A Quantitative Parameters Extraction Study Of Active Tectonics Based On UAV Photogrammetry Technology

The active tectonics,such as active faulting and active folding,are closely related to natural disasters such as earthquakes and landslides,It is always the focus of geological research.The quantification of active tectonic research has been greatly developed since the 1980 s,The demand for the reliability and precision of the quantitative parameters of the activity is raised as the need for disaster prevention and mitigation improving over and over.In recent years,the development of UAV photogrammetry has provided strong technical support for the study of active tectonics.Especially the development of portable UAVs and high-performance graphics processing stations,make the high precision image data and digital elevation model of the target structure easily obtained.Compared to traditional measures,The UAV photogrammetry can be used to extraction more accurate and reliable quantitative parameters of activities on a smaller scale and more complex terrain.In this paper,we select the South Barkol Basin Fault and the segment of Luhuo and Dawu on Xianshuihe Fault as the research zone,attempt to explore UAV photogrammetry' application value in dip-slip fault,slip fault,and active fold and the method of extracting quantitative parameters.From west to east,the South Barkol Basin Fault is divided into several different segments,such as slid,dip-slid and active fold,most of the faults are spread over the large alluvial fan,where the offset landform is seriously damaged and the terrain is complex and varied,It is the difficulty of traditional means to interpret and extract the quantitative parameters of the fracture.The high-resolution DEM and DOM data generated by UAV photogrammetry have opened us a new ways of thinking about such research.The Xianshuihe fault is one of the most active fault in the world,The offset landform is obvious and the surface rupture is well developed with different scales tectonic topography.This paper makes use of UAV photogrammetry technique to interpret the micro geomorphological characteristics of the Luhuo Yousi point and the Dawu changzi point,extract the information about the co-seismic displacement of this 2 points.Also,we interpreted different scales of micro geomorphy based on UAV photogrammetry technology,the relationship between the micro-geomorphology of active tectonic and its relationship with fault activity has been discussed.The main contents and conclusions of the paper are as follows:(1)Introduced the working principle of UAV photogrammetry technology and Photoscan software specific data processing;According to the actual work experience,the specific requirements of the data collection are summarized;Introduced the technology of data accuracy and the application in geology.(2)Complex fault scarp positions on alluvial fan and its uplift data's extraction near Barkol Hongshan farm.Alluvial fans that are in the process of development always show complex geomorphic features due to natural modification.Accordingly,analyzing these fans whether to be influenced by tectonic deformation is one of the technique difficulties in active tectonic studies.Through detailed field investigations and paleoseismic trenching,we further used this technology obtained the topographic data of a complex alluvial fan located at the south Barkol basin fault.Point at the alluvial fans that are in the process of development,On the basis of topographic analysis and image processing for DEM,we take the research methods of surface topography of secondary partitions,cut the alluvial fans longitudinally according to the difference of its age.Through the establishment of the profile cluster within each partition,separate analysis and adjacent partition data contrast,we cleared the experience of the tectonic activity information during the development of alluvial fan,informed the tectonic vertical deformation of this fan is about 2.5m.Shows the effectiveness of this technique to identify the complex alluvial fan residual structure information and extract relevant parameters.(3)Front edge form analysis of active folds near Qianshan Village.The South Barkol Basin Fault is gradually transformed into a tectonic form of thrust at the east of the basin,and performed as thin-skinned structure at Qianshan Village.The manifestation of the front edge of the fold is linear uplift.We acquired the DEM and DOM data of one thrust lift near Qianshan Village using UAV photogrammetry technology,and the parameters such as the rise of the fold are specified.(4)Earthquake Rupture interpret and co-seismic displacement parameter extract of Luhuo segment,Xianshuihe Fault.We have carried out the trenches excavation and analysis of the fractured landform of the Yousi Village,Luhuo segment.Through the data processing of the DEM,we interpreted a length of fracture of Yousi Village.According to the method of the combination of trenches and river offset,We identified four paleo earthquake events that occurred in this point,and the total offset of the gullies is 17.5m,the coseismic displacement of the 1973 Luhuo earthquake is 4.6-4.9m.Finally,we regained the micro geomorphy of this point.(5)Earthquake Rupture interpret and co-seismic displacement parameter extract of Dawu segment,Xianshuihe Fault.We acquired the DEM and DOM data of a length of 1923 Luhuo Dawu earthquake fracture in one of the new born valley.Obtained the length of the rupture is about 300 m,At the southern end of the fracture,a bar bump was found and its offset is about 4.5m.(6)Periodization of tectonic micro geomorphy and its significance.Using UAV photogrammetry,we did lots of interpret of micro geomophy such as fault valley at the North of Xianshuihe Fault.It is believed that the different scales micro geomorphy has certain active stage,this stage has a certain relation with the habit of fault activity.The main problems of the paper :The high accuracy DEM data contains information about the whole terrain,exclude other factors and highlight specific structural features are important for using high resolution DEM data to extract quantitative parameters.The method of extracting specific structural information from the current paper is mostly manual extraction,the efficiency of this method is lower,and it may a lot of useful information from the huge DEM data,thus,we still need to develop the relevant program to make the parameters automatically extracted.The discussion about the periodization of tectonic micro geomorphy and fault activity is still on the stage of geomorphy quantitative,we still need more age datas to support the discussion.The next step:Continue to extract quantitative parameters to reduce the uncertainty of the data on the South Barkol Basin Fault and Xianshuihe fault;Get the relevant age data of the research point to extract more quantitative parameters;Make detailed interpretation of the micro geomorphy at different segments of the faults,compare the data of the big earthquake and the trench data,find more geomorphological laws of fault migration,combining relevant age data,to discuss the relationship between micro geomorphological staging and earthquake' length and short period.