川滇块体北-东边界活动构造带运动学转换与变形分解作用

青藏高原周缘活动构造带的定量运动学研究对于理解整个高原演化是一项基础性工作。利用数字摄影测量技术和区域气候-地貌-构造对比分析的年代学方法,获取了川滇块体北-东边界活动构造带内主要断裂的运动学定量数据,发现多个断裂段作为走滑活动为主的断裂在局部存在中心对称的倾向滑动分量。据矢量分析方法,将川滇块体北-东边界活动构造带及其相邻块体作为一个区域性构造系统,利用构造带内主要断裂的运动学定量数据,分析了构造带横向上的构造运动学转换关系和纵向上的变形分解作用,确定出贡嘎山隆起区存在6·2mm/a的具有透入分布式的垂直隆升速率、安宁河谷东侧台地内侧存在倾滑速率至少1·45mm/a、以逆冲为主的活动断裂。定量地建立了川滇块体北-东边界构造转折带和东边界构造带的变形分解模式,进而建立了川滇块体北-东边界活动构造带及其相邻块体组成的区域性构造系统的定量运动学模型     

USING UNMANNED AERIAL VEHICLE PHOTOGRAMMETRY TECHNOLOGY TO OBTAIN QUANTITATIVE PARAMETERS OF ACTIVE TECTONICS

With the development of photogrammetry technology and the popularity of unmanned aerial vehicles (UAVs)technology in recent years, using UAV photogrammetry technology to rapidly acquire high precision and high resolution topographic and geomorphic data on the fault zone has gradually become an important technical means. This paper first summarizes the basic principle and workflow of a new digital photogrammetry technology, SfM (Structure from Motion), which is simple, efficient and low cost. Using this technology, we conducted aerial image acquisition and data processing for a typical fault landform on the northern of Caka Basin in Qinghai. The digital elevation model (DEM)with 6.1cm/pix resolution is generated and the density of point cloud is as high as 273 points/m². The coverage area is 0.463km². Further, the terrain and slope data parallel to the fault direction are extracted by topographic analysis method, and combined with the contour map and the slope diagram generated by the DEM, a fine interpretation and quantitative study of complex multilevel geomorphic surfaces is carried out. Finally, based on the results of sophisticated interpretation of geomorphology, we got the vertical displacements of the T₁ terrace to the T₃ terrace as (1.01±0.06)m, (1.37±0.13)m and (3.10±0.11)m, and the minimum vertical displacements of the T₄ terrace and the T₅ terrace as (3.77±0.14)m and (5.46±0.26)m, respectively, through the topographic profile data extracted by DEM. Such vertical displacement parameters are difficult to obtain directly by traditional remote sensing images, which shows the great application prospect of UAV photogrammetry technology in the quantitative study of active tectonics.     

APPLICATION OF SEMIAUTOMATIC EXTRACTION OF FLUVIAL TERRACES BASED ON R LANGUAGE-AN EXAMPLE FROM THE YELLOW RIVER TERRACES AT MIJIA SHAN

