都市汚染予測のための長期平均パラモデル

抄録

Evaluating the concentration distributions of contaminants is indispensable to improving and controlling the urban atomospheric environments. Recently a law has been made in order to oblige local government of urban area, where the atomospheric environments turned remarkably bad, to enforce the climatological air pollutant predictions and establish a rule to decrease the contaminants. The climatological diffusion model consists of two submodels-the climatological plume model by Holland and the puff model whichis applicable in weakly windy and calm conditions. The former is a climatological model while the later is not. Hence it does need to develop a climatological diffusion model which is applicable in weakly windy and calm conditions.
In the present paper a simple climatological puff model (CPM, for short) derived from the stationary solution of puff equation which is called Frenkiel's solution is proposed. The following specific features of our model have been observed:
1) In case frequency of wind directions is uniform to every direction our equation exactly gives an analytical solution.
2) The form of our model is quite similar to Holland's one.
3) Maximum ground level concentration (Max. GLC) and the distance of Max. GLC from smoke source are obtained analytically.
4) The time required for computing the annual mean concentration by our model decreases to about 1/20-1/100 time that by Frenkiel's one.
5) Concentration distribution calculated by our model is quite similar to the superposition of concentrations calculated at each wind direction by Frenkiel's one.
From those observation we can conclude that our model is an efficient, practical climatological diffusion model for urban air pollutant prediction.