Some System Engineering Problems Research For Earthquake Early Warning Design

In June 2015,the Project Proposal of the National Earthquake Intensity Quick Report and Early Warning Project was officially approved by the National Development and Reform Commission;in February 2017,the Feasibility Report was approved;and in June 2018,the Project Preliminary Design was approved.This nationwide large-scale system can not only improve China's earthquake foundation monitoring capability,but also play an important role in reducing earthquake damage.Based on this project,this thesis studies several system engineering problems in the design of earthquake early warning system,so as to provide operable reference for project construction.The contents are summarized as follows:(1)Based on several key problems of the construction of earthquake early warning system,the following conclusions are drawn: At the present technical level,the minimum value of early warning blind zone is 21 km,and the warning threshold magnitude is 5.6.Considering both efficiency and construction cost,10-20 km satation spacing is a reasonable range,and further reducing this value will have a poor effect on reducing blind zone.According to the seismicity and population distribution,it can be preliminarily determined that the North China,the North-South seismic belt,the South-East coastal,and the Middle Tianshan section of Xinjiang are the key early warning areas.In the architecture design of earthquake early warning system,information release system and support system are the most critical parts,which determine the success of system's construction and operation.The public has a low level of understanding and risk tolerance of the early warning system,but has a high expectation for the effect.There are no effective countermeasures in the face of early warning,and the legal obligations are unclear.The current situation of China's earthquake network cannot meet the needs of earthquake early warning,which is mainly manifested by the insufficient density of stations and the large delay.We should make full use of the existing resources to increase the density of network and upgrade data acquisition and transfer software.(2)On the basis of population and GDP,through the scenario of Jiuzhaigou earthquake,respectively by the station distribution of the National Earthquake Intensity Quick Report and Early Warning Project completed,present,ideal and extreme cases,analyze the efficiency of earthquake early warning.According to the analysis of the rationality of the earthquake early warning system for effectiveness evaluation,the earthquake early warning effectiveness evaluation model is proposed.Using the same assumption,the evaluation model is further validated by the scenario of Wenchuan earthquake.In general,it is reasonable to take population and GDP as two basic factors to evaluate the effectiveness of earthquake early warning,for earthquakes that have already occurred,we can use actual survey data to analyze the performance of earthquake early warning systems,for target area,we can use these factors to analyze it.(3)Oriented at the National Earthquake Intensity Quick Report and Early Warning Project,the architecture of earthquake early warning system was discussed in the view of Do DAF(Department of Defense Architecture Framework).By using the design of different viewpoints and modules of Do DAF,the main business unit and the data architecture model of earthquake early warning,the function orientation and business content of each unit,the contents and flow of data and control instructions,and the interface relationship between different systems were reviewed.Compared with the traditional earthquake early warning system architecture design,Do DAF emphasizes more antagonistic and developmental,the relationships between data,capability,system,combat and service are sorted out from different perspectives;at the same time,the analysis from different perspectives also has a certain reaction to coordinate and balance between theses systems.As a standard architectural method,Do DAF provides a standard interface for communication and cooperation between different industries.(4)introduce the concept of technology readiness level,evaluate the technology readiness level of earthquake early warning based on TRL(Technology Readiness Level).Through the analysis of the current earthquake early warning technology and combine the National Earthquake Intensity Quick Report and Early Warning Project,the readiness level of the present earthquake early warning technology is obtained.In general,the technology readiness level of the National Earthquake Intensity Quick Report and Early Warning Project reach the level of industrial manufacturing and development,however,due to the lack of real test of large earthquakes,it is necessary to optimize and adjust according to the running conditions in the subsequent running process,it is the direction that needs to be emphasized in the future for the part with low technology readiness level.System design is a process of interaction between theory and practice,theory guides practice,and practice feeds back on theory.In the time of the system engineering,the design of the earthquake early warning system must draw lessons from other achievements,the inspiration of system engineering to the whole design;it also needs to be combined with the reality.While drawing on the results of other systems,it is important to note that earthquake warning has its own characteristics after all,such as the extreme demand for time.This article as a introduction of the concept of trying,there is a limit to the research,there may be many unreasonable places,many details need to be further perfect,these are all need to be improved and the research direction in the future.