Abstract: Quantitative study of active tectonics needs to get a series of deformation parameters,and fault displacement is one of the most basic active parameters. Alluvial fan and terrace around active fault zones can record the information of time and strength of fault movement. River terrace as a most common landform contains structural information. It is meaningful for quantitative tectonic movement study to ascertain river terrace. In the article we use photogrammetric software virtuo NT to extract high resolution DEM. Based on DEM,the method and program for terrace analysis are built on the platform of ARCGIS. In the light of the distribution characteristics of slope and height,we generate the slope classification map and height classification map. And by multiplication of the two maps,the terrace landform map is generated. In the Zimakua region of Sichuan province,we applied the method to extract terrace information and got its distribution. We compared the terrace extracted based on DEM with the terrace interpreted in the filed,and the result shows that they have good consistency. The terrace boundaries record the information of fault dislocation. By measuring the dislocation of terrace boundary,we get the average dislocation of secondary fault to be 85.4m,which is in accord with the filed surveys. The results indicate that the method of terrace extraction based on DEM has the properties of high precision, high efficiency,visualization and so on.

Key words: photogrammetry, DEM, spatial analyst, terrace deformation

摘要： 河流阶地是一种最普遍的包含构造信息的地貌现象。阶地的确定与划分对于构造运动的定量研究有重要意义。文中利用数字摄影测量软件virtuoNT提取DEM,结合地貌原理,利用DEM在ARCGIS平台上建立阶地分析的处理流程,并以四川省紫马跨地区为试验区进行了阶地划分与变形分析,得到了断裂次级冲沟阶地同步位错平均约(85.4±2)m的结果,与野外检验和变形实测的结果有较好的一致性。表明利用DEM的变形阶地面提取方法具有精度高和效率高、可视化效果全面直观等特点。

关键词: 摄影测量, DEM, 空间分析, 变形阶地