基于便携式无人机SfM方法的活动构造地貌位错测量--以阿尔金断裂中段为例

Offset Measurement along Active Fault Based on Portable Unmanned Aerial Vehicle and Structure from Motion:A Case Study of the Middle Section in Altyn-Tagh Fault

基于无人机航拍影像,利用SfM(structure from motion)方法重建地表三维场景;通过软件自动提取和人工目视判读方式获取冲沟地貌;基于错断地貌复位测量方法,利用LaDiCaoz测量获取位错距离。以阿尔金断裂中段为研究对象,测量了近100组地貌位错数据,发现了5次疑似古地震造成的地表冲沟错断,其对应的累积位移距离分别为6.9、14.5、20.6、30.3、40.9 m。实验结果表明SfM方法可以为活动断裂的位错距离测量提供精细尺度的数据。

High-precision surface 3D models was reconstructed by using aerial imagery derived from unmanned aerial vehicle(UAV)by the method of structure from motion(SfM).The geometry of the offset channels were obtained by the fusion of automatic extraction and manual visual interpretation.Based on the retrodeformation of geomorphologic marker,the offset distance was measured by lateral displacement calculator(LaDiCaoz).Focused on tectonics geomorphology of the middle section of the Altyn-Tagh fault,measures nearly 100 sets of geomorphological offset data,and finds 5 cumulative offsets of 6.9、14.5、20.6、30.3、40.9 m,which may be due to multiple paleoearthquakes.The result indicates that the SfM method can provide fine scale data for offset measurement of active tectonics.