China News Service, Chengdu, April 21 (Liu Zhongjun, Shan Peng) "Sichuan Province Active Fault Census Project has comprehensively identified the distribution and activity of major active structures and active faults in Sichuan Province, and has achieved results in active fault detection. Many subversive understandings." Zhou Wei, director of the earthquake damage prevention department of the Sichuan Earthquake Administration, said in an interview in Chengdu on April 21.

A team of experts examines the fault in the field.

Photo courtesy of Sichuan Earthquake Administration

  Active faults are the "culprits" of earthquakes.

In order to improve the ability of Sichuan Province to resist earthquake risks, in 2018, the Sichuan Province Active Fault Census Project was officially launched.

This 5-year census will help determine the locations and hazards of strong earthquakes in Sichuan in the future, and provide information for the planning and utilization of Sichuan Province's land space, urban and rural planning and construction, site selection for major engineering projects, management of earthquake-resistant fortification requirements, and earthquake-resistant disaster relief. , earthquake disaster risk assessment and prevention, earthquake safety evaluation, etc. to provide basic support.

  Sichuan is located on the southeastern margin of the Qinghai-Tibet Plateau in the western part of mainland China. It has complex and diverse topography and complex geological structures. There are nearly 100 faults of various scales in the territory, about one third of which are active faults.

Sichuan is also one of the provinces most severely affected by earthquakes in China. In recent years, destructive earthquakes such as the 2008 Wenchuan M8.0 earthquake, the 2013 Ya'an Lushan M7.0 earthquake, and the 2017 Jiuzhaigou M7.0 earthquake have caused serious casualties and property losses.

The earthquake damage shows that the destructive power of the rapid dislocation of the fault is enormous, and the earthquake damage on the fault is particularly serious.

Experts are cleaning the trenches on site.

Photo courtesy of Sichuan Earthquake Administration

  Zhou Wei introduced that the main contents of the Sichuan active fault census project include: compiling a “1:250,000” (scale, the same below) active fault structural map in Sichuan Province, and compiling seven important faults including the Longquanshan fault and the Mabian-Leibo fault. Active fault "1:50,000" active fault strip structure map, carry out "1:10,000" active fault exploration in 11 important economic development and densely populated urban areas with fault zones passing through Kangding, Songpan, etc., and build "Sichuan Province" Active Fault Information Management System".

  Up to now, the field work of the 15 sub-projects of the project has been completed and passed the acceptance of experts, and all 73 special topics have passed the acceptance.

"This census is expected to complete all acceptance work this year." Zhou Wei said that by then, the characteristics of the spatial distribution, activity attributes, and seismogenic regularity of active faults in Sichuan, as well as the relative relationship between active faults in urban areas in the event of a strong earthquake in the future The distribution of hard-hit areas, earthquake damage classification and ground motion parameters will be given.

Group photo of the expert group at the Liangshan formation drilling site.

Photo courtesy of Sichuan Earthquake Administration

  According to Zhou Rongjun, a researcher at the Sichuan Earthquake Administration, the census found more than 10 active faults in Sichuan. The level of understanding has not been able to comprehensively screen out active faults." Zhou Rongjun said that the new findings are conducive to putting forward earthquake hazard countermeasures for active faults and corresponding urban construction planning suggestions, "The closer the buildings are to the active faults in an earthquake, the greater the damage they will suffer. Therefore, urban planning and site selection of major projects should avoid choosing places with active faults.”

  It is understood that since 2020, the census results have been successively used in earthquake prevention and disaster reduction work, including providing a scientific basis for active fault avoidance for the site selection of major projects, such as the Jiuzhaigou County General Aviation Airport Project Airport, etc.; providing earthquake prevention and disaster reduction plans for various places. Technical information on risks; earthquake safety for important cities and economic development areas.

The team of experts is looking at the formation drilling rock formations.

Photo courtesy of Sichuan Earthquake Administration

  At the same time, Sichuan has accelerated the promotion of housing and facility reinforcement projects in earthquake-prone areas. Up to now, all 37 national key districts and counties in Sichuan have completed data collection, 29,651 reinforcement projects and 46,984 new construction projects have been collected in Sichuan Province. Preliminary assessment of the seismic capacity of more than 17 million houses in 183 counties and districts in 21 cities and prefectures, and made 183 preliminary assessment maps of the seismic capacity of houses based on remote sensing and experience estimation.

  In addition to predicting earthquake information and practical applications, the census is also valuable for follow-up scientific research. Zhou Rongjun said that based on the prediction and monitoring of earthquakes, the census also aims to study the evolution of active structures, the impact of active structures on climate, and human migration. Activities and even panda migrations provide ideas.

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