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Nakayama, Hiromasa; Takemi, Tetsuya*
Proceedings of 18th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes (HARMO-18) (USB Flash Drive), p.843 - 847, 2017/10
We have attempted to develop a practical and quick local-scale atmospheric dispersion calculation method using an overlapping technique for plume concentration distributions in an emergency response to nuclear accidents. In order to evaluate the overlapping approach, we performed LESs of turbulent flows and plume dispersion under varying mean wind directions using the meteorological data as the model input. When compared with the simulated results under the real meteorological condition, it is shown that the concentration distribution patterns are reasonably simulated by the overlapping method. It can be concluded that the atmospheric dispersion calculation method using the overlapping technique has potential performance for emergency responses to nuclear accidents.
Nakayama, Hiromasa; Katata, Genki
no journal, ,
Dry deposition is the process by which gaseous materials and aerosol particles deposit on the ground surface by turbulence or gravity settling. In Japan, many forest areas are located over hilly complex surface geometries. It is difficult to accurately estimate dry deposition amounts for such areas. To deal with the problems, we have developed a local-scale high-resolution atmospheric dispersion model using Large-Eddy Simulation at a grid scale less than 10m which can consider the turbulent effects of local terrain, buildings, and trees. In this study, we apply this model to the study forest site in the suburbs of Tokyo and investigate the relationship between the structure of the forest canopy and dry deposition amounts, considering the dry deposition process of PM2.5.