Research On The Relation Based On ARCGIS Between The Seismicity And Active Faults Zong In Xiamen And Near Area

Earthquake brought huge disaster to mankind, which caused the damage and casualties much larger than any other natural disaster. Seismic activities are controlled by the seismic active fault zone. The correlation between seismic activity and active fault zone has been one of the focus of the earthquake and geology. Previous studies have not researched on it from quantitative to qualitative level, one of the main reasons is lack of effective spatial analysis and statistics tools. GIS technology since its inception, has provided new mean and method to make the realation research on the seismic activity and seismic active faults transition from qualitative to quantitative.As Xiamen located in the middle of China southeast coastal seismic zone, which fault develops, strong earthquakes have occurred in the background of the geological structure. Over the years, the predecessors had a large number of seismic geological work and accumulated a wealth of basic information in the region. To take Xiamen for example, so this article researched on the realationship between seismicity and active fult zone in Xiamen and near area. First of all, though the ArcGIS 9.3 software as a platform to build a spatial database of Xiamen and the surrounding area, including the basic geographic data (terrain data and topographic data, etc.), the vicinity of the devastating earthquake catalog of Xiamen, directory of small earthquakes of Xiamen, active faults, remote sensing data. Secondly, ArcGIS 9.3 software implemented the spatial distribution of active faults. Finally, the earthquake epicenter and active fault zone were superimposed by use of the software overlay function, showing the spatial distribution realation between seismicity and active fult zone.Through above the research, this paper has the following conclusions:(1) This paper not only collected Xiamen active fault data, earthquake catalog and basic geographic data, but also collected major active faults and devastating earthquake catalog in Xiamen near area. So a variety of spatial data attribute information were established to provide rich data source for the future study. Secondly, the active fault, earthquake catalogs and basic geographic information were classified to storage according to their properties to provide convenient way for data query and retrieval in the future.(2) Firstly, by use of ArcGIS 9.3 software spatial analysis function, the article carried out 10km,20km and 30km buffer analysis to the active fault in Xiamen near area. In the buffer zone 10km range, the number of earthquakes per unit area were the largest. With the buffer zone expansion, the number of earthquakes growed, but per unit area growth decreased. To further determine the realationship between the scope of the earthquake and active faults, the arcticle also carried out 15km and 25km buffer analysis to in Xiamen near area. The result showed that the seismic activity concentrated in the 15km-25km region and indicated it did not necessarily occur in seismic activity fault, it may also occured in the vicinity of faults. Finally, buffer analysis for 5km and 10km of active faults in Xiamen were carried out. The result showed that the number of earthquakes per unit area were the largest in the buffer zone 10km range.(3) During the buffer analysis, we found that the convergence of active fault zone had more frequent seismic activity.(4) DEM provided great help to analyze active faults and seismic activity. Through DEM, active faults and earthquake catalog overlay analysis, we could analyze spatial distribution of active faults and seismic activity furtherly.