利用ArcGIS平台的探索性空间数据分析(ESDA)模块,将四川省强震台所记录的芦山地震强震动进行Histogram、QQplot图、半变异协方差函数云图、Voronoi地图分析,研究芦山地震强震动的特征及原因.结果表明:原始数据不服从正态分布,以宝兴地办、宝兴民治、盐源泸沽、盐源干海等台站记录离群较为明显;经过对数变换后的强震动三分量线性关系较好,宝兴地办台站的记录未出现离群现象,宝兴民治、宝兴明礼等台记录的离群现象不太明显.东西向和南北向的地震动密集度集中在西北角,收敛过渡密度区域位于龙门山山前的大邑断裂附近,与芦山地震的发震构造有较好的一致性;垂直向的地震动记录密集度集中在北部地区,而南部较为稀疏,可能与巴颜喀拉块体前缘整体随应力场变化往南移动有关系.
Based on exploratory spatial data analysis on ArcGIS system, the characteristics and the reasons of strong motion record from Lushan Mw 7.0 earthquake are analyzed in this paper. Our results show that raw data do not obey the normal distribution and these stations, for example Baoxing Diban, Baoxing Minzhi, Yanyuan Lugu and Yanyuan Ganhai obviously have stray phenomenon. Three-component of strong motion record has the very good linear relationship after logarithmic transformation. The formal stations have the less stray phe- nomenon. The east-west and north-south seismic intensity concentrated in the northwest, Convergence transition density area is located in dayi fault near the leading edge of Longmen- shan area. And this location has good consistency of seismogenie structure of Lushan earth- quake. Vertical ground motion record intensely focused on the north, relatively sparse in south, this may be caused by the southward moving of front of Bayankala block with change of stress field.