基于分形理论,使用网格法计算垭都-紫云断裂带周边60 km范围内不同走向、不同区域断裂的分形维数,并结合历史地震活动,分析了研究区内断裂带各段活动性强弱.其结果表明,断裂带整体分维值为1.32,NW向断裂分维值1.24远大于NE向断裂分维值0.95,以垭都-紫云断裂为主的NW向断裂在研究区内具有较强的控制作用;垭都-紫云断裂带威宁段分维值1.29大于关岭段1.21和紫云段1.12,表现出更强的活动性和更复杂的空间分布;研究区分维值的大小能有效反映断裂的活动性及其空间展布情况,垭都-紫云断裂带威宁段断裂处于发育的活跃阶段,存在较大的发震可能性.
Based on the fractal theory,the grid method is used to calculate the fractal dimension of faults in differ-ent directions and regions within 60 km around the Yadu-Ziyun Fault Zone.Combined with historical seismicity,the activity of each section of the fault zone in the study area is analyzed.The results indicate that the overall fractal di-mension value of the fault zone is 1.32,and the NW oriented fault fractal dimension value is 1.24,much greater than the NE oriented fault fractal dimension value of 0.95.The NW oriented fault,mainly the Yadu-Ziyun Fault,has a strong control effect in the study area.The fractal dimension value of the Weining section of the Yadu-Ziyun Fault Zone is 1.29,greater than that of the Guanling section of 1.21,and that of the Ziyun section of 1.12,exhibi-ting stronger activity and more complex spatial distribution.Studying the magnitude of the differentiation dimension can effectively reflect the activity and spatial distribution of the fault.The Weining section of the Yadu-Ziyun Fault Zone is in an active stage of development,and there is a high possibility of earthquake occurrence.