Study On Risk Assessment For Sudden Water Pollution Accidents In Long Distance Water Transfer Projects

Water resources are the basis for the survival and development of human beings.China’s water resources are unevenly distributed,which makes the construction of long-distance water delivery projects an inevitable trend.The long-distance water delivery project is a linear project that uses human control to transport water from areas with rich water resources to areas with scarce water resources.It mainly has the characteristics of long engineering lines,large distribution areas,and many buildings.At the same time,due to the intensive industrial enterprises along some rivers of the long-distance water delivery project,most of the main water delivery channels are responsible for shipping and other functions,which has led to the occurrence of high-frequency sudden water pollution incidents.The occurrence of sudden water pollution incidents makes it impossible to guarantee the water quality,which not only seriously threatens the lives and health of people living along the route and people in the water-receiving areas,but also hinders the local social and economic progress and sustainable ecological development.Therefore,identifying risk characteristics,building a long-distance water transportation project’s sudden water pollution risk assessment index system and carrying out risk assessment,improving the emergency response to water environment risks are particularly important for reducing or controlling sudden water pollution incidents.According to the above situation,this article starts from the characteristics of long-distance water delivery projects,taking the type of risk source and water quality as the research object.On the basis of standardized collection,literature review,and expert investigation,a reasonable and suitable indicator system for sudden water pollution risk assessment in long-distance water transportation projects is constructed and graded.At the same time,on the basis of the constructed index system,through model comparison,the normal cloud evaluation model is selected to evaluate the sudden water pollution risk by using the Yangtze River-Jihuai Project as the carrier to determine its sudden water pollution risk level.Finally,reasonable and scientific risk identification and preventive measures are provided for sudden water pollution incidents in long-distance water transportation projects.The main research contents are as follows:(1)Research on the evaluation index system of sudden water pollution accidents in long distance water transfer projects.Through the analysis of the risk factors of sudden water pollution incidents,risk investigation and risk identification are carried out,initial evaluation indicators are screened,and the final water pollution risk evaluation index system is constructed according to the DPSIR model.(2)Research on the classification of the risk assessment index of sudden water pollution accidents in long distance water transfer projects.Quantify the evaluation level of risk indicators according to the current national regulations,technical regulations,and index classification standards in related monographs.If the above standards are missing,use higher-level literature division value or expert experience standard value as a reference.(3)Study on the risk assessment model of sudden water pollution incidents in long-distance water delivery projects.Consider long-distance water project water pollution incidents are vague and random characteristics,proposed normal cloud burst water pollution risk assessment model to evaluate.First,determine the cloud model characteristic parameters according to the index value range and use the improved(G1-Gini coefficient)-particle swarm algorithm combination weighting method to calculate the weights,and then construct the membership degree matrix according to the case conditions and combine the cloud model characteristic parameters,and finally the membership degree The matrix and weight are weighted and calculated,the risk evaluation grade is determined by the principle of maximum certainty,and the tendency degree judgment of the evaluation grade is made by the characteristic value of the grade variable.(4)Case study of sudden water pollution accidents in long distance water transfer projects.Refer to the classification method of environmental emergencies in the "National Emergency Plan for Environmental Incidents",establish four evaluation sets of risk factors that are particularly significant(level I),significant(level II),large(level III)and general(level IV).Taking.The diversion of water from Yangtze River to Huaihe River were mainly divided into three sections: water diversion from Yangtze River to supply Chao Lake,Communication with Yangtze River and Huaihe River,Send water from the Yangtze River to the north.Use these three sections as a case,the risk assessment is carried out in combination with the normal cloud comprehensive evaluation model.It can be seen that the sudden water pollution risk level of the water diversion from Yangtze River to supply Chao Lake is between the II major risk and the III major risk.Most of the Communication with Yangtze River and Huaihe River are level III greater risks and some are biased towards level II major risks.Most of the sudden water pollution risk levels in the water from the Yangtze River to the north are level III greater risks and some are biased towards level II major risks.