Abstract
A Gaussian trajectory model was developed to predict atmospheric diffusion phenomena in complex terrain. The Gaussian trajectory model has the following features.
(1) The evaluation of plume trajectory is to be made either using the potential flow model or the quasi-potential flow model, both of which were developed by authors to find the wind field over complex terrain. The use of these models allowed to find the wind components at any given points, thus facilitating the trajectory evaluation.
(2) As for the standard deviation of plume width, the parameters including terrain effects, which have been estimated on the basis of the results of wind tunnel experiments, are used.
Outdoor model experiments were conducted to examine the validity of the developed calculation model. The results obtained by the Gaussian trajectory model are in good agreement with the diffusion characteristics estimated from the outdoor experiment. A comparative study of the Gaussian trajectory model and a finite difference method model was also made. The calculation results by the two models can be said to closely agree with each other. The Gaussian trajectory model proposed in this report is almost free from computer restrictions and requires only a few of meteorological data. This model is therefore applicable to the atmospheric environment assessment system.
