Modeling And Digital-dynamical Emergency Response System For Abrupt Air Pollution Accidents

With the development of social economy, explosion, leakage, fire disaster and other accidental air pollution events occur more and more frequently. Accidental air pollution not only do great harm to human health and the ecological environment, but also cause great social influences. To reduce hazards to public from accident release, it’s very meaningful and of practical value to do research on modeling and emergency response plan for accidental air pollution events. Therefore, a small-scale meteorological model and two health-risk assessment model are exploited and a a digital real-time dynamic emergency response plan system is designed in this paper. At last, a application demonstration of the plan system is made.The main contents and results in this thesis are as follows:First of all, small-scale meteorological field is modeled with TAPM of Nanjing Chemical Industry Park. The selected meteorological factors are temperature, relative humidity, wind field, height of mixed layer and friction velocity. These factors have great influence on the distribution of pollutant. The results showed that TAPM is able to model the diurnal fluctuation of temperature, relative humidity, height of mixed layer and friction velocity. The related coefficients of modeling and observed temperature, relative humidity and wind speed respectively are0.71,0.69and0.51These related coefficients are significant at the0.01confidence level.Secondly, a chlorine leakage pollution is simulated with ALOHA and SLAB-AEGLs system and sensitivity analysis is performed. And an ethylene blasting event is simulated with ALOHA model and sensitivity analysis is performed too. The results show that temperature, relative humidity, type of storage tank, tank capacity, height of tank and diameter of leaking hole don’t have great influence on the result of pollution. Higher wind speed, unstable atmospheric condition, no inversion or higher inversion are helpful to dispersion. For tank leakage, the larger and higher the leaking hole is, the pollutant is more critical. Higher storage temperature contributes to pollutant too. The research shows that ALOHA is applicable for leakage, fire disaster and blast events, but it shouldn’t be applied in large-scale pollution. SLAB is a kind of heavy gas model. Therefore, it should only be applied in heavy gas release case. HYSPLIT can be used in large-scale pollution for it employs a variable meteorological field, but it doesn’t take material property into consideration. The modeling result of SLAB and HYSPLIT are concentration fields. Therefore, public exposure guidelines are needed to make risk assessment.At last, a risk assessment and digital real-time dynamic emergency response plan system is designed. The system consists of three components:base information database、meteorological model and health risk assessment system and digital real-time dynamic emergency response plan. A Geographical information system (GIS) is applied in the system. An application demonstration of the plan system is made.