Based on the current status quo of Shanghai's urban gas pipeline operation and management, this project develops and designs a GIS-based "Urban Gas Pipeline Risk Assessment System", which belongs to a product in the field of risk assessment.
To ensure the safe operation of gas pipelines, we must first know the operating status of the pipelines, predict the weak areas and hidden dangers of accidents of the pipelines, and minimize the operating risks of the gas pipelines and reduce the pipelines through testing, monitoring, maintenance and replacement of pipelines. Leakage accidents reduce the harm to society caused by gas leaks, and improve the operation level of gas pipelines.
The so-called risk assessment means using risk technology to conduct accurate quantitative analysis of the accident, time, consequences, impact, probability of occurrence, and various technical and economic effects that will occur, and provide acceptable risk levels, risk control methods and principles. Formulate effective measures to reduce systemic risks. Based on the characteristics of urban gas pipelines, this project organically combines the comprehensive assessment method PRA method and the Analytical Hierarchy Process (AHP) to propose a hierarchical comprehensive risk assessment method HPRA (Hierarchy of Probable Risk Assessment) that is suitable for the characteristics of urban gas pipelines. Based on the hierarchical comprehensive risk assessment method HPRA, a risk assessment model for urban gas pipelines is established, which realizes the function of accurate assessment of gas pipeline operation risks. The accuracy rate of assessment is more than 90%, which solves the problem of difficult control of gas pipeline operation risks at present.
The "Urban Gas Pipeline Risk Assessment System" evaluates the operational risks of a city's gas pipeline network and classifies them into different risk levels.

1. Through risk assessment of pipelines, it provides a basis for pipeline transformation, formulates a scientific transformation plan based on the assessment results, invests limited funds in the most dangerous pipeline transformation, and improves the economic benefits of the enterprise.
2. In daily inspection work, key monitoring is carried out on dangerous pipelines based on the evaluation results, and limited manpower and material resources are invested in the monitoring of dangerous pipelines to improve the self-inspection rate of air leakage, and shift from passive response to daily management to advance prevention, so that various risks can be reduced in a controlled state, the incidence of gas accidents can be reduced, and the economic and social benefits of the enterprise can be improved.
3. In the emergency repair work, based on the urban gas pipeline risk assessment system, the valves and pressure regulators to be closed on site are calculated in real time according to the coordinates of the leakage points of the on-site gas pipeline, which improves the efficiency of emergency repair, reduces the leakage of gas, reduces the cost of emergency repair. At the same time, the number of gas users affected by this leak was calculated, which improved social benefits.
4. A gas pipeline monitoring system has been established. On the basis of the urban gas pipeline risk assessment system, the construction near the pipeline is monitored, and emergency repair plans are made for possible accidents in the pipeline, which greatly reduces human damage to the pipeline during construction and the emergency repair time after damage, and saves a large amount of cost for emergency repair of pipeline leaks.
5. A steel pipe inspection system has been established. On the basis of the urban gas pipeline risk assessment system, scientific arrangements are made for cathodic protection of steel pipes and detection of damage points of steel pipes, which greatly improves the service life of steel pipes and reduces pipeline leakage accidents and renewal and maintenance costs.
   At present, the "Urban Gas Pipeline Risk Assessment System" has obtained software copyrights (Nos.: 2011 SR007175, 2011 SR012680, 2012 SR001488, etc.); in October 2008, it passed the expert acceptance organized by the Shanghai Municipal Administration Bureau and was recognized by Shanghai's scientific and technological achievements. (Certificate No.: 9312008Y1170 ). The core technology of the project has been demonstrated by the Shanghai Novelty Search Consulting Center of China Academy of Sciences: This project is novel and has generally reached the advanced level of similar international products.
   This system has been in operation in Shanghai Gas Shibei Sales Co., Ltd. for many years, and its functions such as risk assessment of pipelines, operation management of pipelines, emergency repair of pipelines, inspection of pipelines, monitoring of pipelines, and inspection of pipelines have all been recognized and praised by users. It reduces the operating costs of the enterprise and improves the economic benefits of the enterprise.