金昌市环境空气质量变化趋势预测与评价

Forecasting and evaluation of changing trend of environmental air quality in Jinchang

金昌市受特殊地理地貌、不利气象条件制约,被列为甘肃省重点污染城市,为了了解其未来环境空气质量变化,利用2014-2018年金昌市国控站点监测数据,首先分析金昌市首要污染物特征,发现首要污染物主要以PM_(10)为主,其次为O_(3),再次为SO_(2)和PM_(2.5),且2016年开始以O_(3)为首要污染物开始凸显;接着选取PM_(10)、O_(3)、SO_(2)、PM_(2.5)为评价因子,利用灰色系统理论预测2014-2025年SO_(2)、O_(3)、PM_(2.5)、PM_(10)的年均浓度值,预测结果显示,金昌市首要污染物主要为PM_(10),但2022年开始首要污染物转为以O_(3)为主,PM_(10)次之;最后利用模糊综合评价法对金昌市2014-2025年预测的环境空气质量进行评价。就环境空气质量而言,剔除沙尘天气影响前,逐年有所改善,但仍为二级水平;剔除沙尘天气影响后,环境空气质量于2018年起达到一级水平。

Jinchang is restricted by its special geomorphology and unfavorable meteorological conditions,and is listed as a heavy polluted city in Gansu Province.In order to know its future changes about air quality,based on the daily environmental monitoring data of Jinchang from 2014 to 2018,the characteristics of primary pollutants in Jinchang are analyzed.It is found that the primary pollutants are PM_(10),O_(3),SO_(2) and PM_(2.5),and O_(3) as the primary pollutant began to highlight in 2016.Then PM_(10),O_(3),SO_(2) and PM_(2.5) are selected as evaluation factors.The grey forecasting model is used to forecast the annual average concentration of SO_(2),O_(3),PM_(2.5) and PM_(10) in 2014-2025.The forecasting results show that the primary pollutant in Jinchang is PM_(10),however,the primary pollutant begin 2022 is O_(3),followed by PM_(10).Finally,the fuzzy comprehensive evaluation method is used to evaluate the environmental air quality of Jinchang predicted in 2014-2025.As far as the environmental air quality,it has been improved year by year before dust removal,and it is still at the second level.Nevertheless,after dust removal,the environmental air quality has reached the first level since 2018.