The validation of the model has recently been updated in a study based on data from several years for 15 continuous measurement stations for PM10 and NO2 and additional 31 diffusive samplers for NO2 in North Rhine Westphalia. As a screening model’s main task is to identify hot spots, the relevant quality criterion is the hit rate. A hit is defined as the situation where the model correctly predicts the compliance with or violation of the respective limit values. The rate is the ratio of hits to the total number of examined situations. In its first part, this paper describes the data sets used for the model validation and shows that the model is adequate for its task together with the limits of its application. In the second part, the paper addresses the issue of deriving reliable NO2 values based on NOX.
Quality control in dispersion modeling: Validation of a screening model for PM10 and NO2
European air quality guidelines require gathering information about air quality at locations where the population is affected or possibly affected by high concentrations. High concentrations are often found in densely built up streets with high traffic loads. In order to identify these hot spots and to assess possible measures to improve the situation, screening models are widely applied in current air quality planning. Besides accomplishable data requirements, the main request for such models is to produce reliable results. The screening model IMMISluft is being widely applied throughout Germany to assess air quality in cities, e. g. for the entire Ruhr area with over 5 million inhabitants.