.4024* ( 1) (0.2006) (5.7782) ( 6.2158) inhpar t inhpar t = − − − Correspondingly, the supplemental result is 74.3438, rounded off to 74. II. THE CORRELATIVE AND INDEPENDENT QUANTITATIVE ANALYSIS OF SIX MONITORING INDEXES IN AQI For the test of the correlation and independence among the monitoring indexes, it has great importance for judging the reasonability of the monitoring index’s setting and the mechanism analysis of the formation and propagation of PM 2.5 etc. A. Quantitative Analysis of Correlation The correlation is aim at describing the overlapped information and the dependence between different indexes, Pearson’s correlation analysis is one of the most important technical methods in the multivariate data analysis. It selects 238 pairs observed data in 6 monitoring indexes of the attachment 1, leading-in Eviews6.0, respectively named as sulfur dioxide (SO2), nitrogen dioxide (NO2), particulate matter (Inhpar), carbon monoxide (CO), smell (O3), PM 2.5 (PM), the results are as follows: 2015 AASRI International Conference on Industrial Electronics and Applications (IEA 2015) © 2015. The authors Published by Atlantis Press 308 TABLE I. 6 MONITORING INDEX DATA DESCRIPTIVE STATISTICS PM SO2 O3 NO2 INHPAR CO Mean 108.737 28.1891 52.0511 63.1051 79.1610 25.8067 Median 84.5000 24.0000 46.0000 59.0000 74.0000 23.0000 Maximum 426.000 85.0000 156.000 123.000 282.000 101.000 Minimum 22.0000 5.00000 3.00000 20.0000 18.0000 10.0000 Std.Dev 74.6960 17.7239 33.7949 24.4750 33.1286 14.1098 Skewness 1.32742 0.68193 0.73441 0.50745 1.79423 1.96787 Kurtosis 4.43919 2.54436 2.96273 2.18114 9.87485 8.16541 Jarque-Bera 90.4344 20.5049 21.4088 16.8634 591.383 418.201 Probability 0.00000 0.00004 0.00002 0.00021 0.00000 0.00000 Sum 25927.0 6709.0
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