Risk Assessment And System Development Of River Drinking Water Source

Following with the rapid economic growth and the acceleration of urbanization in China,water environmental issues have become the focus of international community’s attention.Drinking water issues is related to the health of residents and the survival of human beings directly.But in recent years,the water environmental issues are getting worse.The drinking water security is threatened by pollution discharge and transport leakage accident.So,it’s imperative to study the risk assessment of river drinking water sources for protecting the water security.Based on the theory and methods of the risk assessment of drinking water sources,the risk assessment technique was studied from the perspective of risk sources.The risk probability and the index of consequences were considered adequately in this study,and the risk assessment system of river drinking water sources was developed.The county-level drinking water source in Chengdu was chosen to be a case.The research results are as follows:(1)Accident tree analysis of various risk accidents.The pollutants fall into the river and standard-exceeding of water quality were both events must occur,and the impact of the two events were higher than that of the rest events.Thus,the amount of pollutants into the river could be controlled from the aspects of source and process in risk prevention.(2)Quantitative assessment of the risk grade of drinking water source.The mobile risk source,fixed risk source and non-point source were first-grade risks,and 17 types of mobile risk sources,4 types of fixed risk sources and non-point source were the main risk sources.The risk value of risk sources: mobile risk source>non-point source>fixed risk source.The risk value of the drinking water source was 486.927 and the risk grade was first-grade.(3)Risk prevention management based on three scenarios.The distance between the location of the drinking water source and the mobile risk source and the fixed risk source were too long,so it was not recommended to locate the drinking water source downstream of the mobile risk source and the fixed risk source,nor to build bridges,roads and industrial enterprises upstream of the drinking water source.The maximum allowable transport volume of hazardous chemical substance of each bridge and the road along the river was small.The maximum allowable transport volume of benzene was selected as the maximum allowable transport volume of each mobile risk source.The calculation results of maximum concentration and flow of some pollutants of sewage were negative,indicating that such pollutants couldn’t be discharged.(4)Based on risk value and risk grade,emergency risk management measures were proposed.According to the actual situation and the risk assessment results of the drinking water source,the applicable risk management measures were put forward and the organization and responsibilities of the emergency team were clarified.The alert grade was divided into two according to the classification results of the drinking water conservation,the pollution degree and the risk grade of the drinking water source.The early alert action,emergency management measures and the later disposal after the termination of the response were put forward.(5)The risk assessment system for river drinking water sources was developed.Visual Studio 2017 software was used to compile the system code and develop the risk assessment system for river drinking water sources.The system included the start interface,input interface and output interface.After importing the data needed for risk assessment,the assessment results could be output automatically after data analysis.The system realized the visualization of risk assessment and made the assessment process more accurate and efficient.