Evaluation of atmospheric transport for complex terrain

The wind field and the dispersion model against a nuclear accident have been developed for estimating the overall wind patterns and the concentration distributions of pollutants over complex terrain. The diagnostic mass-consistent wind field model was adopted for the generation of wind field over the whole domain using several measured data. The random walk dispersion model was used for calculating the concentration distribution of radionuclides in the atmosphere. The wind field model has been applied for evaluating the characteristics of wind patterns according to the variations of Gauss precision moduli on the hemisphere obstacle. The computed wind field has been provided to investigate the concentration distribution on the same condition. The results of wind field model showed that the horizontal and vertical wind components were strongly governed by the selection of the values of Gauss precision moduli. The results of dispersion model also showed that the concentration distribution was dependent on the standard deviation of the plume according to the atmospheric stability. (author)