The generation, abandonment and preservation of terraces formed in active tectonic areas are important to the analysis of the role of the tectonics and climate along the temporal variations, so it appears significant as how to use the effective quantitative methods to extract and accurately depict these terraces. The increasingly convenient acquisition of high-precision topographic data has greatly promoted the advancement of quantitative research in geoscience, making it possible to analyze mid-micro-geomorphic features on a large scale, especially by studying the temporal and spatial evolution of tectonic deformation through accurate capture of micro-geomorphic features. Over the past decade, the rapid development of LiDAR(Light Detection and Ranging)technology has provided unprecedented opportunity to access high-precision topographic data(up to centimeter in vertical and horizontal directions). However, its relatively high cost and relatively complex data processing techniques limit its widespread application in the field of earth sciences. In recent years, with the continuous innovation and advancement of topographic measurement technology, the three-dimensional structure of motion reconstruction technology(Structure from Motion, SfM)has gradually been introduced into the field of digital topographic photogrammetry due to its rapid advantage in providing quick, convenient and cost-effective methods for obtaining high-density geospatial point data. This method thus shows great potential for providing high resolution topographic data with comparable resolution and precision. Therefore, with the acquisition of more and more high-resolution terrain data in recent years, it is an important development trend to explore automated or semi-automated quantitative geomorphological analysis methods. R language, as an excellent programming language, has not been used in the geology and geomorphology, although is widely applied in medicine and meteorology based on its powerful capability of statistician and graphic visualization. In this paper, we focus on the Yellow River multi-terraces formed to the east of the Mijia Shan, which belongs to the Jingtai-Hasi Shan segment of the Haiyuan Fault. With the analysis and visualization of the high-resolution topographic data collected from the SfM in the environment of the R language, we implement the semiautomatic classification and mapping of the Yellow River multi-terraces. The method identifies 20 terraces with different elevation. Our results also imply that the younger terraces have better continuity and elongation, and the older terraces have more deformation, which can be demonstrated from their gradually notable semi-parabolic shape. Besides this, it also suggests the diverse evolution stages of the Yellow River terraces. Our study indicates that R language is expected to become an efficient tool of statistics and visualization of the high-resolution topographic data.     

APPLICATION OF DEM GENERATION TECHNOLOGY FROM HIGH RESOLUTION SATELLITE IMAGE IN QUANTITATIVE ACTIVE TECTONICS STUDY: A CASE STUDY OF FAULT SCARPS IN THE SOUTHERN MARGIN OF KUMISHI BASIN

Traditional method to generate Digital Elevation Model (DEM)through topographic map and topographic measurement has weak points such as low efficiency, long operating time and small range. The emergence of DEM-generation technology from high resolution satellite image provides a new method for rapid acquisition of large terrain and geomorphic data, which greatly improves the efficiency of data acquisition. This method costs lower compared with LiDAR (Light Detection and Ranging), has large coverage compared with SfM (Structure from Motion). However, there is still lack of report on whether the accuracy of DEM generated from stereo-imagery satisfies the quantitative research of active tectonics. This research is based on LPS (Leica Photogrammetry Suit)software platform, using Worldview-2 panchromatic stereo-imagery as data source, selecting Kumishi Basin in eastern Tianshan Mountains with little vegetation as study area. We generated 0.5m resolution DEM of 5-km swath along the newly discovered rupture zone at the south of Kumishi Basin, measured the height of fault scarps on different levels of alluvial fans based on the DEM, then compared with the scarp height measured by differential GPS survey in the field to analyze the accuracy of the extracted DEM. The results show that the elevation difference between the topographic profiles derived from the extracted DEM and surveyed by differential GPS ranges from -2.82 to 4.87m. The shape of the fault scarp can be finely depicted and the deviation is 0.30m after elevation correction. The accuracy of measuring the height of fault scarps can reach 0.22m, which meets the need of high-precision quantitative research of active tectonics. It provides great convenience for rapidly obtaining fine geometry, profiles morphology, vertical dislocations of fault and important reference for sites selection for trench excavation, slip rate, and samples. This method has broad prospects in the study of active tectonics.     

USING UAV PHOTOGRAMMETRY TECHNOLOGY TO EXTRACT INFORMATION OF TECTONIC ACTIVITY OF COMPLEX ALLUVIAL FAN——A CASE STUDY OF AN ALLUVIAL FAN IN THE SOUTHERN MARGIN OF BARKOL BASIN

