System for creating airflow field database and system for predicting diffusion status of diffusion material

An airflow field database creation system, comprising:

• a long-term wide-area airflow field data computing unit which has, set therein, a calculation region corresponding to a geographical region of a preset breadth including a subject point where a diffusion source exists, which has also, set therein, a calculation model for obtaining weather data by computing an equation for analyzing atmospheric phenomena, which sets weather data of global weather reanalysis data being global-scale long-term wide-area actual weather data as entrance boundary conditions for the calculation region, and which performs computations by the calculation model, thereby obtaining airflow field data at predetermined certain time intervals during a predetermined certain term, the airflow field data comprising weather data at positions of a plurality of grid points set in the calculation region;
• an atmospheric stability calculation/addition unit which preselects one of the plurality of grid points as a representative grid point, and adds atmospheric stabilities to the respective airflow field data obtained by the long-term wide-area airflow field data computing unit, the atmospheric stabilities being calculated from the weather data at the positions of the representative grid points of the respective airflow field data;
• a wind direction-based/atmospheric stability-based classification unit which, based on wind directions and the atmospheric stabilities at the representative grid points for the respective airflow field data, classifies the respective airflow field data into a plurality of cases covering different combinations of the wind directions and the atmospheric stabilities;
• and
• a wind direction-based/atmospheric stability-based airflow field database creation unit which selects one of the airflow field data in a time zone, where the airflow field data exist consecutively in terms of time, as representative airflow field data for each of the cases into which the airflow field data have been classified, and associates the selected representative airflow field data with the case as the airflow field data for the case, thereby creating an airflow field database.