Study On The Vulnerability Assessment And Pre-control Measures Of Existing Rainwater Pipe Sections In Urban Areas

The urban rainwater pipe network system is an important part of the municipal pipe network system.It is also a complex network system.When the operational failure happens,waterlogging will cause inconvenience to pedestrians and vehicles.Even result in serious flooding,which causes casualties and great economic losses.With the increasing density of urban rainwater pipe network systems which is in operation,the safe operation of rainwater pipe networks under network conditions has attracted mass attention of many researchers and practitioners.The research and analysis show that: in the urban rainwater pipe network system,a certain section of rainwater pipeline is prone to performance degradation,operation failure,and even to flood disaster because of the interference of the external environment.In order to eliminate water on the ground surface and prevent floods,it is necessary to analyze the vulnerability of existing rainwater pipe sections.This study shows great value to the entire rainwater pipe network system.The research analyzes the formation mechanism of the existing rainwater pipe sections,and adopts a scientific and reasonable method to rank the importance of the factors that affect the vulnerability of the existing rainwater pipe sections,also it gives factors and methods for the pre-control of the vulnerability of rainwater pipe sections based on the most important factors.(1)Giving introductions of the connotation and vulnerability of urban rainwater pipe network system and the existing rainwater pipe sections.This paper summarizes the theory and methods of vulnerability research by combing a large number of domestic and foreign research literatures,expounds theresearch status and research direction of the vulnerability of rainwater pipelines,and points out the research on the vulnerability of urban rainwater pipe network systems and existing rainwater pipelines.It also gives introductions of urban rainwater pipe network systems,the concept,composition,role of the urban rainwater pipe network system and the existing rainwater pipe sections.An overview of the connotation of the vulnerability of the rainwater pipe network system and the existing rainwater pipe sections and the impact on the rainwater drainage system are also introduced.(2)Analyze the factors which affecting the vulnerability of existing rainwater pipe sections and rank them according to the importance of all the factors.This paper proposes a method to measure the vulnerability of existing rainwater pipe sections,and describes the method of constructing a network model for the vulnerability of rainwater pipes based on the method of complex network theory.The empirical analysis is performed using a specific rainwater pipe segment of a university in Xi'an as an example.This paper divides the influencing factors of the vulnerability of the existing rainwater pipeline into four categories and 20 function modules,analyzes the relationship between each function module,and uses pajek software to simulate all the conditions.A network model for vulnerability of water pipe sections.The basic topology features which commonly used in complex networks are analyzed,the concept of node importance is proposed,and key influencing factors are identified using the method of the importance of complex network vulnerability.The research results show that it is feasible to study the vulnerability of existing rainwater pipelines based on complex network methods.In the examples listed in this article,the most vulnerable factor is the diameter of the rainwater pipe.(3)Conduct pre-control measures for the most important influencing factors.The direct consequence of the vulnerability of rainwater pipelines is the waterlogging and the flooding of inspection wells,all these problems will cause uncertain flood disasters.Therefore,it is very necessary to study the vulnerability from the perspective of disaster pre-control.This article obtains research data through field research and consulting relevant experts,uses influence diagram theory and weight assignment method to identify the impact of pipe diameter in the fragile mode of therole of factors,and then put forward a feasible and effective specific pre-control measures against key influencing factors.