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. Complex alluvial fans are the focus of the study of active tectonics such as fracture mapping and activity behavior analysis, for they have often retained important structural information. Traditional measurement methods, such as satellite remote sensing, RTK GPS and Lidar, are difficult to meet the demand for the study of micro tectonic deformation because of the reason of accuracy or cost performance. The recent UAV photogrammetry technology, due to its many advantages such as low cost, high resolution, and efficiency of exporting DEM and DOM data, has been widely used in three-dimensional modeling, ground mapping and other fields. In the quantitative study of active tectonics, this technology fills up the deficiency in the research of the micro structure of the traditional measurement. Through detailed field investigations and paleoseismic trenching, we further used this technology to obtain the topographic data of a complex alluvial fan located at the southern marginal fault of Barkol Basin, Xinjiang. Pointing at the alluvial fans that are in the process of development, and on the basis of topographic analysis and image processing for DEM, we take the research method of secondary partitions of the geomorphic surface and cut the alluvial fans longitudinally according to the difference of its age. Through the establishment of profile cluster within each partition, separate analysis and data contrast with the adjacent partitions, we acquired the tectonic activity information during the development of alluvial fan. The tectonic vertical deformation of this alluvial fan is about 2.5m.     

USING STEREO-PAIR AND DIFFERENTIAL GPS TO REVEAL SURFACE DEFORMATION CHARACTERISTICS OF THE MINLE-YONGCHANG FAULT

Qilian Shan-Hexi Corridor is located in the northeastern margin of the Tibetan plateau, which hosts many active strike-slip and thrust faults as well as folds. Previous study on this area was mostly concerned with large faults at the boundary of the corridor, while rare work on active tectonics in the interior of the corridor. On 25 October 2003, the Minle-Shandan M_S6.1 earthquake occurred in this area, which is related with the Minle-Yongchang fault hidden beneath the south piedmont of the Dahuangshan Mountains. As there is no obvious rupture trace on the surface, the quantitative study of this fault has never been reported so far. In order to obtain quantitative parameters of this active structure efficiently, the software of ERDAS was used to generate pointscloud data from SPOT6 stereo-pair. Two-meter resolution DEM imagery from point cloud has the line accuracy of height about 1m. Three swath profiles were extracted from the DEM data, which show that high geomorphic surfaces are all uplifted and folded. By differential GPS measurement, the vertical uplift of the thrust-related fold is estimated to be about 2.0m on the T₂, and the strike of the fold deformation is nearly 311°, which is close to the result of the fault parameter determined by aftershocks, and also in agreement with the focal mechanism solutions. Furthermore, the location of fold axial zone is consistent with the actual investigation data. These indicate that there is obvious tectonic deformation in the west part of the Minle-Yongchang fault. It supports the view that this fault is the seismogenic structure of the 2003 Minle-Shandan earthquake. Stereo-pair is of high importance in active tectonics research, which can provide significant guidance for field geologic investigations and determining the location of tectonic deformation, according to this research.     

A Review on Researches of Active Tectonics—History,Progress and Suggestions

This paper reviews the history and progress of research on active tectonics in China and overseas.By giving a brief introduction on the history of active tectonic research in China and other countries,the paper sums up the process and development of quantitative investigation of active tectonics since the 1980s.The focus is on the main efforts and progress made in China on certain aspects of research,such as basic surveys and applied investigation of active tectonics,the study of theories related to regional active tectonics and their kinematics and geodynamics,surveys on coupling relations between deep and shallow structures,active fault surveys and prospecting and seismic hazard assessment in urban areas,as well as the efforts made using Quaternary geochronology.Furthermore,the paper looks back on Chinese quantitative investigation of active tectonics in China and sums up cognitions derived from studies on the determination of several basic and measurable parameters of active tectonics.These parameters include the length of fault and fault segmentation,coseismic slip and cumulative slip,fault slip rate,the sequence of paleoearthquake events and the time elapsed since the most recent event.At the same time,efforts and progress made in China on assessing the long-term seismic potential for active faults and evaluating the risk from potential active fault movement have been reviewed by summarizing research on developing theories,models,methods and the application of time-dependent seismic potential to probabilistic assessment,magnitude estimation for potential earthquakes on active faults,and the forecast of potential risk caused by active fault movement.Finally,in consideration of the realities and problems in the research of active tectonics in China,the authors put forward several suggestions for issues worthy of more attention for further investigation in the future.     

