Abstract:

High speed development of remote sensing technique and high-resolution remote sensing data promotes greatly the study of active tectonics and seismo-geology.Recently,much more remote sensing techniques have widely been applied to active fault mapping.How to utilize sufficiently the various remote sensing techniques and various remote sensing data to increase the efficiency and quality of mapping has attracted eyes of many scientists.In all of the remote sensing information sources,aerial photograph has played a more important role in the interpretation of active tectonics,because of its high resolution and high intuitiveness.In the middle and late periods of last century,a lot of aerial photographs had been bought by institutes and local branches of China Earthquake Administration,especially the western provinces.These aerial photograph data are worth to pay more attention and to re-utilize when we do the active fault mapping,because of the following reasons: 1)almost no extra expense needed to be paid; 2)having excellent stereo vision; 3)having better original landform because they were shot before the high-speed economic development of the country.In this paper,some problems of air-interpretation in active fault mapping have been discussed: 1)interpreting the unusual landform,which is controlled by faulting; while the usual landform is that controlled by erosion; 2)interpreting landform classification map,because linear image is not equal to linear structure,and linear structure is not equal to active fault,either; 3)distinguishing strictly the credible,buried and conjectured fault traces; 4)restoration of offset is not only to estimate displacement along a fault but also to identify effectively whether the abnormal bending of rivers is controlled by faulting.Finally,we hope that these discussions should help the future research on the active tectonics and the active fault mapping.

Key words: active fault mapping, tectonic geomorphology, interpretation of aerial photograph

摘要：

遥感技术和高精度遥感信息的进步,极大地推动了活动构造和地震地质研究的发展,各种遥感技术在最近几年活动断层填图工作中得到了广泛的应用。如何充分利用各种遥感技术,充分挖掘各种遥感信息以提高填图工作的效率和精度,引起了广大相关科技人员的重视。航空照片以其高精度和高直观性在所有遥感信息源中占据着重要的地位。20世纪中晚期,中国地震系统曾经购入了大批航空影像资料,尤其在西部省份几乎覆盖了所有地震学者感兴趣的地区。这些航片资料具有以下几点优势,值得关注和再利用:具有优越的立体视域; 成像于改革开放之前,保存了较好的原始地形地貌。文中就活动断层填图工作中几个构造地貌航片解译的问题展开讨论,总结出航空相片目视解译的重要原则: 寻找异常地形地貌; 线性影像不等于线性构造,线性构造不等于活动断层; 要严格区分并明确断层迹线、被覆盖断层迹线和推测断层迹线; 位错复位不仅是一个估计断层走滑位错量的有效方法,也是判断水系的异常弯曲是否为断层活动结果的有效方法。希望对正在开展的活动断层填图工作和今后的研究工作有所帮助。

关键词: 活动断层填图, 构造地貌, 航片解译