An improved version of the consequence analysis model for chemical emergencies, ESCAPE. (February 2017)

• Record Type: Journal Article
• Authors: Kukkonen, J.; Nikmo, J.; Riikonen, K.
• Is Part Of: Atmospheric environment. Volume 150(2017)
• Page Start: 198
• Page End: 209
• Publication Date: 2017-02
• Subjects: Heavy gas dispersion -- Model evaluation -- Thorney Island -- Desert Tortoise -- Real-time hazard modelling -- Web browser based application; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2016.11.050
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: We present a refined version of a mathematical model called ESCAPE, "Expert System for Consequence Analysis and Preparing for Emergencies". The model has been designed for evaluating the releases of toxic and flammable gases into the atmosphere, their atmospheric dispersion and the effects on humans and the environment. We describe (i) the mathematical treatments of this model, (ii) a verification and evaluation of the model against selected experimental field data, and (iii) a new operational implementation of the model. The new mathematical treatments include state-of-the-art atmospheric vertical profiles and new submodels for dense gas and passive atmospheric dispersion. The model performance was first successfully verified using the data of the Thorney Island campaign, and then evaluated against the Desert Tortoise campaign. For the latter campaign, the geometric mean bias was 1.72 (this corresponds to an underprediction of approximately 70%) and 0.71 (overprediction of approximately 30%) for the concentration and the plume half-width, respectively. The geometric variance was <1.5 (this corresponds to an agreement that is better than a factor of two). These values can be considered to indicate a good agreement of predictions and data, in comparison to values evaluated for a range of other similar models. The model has also been adapted to be able to automatically use the real time predictions and forecasts of the numerical weather prediction model HIRLAM, "HIgh Resolution Limited Area Model". The operational implementation of the ESCAPE modelling system can be accessed anywhere using internet browsers, on laptop computers, tablets and mobile phones. The predicted results can be post-processed using geographic information systems. The model has already proved to be a useful tool of assessment for the needs of emergency response authorities in contingency planning. Graphical abstract: Highlights: A refined version of a consequence analysis model ESCAPE has been presented. The model was successfully verified against the Thorney Island field experiments. Model predictions compared well against the Desert Tortoise field experiments. An operational version of the model is used with real time weather forecasts. The model has already proved to be a useful tool for contingency planning.