Emergency warning system for atmospheric environmental pollution accidents——its construction and application

This paper intends to introduce an emergency warning system for the atmospheric environmental pollution accidents we have developed in this paper.The purpose of our warning system is to meet the needs of our country and the world to predict and warn the ever-increasing occurence of unexpected atmospheric environmental pollution accidents due to the mushrooming of nuclear power and chemical enterprises in recent decades which have brought about abrupt changes in the spatial distribution and temporal variation of hazardous gases or dusty particles and result in WRF(the mesoscale weather forecasting model),CALMET(a diagnostic 3-dimensional meteorological model) and CALPUFF(an air quality dispersion model).These models have shown excellent performance while simulating the nuclear accidents at the Fukushima Daiichi nuclear power plant in the middle of March,2011.In our paper,we have modeled the release,transportation and diffusion processes of Cs-137(caesium-137) by using this WRF-CALMET-CALPUFF system for five days,from 12th March to 16th March.During the period of nuclear accident,Cs-137 was released into atmosphere with time-specific emission rate based on the study of the accident conditions.The peak value of the warning tends to appear from 6:00 to 11:00 a.m.on 15th Mar.According to the radiation monitoring results in various prefectures in Japan,no radioactive emissions were detected during 12-14th Mar.The environmental radio level in Tokyo,Chiba,Gunma,and Kanagawa would turn up dramatically in 5:00-10:00 a.m.on 15th Mar.Meteorological field and Cs-137 transport and deposition were simulated and compared with Japanese observed data,and then we have made our evaluation of the model performance.The result we have worked out helps to find that it is in nice accord with the monitoring dataset,both in area-specific arrival time of Cs-137 and the coverage at specific times.Thus can be seen that our emergency warning system in a position to well simulate the intermittent and sporadic source like explosion or hitting of any outside sources.Meanwhile,it can also automatically download the real-time up-to-date meteorological data and calculate the meteorological field every day.Compared with the previous similar systems,ours can work out the estimation of the concentration distribution faster.Besides,the results of the estimation have higher spatiotemporal resolution,the finest one being 100 m and the time interval—1 min.Therefore,our warning system can be expected to be used to the nuclear power plants and chemical industry zones to make the quick rational decisions right after the emergent atmospheric environmental pollution accidents.