Rapid Assessment And Dynamic Correction Of Seismic Intensity Based On Multi-factor Control

Earthquakes are one of the most destructive disasters in nature.China is located between the western Pacific seismic belt and the Qinghai-Tibet Plateau seismic belt.It is a country with many earthquakes.According to statistics recorded by instruments since the 20th century,China accounted for 33% of global continental earthquakes,not only with high frequency but also with great intensity.During the release of energy from an earthquake,it will cause very serious disasters,and the earthquake disasters have the characteristics of high intensity,high frequency,and wide distribution.The rapid recognition of post-earthquake disasters is of great significance to the development of emergency rescue work.The earthquake intensity distribution map can intuitively and concisely express the scope of the earthquake and the extent of its damage,and it has an important effect on the distribution of relief personnel and materials and the progress of rescue work.The multi-factor-controlled rapid intensity assessment method proposed in this paper can quickly obtain the initial assessment intensity distribution map that is roughly consistent with the actual disaster situation distribution.Based on the preliminary assessment intensity circle,a dynamic intensity circle correction based on discrete intensity points is proposed.method.Can provide support for emergency rescue work.The main research contents of this article are as follows:(1)Collected Shuttle Radar Topography Mission(SRTM)data,calculated terrain gradient values in different regions based on SRTM data,and classified sites according to the principle of similarity between surface geological conditions and terrain gradients.The ground motion attenuation relationship was calculated based on the mapping method,and the ground motion parameters calculated from the ground motion attenuation relationship were corrected using the site amplification factors of different sites.Based on the conversion relationship between the ground motion parameter and the intensity,the magnitude,epicenter location,and earthquake magnitude were considered.The distribution of fault zones and other factors in the area have calculated the initial assessment intensity cycle.(2)Based on the initial assessment of the intensity circle,the location of the macro-seismic center was re-determined based on the discrete intensity points and aftershock distribution,and the long axis direction of the intensity circle was determined based on the trend of the fault zone.The statistical relationship between the intensity and the area of the intensity circle was calculated using historical earthquake case data.Based on this,the envelope of the highest discrete intensity point was expanded to obtain the highest intensity circle using an adaptive algorithm.On the basis of the maximum intensity circle,based on the statistical relationship between the intensity and the intensity circle,the maximum intensity circle is expanded,and the shape of the intensity circle is adjusted according to the discrete intensity points corresponding to the intensity,and other intensity circles are obtained in order from high to low,that is,modified After the intensity circle.(3)Design and implement the initial intensity assessment and dynamic intensity correction software;select the Jiuzhaigou earthquake to analyze the applicability of the rapid intensity assessment method and the dynamic correction method,and calculate the initial assessment intensity circle and dynamic correction of the Jiuzhaigou earthquake respectively.Intensity circle,and the accuracy assessment of the initial evaluation intensity circle and the revised intensity circle were performed.The practicability of the method described in this paper was verified.