关键词: 摄影测量, DEM, 空间分析, 变形阶地

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