A Review on Researches of Active Tectonics——History, Progress and Suggestions1

This paper reviews the history and progress of research on active tectonics in China and overseas. By giving a brief introduction on the history of active tectonic research in China and other countries, the paper sums up the process and development of quantitative investigation of active tectonics since the 1980s. The focus is on the main efforts and progress made in China on certain aspects of research, such as basic surveys and applied investigation of active tectonics, the study of theories related to regional active tectonics and their kinematics and geodynamics, surveys on coupling relations between deep and shallow structures, active fault surveys and prospecting and seismic hazard assessment in urban areas, as well as the efforts made using Quaternary geochronology. Furthermore, the paper looks back on Chinese quantitative investigation of active tectonics in China and sums up cognitions derived from studies on the determination of several basic and measurable parameters of active tectonics. These parameters include the length of fault and fault segmentation, coseismic slip and cumulative slip, fault slip rate, the sequence of paleoearthquake events and the time elapsed since the most recent event. At the same time, efforts and progress made in China on assessing the long-term seismic potential for active faults and evaluating the risk from potential active fault movement have been reviewed by summarizing research on developing theories, models, methods and the application of time-dependent seismic potential to prohabilistic assessment, magnitude estimation for potential earthquakes on active faults, and the forecast of potential risk caused by active fault movement. Finally, in consideration of the realities and problems in the research of active tectonics in China, the authors put forward several suggestions for issues worthy of more attention for further investigation in the future.     

THE DEVELOPMENT OF OPTICAL REMOTE SENSING TECHNOLOGY AND ITS APPLICATION TO THE ACTIVE TECTONICS RESEARCH

Remote sensing technology has brought great convenience to our understanding of the macroscopic geological features since its inception. Especially, great progress has been made in manufacturing techniques of remote sensing platforms and sensors since the mid 20th century, and a huge number of global remote sensing data have been acquired. The quality of the data has been greatly improved based on the sensor's development. This article briefly reviews the processes of development of the remote sensing technology, elaborates on several satellites' parameters which have important significance for active tectonics interpretation, such as Landsat, SPOT, QuickBird, etc., and systematically reviews the progress in optical image interpretation made with the improvement of image resolution. The paper also briefly introduces the latest optical imaging correlation techniques, the detailed geomorphological mapping techniques based high-resolution satellite images, and the perspective of application of the remote sensing technology to active tectonics research.     

高起伏区无人机摄影测量精度评估?以西秦岭光盖山-迭山断裂为例

经过近10年的迅速发展,无人机摄影测量已成为活动构造研究的常用方法之一。但对于无人机摄影测量的精度评估,尤其是高起伏地区的精度评估存在不足。为此,选择白龙江北岸光盖山-迭山断裂沿线的黑峪寺、化马村,开展无人机摄影测量,并构建正射影像（DOM）和数字地表模型（DSM）,配合差分GPS测绘进行校正和精度验证。通过对比实测控制点和图像提取点分析点精度,通过对比实测剖面与提取剖面分析剖面精度。研究结果表明,未经控制点校正的图像提取点与实测点存在较大误差,水平误差为5～8 m,垂直误差为几十米至上百米,但通过少数控制点校正后,点精度可达20 cm以内;6条实测剖面与提取剖面（提取自控制点校正后的图像）平均垂直精度总体为分米级,即0.16～0.65 m,标准差为0.13～0.69 m,略低于低起伏区的精度,对于测量条件恶劣的高起伏区,该精度是可接受的;异常高的垂直误差常出现在地形突变、低矮植被密集、行走困难等测量条件不理想位置。图像控制点中心点的准确识别、提取剖面线的修正准确性等因素也会影响精度评估的可靠性。     

