The Study Of Methods For Rapid Assessment Of Seismic Intensity Distribution

China is an earthquake active country, throughout which earthquake zones are widely scattered and earthquake happens frequently and violently. Every destructive earthquake causes great casualties along with lots of damage to varying degrees and even extermination of building and civil engineering structures. emergency rescues must be launched quickly to save people's life and property by the government. Intensity isoseismal briefly shows the directly influence, damage, scope and distribution of the earthquake. It is also easily understood and accepted by the government and society, which is of extreme importance for the emergency relief deployment and action. The emergency assessment work of post-earthquake requires intensity isoseismal which is constantly revised according to the updated information. The intensity-attenuation model in matrix model mentioned in this paper can be easily used to combine historical experience value and scene investigation values so as to draw the intensity isoseismal, according which rescue effort is made.The main content of this paper is as follows:(1) Totally 138 earthquake events above 5.0 magnitude are collected. These events happened in Chinese mainland since 1966 and their data sources were credible and intensity isoseismals were relatively clear. Data arrangement and calibration work were also made for these events. Based on the statistical analysis and the application of the intensity-attenuation model in ellipse model, we got the attenuation relationship of seismic intensity along the major axis and minor axis, and we also explored the value principle of regression parameter R0 in the regression equation. In addition, this paper systematically studied the intensity characteristic of earthquakes with fault rupture outcropped on the crust surface, and made a comparison of identical degree of fault-rupture model and improved fault-rupture model which simulates the earthquake events. We suggest using the improved fault-rupture model as a supplement to simulated seismic disaster if more than 6.5 magnitude earthquake events happen. Besides, the empirical formula of equivalent rupture length and attenuation along the minor axis are given in this paper.(2) Compared with actual isoseismals, this paper finds that the intensity isoseismal drawn by the traditional ellipse model often narrows the high-intensity earthquake area and exaggerates the low-intensity earthquake area.This situation is difficult to change even we modify the regression codfficient through survey data from the earthquake field. That is because every isoseismal is only decided by three regression codfficients in the attenuation formula, and the three regression codfficients relied on each other, which makes it impossible to revise the actual isoseismal. So, this paper proposed an improved intensity-attenuation model in ellipse model, which is completed by the establishment of semi-major axis and semi-minor axis length matrix. Based on the initial value of the length matrix got by the regression of historical data and survey data from the site, we use the LMS algorithm to revise the length matrix and draw the intensity isoseismal, which is called the intensity-attenuation model in matrix model. In the end ,the the practicability of this model is verified by the case of Lijiang 7.0 earthquake.