Air Pollution Prediction Via Graph Attention Network and Gated Recurrent Unit

PM2.5 concentration prediction is of great significance to environmental protection and human health.Achieving accurate prediction of PM2.5 concentration has become an important research task.However,PM2.5 pollutants can spread in the earth’s atmosphere,causing mutual influence between different cities.To effectively capture the air pollution relationship between cities,this paper proposes a novel spatiotemporal model combining graph attention neural network(GAT)and gated recurrent unit(GRU),named GAT-GRU for PM2.5 concentration prediction.Specifically,GAT is used to learn the spatial dependence of PM2.5 concentration data in different cities,and GRU is to extract the temporal dependence of the long-term data series.The proposed model integrates the learned spatio-temporal dependencies to capture long-term complex spatio-temporal features.Considering that air pollution is related to the meteorological conditions of the city,the knowledge acquired from meteorological data is used in the model to enhance PM2.5 prediction performance.The input of the GAT-GRU model consists of PM2.5 concentration data and meteorological data.In order to verify the effectiveness of the proposed GAT-GRU prediction model,this paper designs experiments on real-world datasets compared with other baselines.Experimental results prove that our model achieves excellent performance in PM2.5 concentration prediction.

Short-term prediction of NO_(2) and NO_(x) concentrations using multilayer perceptron neural network: a case study of Tabriz, Iran

Introduction:Due to the health effects caused by airborne pollutants in urban areas,forecasting of air quality parameters is one of the most important topics of air quality research.During recent years,statistical models based on artificial neural networks(ANNs)have been increasingly applied and evaluated for forecasting of air quality.Methods:The development of ANN and multiple linear regressions(MLRs)has been applied to short-term prediction of the NO_(2) and NO_(x) concentrations as a function of meteorological conditions.The optimum structure of ANN was determined by a trial and error method.We used hourly NO_(x) and NO_(2) concentrations and metrological parameters,automatic monitoring network during October and November 2012 for two monitoring sites(Abrasan and Farmandari sites)in Tabriz,Iran.Results:Designing of the network architecture is based on the approximation theory of Kolmogorov,and the structure of ANN with 30 neurons had the best performance.ANN trained by scaled-conjugate-gradient(trainscg)training algorithm has implemented to model.It also demonstrates that MLP neural networks offer several advantages over linear MLR models.The results show that the correlation coefficient(R2)values are 0.92 and 0/94 for NO_(2) and NO_(x) concentrations,respectively.But in MLR model,R2 values were 0.41 and 0.44 for NO_(2) and NO_(x) concentrations,respectively.Conclusions:This work shows that MLP neural networks can accurately model the relationship between local meteorological data and NO_(2) and NO_(x) concentrations in an urban environment compared to linear models.