1. Seismic risk models are especially useful to develop isoseismal maps in areas where the earthquake data are only partially available.

2. Isoseismal maps are maps that show the distribution of intensities from the shaking of an earthquake with contours of equal intensity.

3. The first isoseismal lines were drawn by Liu Jichen of the earthquake of Anhui, in 1917 ( Liu Jichen, 1917).

4. What are isoseismal maps?

5. Earthquake isoseismal is usually determined based on the macroscopic earthquake affection and damages observed in the field.

6. Such maps are often referred to as isoseismal or zoning maps and depict acceleration levels predicted for different location in an earthquake zone.

7. The isoseismal maps are valuable complements to the instrumental records.

8. Their characteristics are shown clearly on the seismic deformation belts, isoseismal shapes, foreshocks and aftershocks distributions.

9. Furthermore,(http:///isoseismal.html) the image of contour picture of maximum shear stress change on orthographically rupture mode of Bohai earthquake in 1966 is closer with the macroscopic isoseismal picture.

10. A method is presented for use in establishing probability model of seismic intensity attenuation in regions with abundant data of isoseismal maps.

11. The formula of seismic intensity attenuation fitted by using 37 isoseismal lines of 14 earthquakes in Shandong and near area.

12. In this paper, a method is proposed such that the strike, dip, dipping direction and fracture length of a fault plane can be determined using of isoseismal lines.