The Digital Terrain Analysis Of Late Quaternary Derformation Of Anninghe Fault Zone

The development of GIS promotes the development of research on geology moveing from qualitative to semi-quantitative or quantitative direction. Using geomorphological theory to study active tectonics is a relatively mature and traditional methods. Terrain analysis is an important means of geomorphological research, digital terrain analysis (Digital Terrain Analysis, DTA) is a digital terrain information processing technology ,which calculate terrain attribute and extract feature in the digital elevation model DEM, is the Extending of scope of application on DEM .Based on DTA techniques, we do the quantitative research on morphotectonics of Anninghe fault zone and vertical dislocation analysis on the macro level. Anninghe fault zone located at the eastern edge of Tibet Plateau, the eastern part of the middle mountains , belonging to KangdianTai anticline located at west edge of Yangzi Platform, is one of the main fault of North-South tectonic belt and active block boundary fault zone with strong activities since late quaternary. It north to Xianshuihe fault, south to Zemuhe fault, east to Daliangshan fault, is the central part of eastern boundary of Sichuan-Yunnan active block with the important role.In this paper, based on the spot we extract DEM and orthoimage. In the study area Anninghe, We use checkpoints to evaluate the precision of the DEM, the calculated RMSE is15.64m,and the precision is satifactory for requirement.We use height difference shadow image method to identify faults .Based on the similar principles of restoration of the ancient topography surface, we get the biggest terrance surface (the ancient terrance surface)of the study area.on the basis, we do the trend surface analysis on both sides of fault ,and analyse changes in terrance caused by the role of fault thrust on macro-level.Through the perpendicular profile group of some obvious vertical dislocation of faults , profile interval 50m, we can more detailed identify vertical dislocation of the fault . Through the trend surface analysis on both sides of the fault, we can get the result that the maximum of the vertical dislocation is 42.8m, the minimum is 2.7m, the average dislocation roughly between 20-5m, and through the profile group direction from perpendicular to the fault we can get the result that the maximum of the vertical dislocation 35m, the minimum is 1m. The dividing of micro-topography is the continuation and in-depth of that of macro-topography and one of the means to obtain information on local terrain feature, providing special topographic informatioan for number of research domain.In this paper ,we summarized the method of micro-topography dividing. Finally, through tests we divide terrace topography in northen Anninghe Zimakua region and the Southern section of Aninghe Lugu -Xichang. In Zimakua Region.Through terrace division and deformation analysis ,we get the synchronized dislocation of terrace througu sub-fault ,and compare it with measured results, a better consistency.We do the extraction and statistical analysis of terrance based on DEM in lugu-Xichang region southern Anninghe, we can see that the terraces in both sides of Anninghe distribute unsymmetrically obviously, as for terrace located in the same section of river, on the eastern side the same level terrace is higher than terrace on the west side, slope of terraces on east side is greater than the west, slope of terraces are very different on both sides of the river, the aspect of terrace in east side of the river is South - southwest direction, while the west is North - North Eastern direction. From above all,we can know that on the eastern bank of the river present as ascending tectonic movement, movement degree become slow from north to south, east-west asymmetry during terrace development show that the terrace are structural terraces, while the multi-level terraces on the east coast of river also shows that a number of tectonic uplift period.We make an analysis on the dislocatation of the whole region landform and micro-structural geomorphylogy in Anninghe southern lugu-xichang Based on DEM and the orthoimage (including the gully horizontal dislocation) ,horizontal dislocation of the gully range from hundreds meters to tens meters, all of these show that the differences between fault-block movement against the background of a strong uplift of, as well as the sinistral strike-slip,extrusion and partial tensional characteristics of Anninghe active fault...