Study On The Classification And Assessment Of Cross-border Emergent Atmospheric Environment Risk Sources

With the development of China's economy, in recent years, some large environmental pollution accidents due to leaks of toxic or hazardous materials have occurred. These accidents have caused substantial losses to society, the economy and people's lives and property. Following a chemical leak, explosions, fire and toxic chemical emissions into the atmosphere are common occurrences and can occur simultaneously, often resulting in significant atmospheric pollution and the possibility of cross-border pollution. The fundamental way of preventing or reducing cross-border air pollution emergent accident is to control potential sources of accident risks. Identifying the levels of risk of the atmospheric sources, according to the different levels, limited human, material and information resources could be allocated rationally to carry out real-time monitoring for risk sources. Therefore, it is extremely important to classify and assess the cross-border emergent atmospheric environment risk sources.In this paper, the content and results of the study include the following sections.Firstly, the concepts of cross-border emergent atmospheric environment risk source, the three elements of environmental risks source, emergent cross-border pollution are briefly discussed. The research focus of cross-border emergent atmospheric environment risk source is advanced.Secondly, a systematic review of common steps of comprehensive evaluation is made and the research progress of index system and assessment methods are discussed in detail. The characteristics and deficiency of the already applied methods are discussed respectively and a comparison is made. This study focuses on the effects of pollution incidents on sensitive receptors. A classification index system for cross-border emergent atmospheric environmental risk sources has been constructed creatively which includes indexes such as the environmental factors near the risk source and the potential for cross-border pollution that influence the extent of possible harm from a risk source, and evaluating criteria for indexes have been given. Fuzzy synthetic evaluation model based on entropy and AHP have been advanced. In order to make the result of evaluation more objective, scientific and reasonable, the entropy weight is put forward to adjust the subjective weight. Thirdly, the cross-border prediction method of atmospheric environmental risk source has been explored. Combined with the weather conditions of where the risk source located in, taking the most likely cross-border cause of the wind direction, wind speed, atmospheric stability, the area that would be affected by a cross-border atmospheric environment risk sources has been modeled by the SLAB view software to determine whether the risk is cross-border or not. The affected areas of three risk souces, a 30-tonne liquid chlorine storage tank from Dahua Fujia Chemical Co. Ltd.(example 1), an 8-tonne liquid chlorine storage tank from Kaifei Chemistry plant(example 2) and a 200-tonne liquid ammonia storage tank from Tianyuanji Chemical Co. Ltd. (example 3) in Dalian City have been modeled, results are example 1 and example 3 are cross city border atmospheric environmental risk source, example 2 is cross district border atmospheric environmental risk source.Finally, taking three major atmospheric environmental risk sources of Dagushan Chemical Industry Park in Dalian city as example, they are evaluated by Fuzzy synthetic evaluation model based on entropy and AHP. The results are that a 30-tonne liquid chlorine storage tank from Dahua Fujia Chemical Co. Ltd.(example 1) is a high environmental risk source(Grade II), while an 8-tonne liquid chlorine storage tank from Kaifei Chemistry plant(example 2) and a 200-tonne liquid ammonia storage tank from Tianyuanji Chemical Co. Ltd.(example 3) are moderate environment risk sources(Grade III). This validates that evaluation index system and evaluation methods can be applied and operated effectively.This study provides a reasonable and simple technical support to establish a "cross-border emergency air pollution incident risk prevention and response technology system" for China next step.