Application of the Levenberg-Marquardt Method in Improving Technology of the Seismic Influence Field

Attenuation relation of seismic intensity is fitted by using 152 complete isoseismic lines from 65 earthquakes which were greater than M_S4.0 from 1940 to 2015 in Inner Mongolia and neighboring regions. Meanwhile, based on the difference of land form and geological structure characteristics,the study area is the divided into eastern, western and central. The intensity attenuation relationships are established separately by using the LM (Levenberg-Marquardt) method and elliptic attenuation model. Comparisons are made by using the earthquake affecting field model of North China and computed results. The analytical study shows that the relation obtained represents the features of earthquake damage distribution in the areas well, and has positive meaning to guide loss assessments immediately after a destroyed earthquake.