Air Quality Change And Impact Factors Analysis Based On Grey Model

Air pollution is the interaction result of natural environment and human actives. But generally speaking, pollution from natural source will recover through natural purification, so it mainly comes from human actives. On the basis of totally analyzing the current study about assessment, forecasting and impact factors of air quality, the theory, research content and methods, also calculation of grey system are graped, some exploratory studies in the aspects of air quality current situation, trend forecasting and factors analysis are made. The grey clustering model, grey correlation analysis and grey dynamic model group are made full use into air quality analysis, for improving air environment and offering the foundation for controlling air pollution.Research on grey clustering model, include whitening function, clustering weight and coefficient, then correspond Tianjin air actual value with the model, make year 2001-2010 as 10 objects, annual average concentration of SO2, NO2, PM10 as index, and catalog pollution into 4 classes. Result shows, Tianjin air quality is becoming better. Make contrast analysis with air pollution index, the two consistent at turning points and significant changing points, so grey clustering model is highly credible.The basic theory and application features of grey correlation is described; and the using conditions, calculation methods, advantage and shortage is analyzed. Then select 30 social economic indexes of 5 categories as impact factors, make correlation analysis to SO2, NO2, PM10, air quality standard rate of year 2001-2009. Result shows, industrial pollution emissions and energy consumption are main factors, and city greening factors is also important; regional value, city central heating rate, and environmental investment, total vehicle numbers have influenced in different level.On basis of analyzing grey forecasting model, condition of GM(1,1), modeling step, scope, and accuracy test method, advantage of grey dynamic mode group l, fit year 2001-2010 of Tianjin air actual value with dynamic model group, the accuracy is good, so forecast the future trend, in year 2015, PM10, SO2, NO2 concentration will all decrease, the air quality will significantly improve.