Air Quality Analysis Of Jingzhou City Based On Fuzzy Comprehensive Evaluation

The annual average AQI,PM2.5 concentration,PM10 concentration and SO2 concentration of hubei province decreased year by year from 2015 to 2018.The annual average AQI,PM2.5 concentration,PM10 concentration and SO2 concentration of jingzhou city also decreased year by year,but still higher than the provincial average.There was no obvious change trend in the annual average CO concentration,annual average NO2 concentration and annual average O3 concentration of hubei province and jingzhou city.But the CO concentration in jingzhou was lower than the provincial average in 2015-2017.The concentration of NO2 in jingzhou was always higher than the provincial average level.The concentration of O3 in jingzhou was not lower than the provincial average level.It can be seen that the air quality in jingzhou was still not optimistic.Therefore,the analysis of air quality in jingzhou is beneficial to the improvement and treatment of air quality in jingzhou.The air quality of jingzhou city was analyzed from the relationship between meteorological factors and air quality and the evaluation of air quality.Correlation analysis and regression analysis were performed with SPSS software to verify the relationship between meteorological factors and air quality in jingzhou city.There was a correlation between meteorological factors and air quality in jingzhou.The results show that wind speed was a key factor affecting air quality in spring,summer and autumn,and was negatively correlated with various air quality indexes.In winter,daily evaporation was the key factor affecting air quality.In addition to positive correlation with O3 concentration value,daily evaporation was negatively correlated with other air quality indexes.As the wind direction was not good for quantitative analysis,the correlation between the air quality indexes of surrounding cities and jingzhou city was analyzed,and the results showed that jingmen city has the greatest influence on the air quality of jingzhou city.The fuzzy comprehensive evaluation method was selected in the air quality evaluation method,and the fuzzy comprehensive evaluation method was improved.The membership function was replaced by the multiple slope function,and the toxicity of the evaluation factor was added into the weight calculation.Four evaluation methods are constructed: fuzzy comprehensive evaluation method,double weighted fuzzy comprehensive evaluation method,multiple slope-fuzzy comprehensive evaluation method and double weighted slope slant-fuzzy comprehensive evaluation method.Matlab software was used to write calculation program for grade calculation.The results showed that these four methods were more relaxed than air quality index evaluation methods.But the fuzzy comprehensive evaluation method takes into account the fuzziness of the grade.After adding the weight of toxicity,different degrees of influence of each evaluation factor on the whole air quality were taken into account.After replacing the membership function with the multiple slope function,the evaluation grade was more strict.The results showed that the fuzzy comprehensive evaluation method was the best of the four methods.According to the double weighted multiple slope--fuzzy comprehensive evaluation,the air quality in jingzhou was improving year by year.And pollution days occur mainly in autumn and winter.