Research Of Tectonic Landform In Guizhou Based On ASTER-GDEM

As an effect of the intensive and intermittent uplift of Qinghai-Xizang Plateau in neotectonic movement, Guizhou,which is located to the southeast of Qinghai-Xizang Plateau, shows the same characters in neotectonism, which is the most important geological events in Yunnan-Guizhou district.The extensive distribution of step-like landform is the main characteristic of Guizhou region in geomorphology, which is very important to reconstruct Cenozoic evolution.Taking Guizhou and its adjacent region as research district, based on ASTER-GDEM data (30m) and using ArcGIS platform, the author extracted geomorphological surfaces with slope data and statistical method, and got precise quantitative features of step-like landforms in this region for the first time. It provides a new insight into the research of step-like landforms. research shows that there are 4 steps geomorphological surfaces in research district as follw,1840-1930m,1230-1300m,780-890m,280-410m,which accounts for 0.63%,0.93%,0.97%,1.91%of Guizhou area.It shows that Guizhou region has experienced complicated tectonic uplift since Cenozoic at least 3 times, which uplifts 300-500m for each time.and it still uplifts.It is of great importance to check the characters of faults especially active faults in the research area. Traditional geological methods are Time-consuming and laborious. Using RS and GIS techniques to extract active faults is accurate, convenient and effectively,which improves the traditional geological interpretation.Based on ASTER-GDEM and ETM data,using multiple interpretation methods, Comprehensively extract active faults and To explore the distribution and character of active faults and its reflection to tectonic landforms.About 186 faults are extracted in this thesis. These faults contain three groups of NS trending, NW trending, NE trending. According to the interpretation signs for the analysis of the character of fault, study the activity, horizontal movement features and vertical movement features of faults based on the processed data, and then summarize the features of these faults by group. Check the extracted faults combined with geological map of this area. Most of the faults are confirmed, so we are sure that it is feasible to extract fault by RS data and especially the DEM data.The paper summarizes the study progress of step-like landform in Guizhou area and the method of the extraction of active faults and the extraction of step-like landform by RS and GIS. There are less research to extract the step-like landform by analysis topography and geomorphology with the DEM data, which is the innovative points of the study.