The Study On Site Conditions And Amplification Of Seismic Intensity Based On Ground Motion Intensity Network In Yunnan

China will finish constructing the fast-report systems of seismic intensity throughout the country in the period of the Twelfth Five-Year Plan(2011-2015). Facing the urgent seismic risk in Yunnan, the seismologists must build the fast-report system of seismic intensity based on the ground motion intensity network in Yunnan that has been implemented and put into operation during the period of the Tenth Five-Year Plan(2001-2005). However, seismologists firstly have to consider the influence of site conditions on ground motion acceleration in the study area, in order to get the real results.In view of this, considering the impact of the site conditions and amplification, the authors firstly study the fast-report systems of seismic intensity at home and abroad, and analyze the correction methods of site conditions, to explore an appropriate correction method for the fast-report system of seismic intensity in Yunnan. Secondly, by analyzing the site factors of the seismic intensity, the authors summarize the influential factors of site conditions on the fast-report system of seismic intensity. Finally, the authors apply the site correction method to the actual site conditions of the Ning’er Ms6.4earthquake zone, to verify its availability. On this basis, we explored an approach, to eliminate the impact of the site conditions to the fast-report system of seismic intensity based on ground motion intensity network in Yunnan.Through these studies, the authors conclude that by the help of Shakemap software from the United States, and under the premise of full consideration of site conditions, seismologists in Yunnan are able to carry out the fast report of the seismic intensity based on ground motion intensity network in Yunnan. Seismologists should focus on the geological conditions, topography, soil cover, etc., to study their influence to the ground motion and disaster, in order to correct the local-site amplification, and to improve accuracy of the estimated results.How to further study the influential factors of the site condition in Yunnan? The authors think that as for the geological conditions, seismologists should attach importance to seismo-tectonic background, block division, regional characteristics and activity characteristics of the seismic structure and historical seismic activity, the relationship between the earthquake structure and distribution of historical earthquakes, etc. As for the Terrain conditions, seismologists should pay close attention to the local terrain, and so on. As for the soil cover, seismologists should focus on the thickness of the soil cover of the ground motion station.