焉耆盆地活动构造的遥感图像特征

焉耆盆地是一个位于天山东南部的山间盆地 ,在遥感图像上 ,可以看到盆地西面的活动构造在地表留下的痕迹 :清楚的线形构造 ,被错开的水系、冲沟等。经分析认为 ,这些活动构造主要由北边的活动褶皱和南边的右行走滑活动断裂组成。野外的实际调查与图像分析的结果十分吻合 ,表明遥感图像在研究活动构造方面是一个十分有力和快速的工具。活动断层的最大水平位移为 2 10m ,最大垂直位移为 2 0m ,主要以走滑作用为主。天山地区活动构造的发育表明印度板块向欧亚板块的碰撞仍在持续     

活动断层填图中的航片解译问题

遥感技术和高精度遥感信息的进步,极大地推动了活动构造和地震地质研究的发展,各种遥感技术在最近几年活动断层填图工作中得到了广泛的应用.如何充分利用各种遥感技术,充分挖掘各种遥感信息以提高填图工作的效率和精度,引起了广大相关科技人员的重视.航空照片以其高精度和高直观性在所有遥感信息源中占据着重要的地位.20世纪中晚期,中国...     

郯庐断裂带中段遥感信息的处理与识别

本文采用数字图象增强处理、数据测定及目视解译等方法,研究郯庐断裂带中段的遥感信息。研究结果是:1.建立了区域活动断裂解译标志,从而得知,本区东部两条主断裂的地面平面展布,南部以右列形式为主,北部主要表现为左列,中部为平行破裂;2.影象上可识别出临沂—郯城地区有四条隐伏的北北东向主断裂及若干条切割主断裂的北西—北西西向断裂。郯庐断裂带中段显示了一些纵向差异性;3.高通滤波处理对本区隐伏构造的影象显示较为有效     

QUANTITATIVE STUDY OF FAULT ACTIVITY BASED ON HIGH-PRECISION AIRBORNE LiDAR DATA: A CASE OF XIAOHONGSHAN FAULT IN XIANGSHAN-TIANJINGSHAN FAULT ZONE

High-precision and high-resolution topography are the basis of quantitative study of active tectonics. Traditional methods are mainly interpreted from the remote sensing image and can only obtain two-dimensional, medium-resolution DEM(5~10m grid unit)or local three-dimensional surface deformation characteristics. A combination of offset and micro-relief information is essential for understanding the long-term rupture pattern of faults, such as in seismic hazard evaluation. The recently developed high-resolution light detection and ranging(LiDAR)technology can directly carry out high-precision and omni-directional three-dimensional measurement of the landform, and provide fine geomorphologic data for the study of active tectonics, which is helpful to deepen the understanding of surface rupture process and fault activity characteristics. In this study, we take part of the Xiaohongshan Fault, the western segment of Xiangshan-Tianjingshan Fault located in Gansu Province(NE Tibet), as an example of how LiDAR data may be used to improve the study of active faults. Using the airborne LiDAR technology, we obtain the three-dimensional surface deformation characteristics with high accuracy and establish the three-dimensional topographic model of the fault geomorphic. A high-resolution digital elevation model(DEM)of the Jingtai-Xiaohongshan Fault was extracted based on high-precision LiDAR data. Then the faulted geomorphic markers(gullies, ridges and terraces)were measured in detail along the fault, and different offset clusters and long-term sliding vector of different segments of the fault were finally acquired. We obtained the 82 horizontal displacements and 62 vertical displacements of geomorphic markers. According to the offset amounts, we observed peaks in the histogram by using the method of cumulative offset probability density and interpreted that each peak may represent an earthquake that ruptured the Xiaohongshan Fault. The results show that the horizontal and vertical displacements fall into five clusters, and the smallest cluster may indicate the coseismic slip of the most recent earthquake, while the other clusters may represent the slip accumulation of multiple preceding earthquakes. The sliding vectors constrained by the horizontal and vertical displacement of several typical geomorphic markers show obvious differences on different segments of the fault. The results show that the fault segment is divided into three segments from west to east, which indicates that the fault activity is not uniform along the fault.     

