Trends of environmental accidents and impact factors in China

An overview of the spatial and temporal variations of the environmental accidents in China in recent years was presented in this paper using available data.The results showed that the frequency of pollution accidents was significantly decreased,from 3462 in 1990 to 462 in 2007.The water and air pollution accidents were found to be the dominant types,accounting for more than 80%of the total accidents.Considering the classification of environmental accidents at 4 scales,the general environmental accident,i.e.,the least serious type,was the most frequent event,taking up 58.98%of the total pollution accidents.In addition,the distribution of environmental accidents was generally in accordance with the industrial layout in the country during the past decade.It is very important to note that the extraordinarily severe environmental accidents showed an increasing trend in underdeveloped regions,which was caused by the transfer and the development of heavy polluted industry in these areas.As to the losses of environmental accidents,the casualties presented an obvious reduction tendency,while the direct economic loss per accident tended to climb up.Furthermore,some key factors that affect the spatial and temporal tendencies of environmental accidents in China were discussed and some suggestions were put forward,hoping to shed light on environmental risk management and emergency plans making associated with environmental accidents in China.

Risk forecasting and evaluating model of Environmental pollution accident

Environmental risk(ER) factors come from ER source and they are controlled by the primary control mechanism(PCM) of environmental risk, due to the self failures or the effects of external environment risk trigger mechanism, the PCM could not work regularly any more, then, the ER factors will release environmental space, and an ER field is formed up. The forming of ER field does not mean that any environmental pollution accident(EPA) will break out; only the ER receptors are exposed in the ER field and damaged seriously, the potential ER really turns into an actual EPA. Researching on the general laws of evolving from environmental risk to EPA, this paper bring forwards a relevant concept model of risk forecasting and evaluating of EPA. This model provides some scientific methods for risk evaluation, prevention and emergency response of EPA. This model not only enriches and develops the theory system of environment safety and emergency response, but also acts as an instruction for public safety, enterprise's safety management and emergency response of the accident.

Simulation analysis of environmental risk accident and management of high-sulfur gas field development in complex terrain

Environmental risk of high sulfur gas field exploitation has become one of the hot spots of environmental management studies.Severe gas H_(2)S blowout accidents in recent years have shown that poor understanding and estimates of the poisonous gas movement could lead to dangerous evacuation delays.It is important to evaluate the real concentration of H_(2)S,especially in complex terrain.Traditional experiential models are not valid in the case of rough terrain,especially in low-lying areas where the gas accumulates.This study,using high sulfur content gas field of Sichuan“Pu Guang gas field”as study object and adopting objective diagnosis of wind field of land following coordinate three dimensions,applied Lagrangian Puff Model and breaking up technique of puffs to simulate the H_(2)S diffusion condition of blowout accidents produced in the high sulfur content gas field of complex terrain area.The results showed that the H_(2)S distribution did not occur mainly in low wind direction,and due to the obstruction of the mountain’s body,it accumulated in front of mountain on produced turn over,flowed around submitted jumping type distribution.The mountain waist near the hilltop and low hollow river valley site rapture points simulating contrast showed that the higher the rapture point,the better the diffusing condition of pollutant,the distribution of risk sensitive point decided piping rupture environmental risk size combining the H_(2)S diffusion result and residential area dispersing in the study area,synthetic judge located in the high rapture point environmental risk was smaller than the low hollow point,thus it was suggested to carryout laying of lining build of equal high line of higher terrain.According to simulation results,the environmental risk management measures aimed at putting down adverse effects were worked out.