Study On Regional Acute Environmental Risk Assessment Method

With the rapid development of urbanization and industrialization, the risk of the regional distribution environment has been intensified since the high concentration of population,infrastructure and chemical enterprises. The toxic and hazardous substances released during the accidents in chemical enterprises(fire, explosion and leakage, etc.) pose a serious threaten to human health, ecological and economy, which makes the regional environmental risk the key problem to be solved. Therefore, the enrichment and improvement of the Regional Environmental Risk Assessment(RERA) is very meaningful to optimize the industrial layout and land-use planning and improve the control measures of regional environmental risk.The challenges of RERA for large areas lie in the diversity of sources, stressors and habits and the complexity of the interaction between them. Meanwhile, the existed assessment methods do not pay enough attention on the rules of releasing risk factors, the distribution patterns of risk factors in the space, and the path and the degree of the damage on receptors caused by risk factors.To describe the environmental risk systems with limited and uncertain spatial information, Set Pair Analysis(SPA) is used in this work. The distribution of environmental risk of poisonous gases after accidents is modeled by SPA. The regional atmospheric environmental risk of Nanjing Chemical Industry Park is analyzed by SPA model in this work as an example. In order to describe the distribution of atmospheric environmental risks in different conditions, this work classifies the risks into 5 levels and discusses the value of variation uncertainty coefficient i.The generation mechanism of risk field and the influence mechanism on risk receptors are analyzed by the theory of environmental risk system in this work. The environmental risk of Nanjing Chemical Industry Park is investigated as an example. At first, the environmental risk sources are identified. Then, methods, including SPA, are used to construct environmental risk field of various risk sources. After analyzing the environmental risk receptors in the risk field, the distribution of regional environmental risk level can beobtained. The result indicates that the densely populated areas or ecologically sensitive areas located around the risk sources or the river downstream have higher environmental risk level,which is in a good agreement with the actual situation. This work suggests the prevention-oriented environmental risk management system can be established based on the classification results of the environmental risks.