活动断裂调查中的高分辨率遥感技术应用方法研究

本文系统分析了高分辨率遥感在活动断裂调查中应用的技术现状、工作流程,梳理了各类遥感数据的要求、适用条件和处理方法,总结了活动断裂的遥感解译方法、解译要素和测量参数,并通过实例解析了一些典型的断错地貌,给出了相应的遥感特征. 基于资源三号卫星的立体像对和影像,判读了大青山活动断裂的几何特征和活动特性. 结果表明: 人工改造较大的地区宜收集早期遥感影像,利用不同波段间地物光谱的差异来增强隐伏活动断裂的信息,使用空间增强方法来识别断层陡坎等线性构造;雷达数据多极化分解是检测隐伏构造信息的有效方法;由宏观信息向局部信息追踪是活动断裂解译的有效途径;将遥感影像与数字高程模型(DEM)联合可进行活动断层参数的高精度测量. 本文结果可为活动断裂大比例尺、定量调查提供参考.      

新型便携式行业级无人机精灵4RTK定位精度分析

本文针对新型便携式行业级无人机精灵4RTK开展了实测数据的定位精度分析,从有、无控制点情况下的绝对定位精度和无控制点情况下的相对定位精度2方面入手,详细计算后者水平距离和高程差的测量误差,探讨网络RTK技术的无控制点情况在活动构造中的应用。结果表明,无人机精灵4RTK在天气较晴朗、飞行高度100 m、镜头角度正射向下、旁向和航向重叠率均为70%等实测条件下,有控制点情况下水平位置和高程测量误差均<4.5 cm,无控制点情况下水平位置测量误差<0.60 m、高程测量误差<1.90 m;无控制点情况下,当实际水平距离<300 m时,水平距离测量误差<0.100 m,当高程差<2.8 m时,高程差测量误差<0.100 m;以复合运动性质的发震断层为例,初步探讨认为无人机精灵4RTK的网络RTK技术在无控制点情况下提取活动构造的定量参数时,其水平位移量精度能够达到厘米级,垂直位错量精度可能达不到厘米级,当垂直位错量小于8.0 m时,精度能够达到0.157 m。     

航磁资料在工程场地区域稳定性研究中的应用

本以南北构造带北段区域内一火电厂工程场地为例，利用航磁资料进行反演所得到的磁场异常结果，对深部地质结构特别是隐伏活动断裂的存在进行了分析研究．对航磁资料在区域稳定性研究中的实际应用进行了探讨．     

地震危险区的边界划分探讨

本文针对目前地震危险区边界划分上存在的问题,从地震地质和地震构造的角度,结合测震学方法进行了分析,指出地震分布和地震危险区边界划定与活动构造有密切的联系。依据这一思想,阐明了构造活动与地震活动的关系,初步提出了地震危险区边界判析的原则,即把地震危险区限制在一定的地震构造区(带);其边界依据活动构造划定;在地震危险区内部进行发震构造条件研究,并对这些发震构造(活断层)进行活动度分析;分层次地对地震危险区范围及其危险度进行确定。 本文着重进行了活动构造的研究,对中国大陆的活断层、新生代盆地、地形面以及古地震等作了活动时代、活动性质、活动强度等多方面的论述。     

遥感影像信息在活动断裂研究中的应用

遥感图像不仅从宏观上展现了活动断裂与其它活动构造的影像全貌，而且直观地揭示了洗断裂的影像信息，为分析断裂的活动状态及其与地震活动的相关性，为识别地震构造与强震的孕育地段提供了丰富的信息。而遥感技术方法本身的优势，又使得遥感构造研究具有了视域开阔、信息丰富直观、处理方法多样、易于综合分析、获取成果迅速等特点。从直观上讲，活动断裂遥感影像标志主要有色调、构造形态、断层三角面、地貌及水系等几个方面，归纳起来主要是垂直错动标志。从多方面总结了活动断裂在遥感影像上的表现特征和识别标志，并为今后活动断裂以及地震研究中遥感影像信息的应用提出了一些有效方法和途径。