【作者】 宫会玲；

【导师】 冉勇康；

【作者基本信息】 中国地震局地质研究所 ， 构造地质学， 2009， 硕士

【摘要】 GIS的发展,促进了地学研究从定性研究向半定量定量化方向的发展。应用地貌理论进行活动构造研究是一种比较成熟、传统的方法。地形分析是地貌研究的重要手段,数字地形分析(Digital Terrain Analysis, DTA)是在数字高程模型DEM上进行地形属性计算和特征提取的数字地形信息处理技术,是DEM应用范围的拓广和延伸。本文基于DTA技术进行安宁河断裂带构造地貌的定量研究并对其垂直位错进行宏观上的分析。安宁河断裂位于青藏高原东缘、横断山脉中段的东部,构造上属扬子地台西缘的康滇台背斜,是南北向构造带的主干断裂之一,是晚第四纪以来活动较为强烈的活动块体边界断裂带.它北接鲜水河活动断裂,南接则木河活动断裂,东邻大凉山断裂,是川滇活动块体的东边界的中部,具有承上启下的作用。文中利用spot立体像对提取DEM和正射影像,以安宁河为研究区,采用检查点法对DEM进行精度评价,算出RMSE为15.64m,符合精度要求。利用高差阴影法识别断层,基于类似恢复古地貌面的原理,得到了研究区最大阶地面(古阶地面),在此基础上进行断层两侧的趋势面分析,宏观上来分析断层逆冲作用引起的地形的改变,同时对一些垂直位错表现明显的断层,做垂直于断层方向的剖面组,剖面线间隔50m,以更细致的去识别断层垂直位错量。由断层两侧的趋势面分析得到的断层面两侧的垂直位错最大值为43m,最小值为3m,平均位错大致为20-5m,而由垂直于断层方向的剖面组得到的位错量最大值为35m,最小值为1m。微观地形地貌形态的划分是宏观地形地貌形态划分的延续和深化,是获取局部专题地形信息的手段之一,文中归纳总结了微观地形地貌形态划分方法。最后通过试验分别对安宁河北段的紫马跨区和南段的泸沽至西昌区的阶地地貌进行划分。紫马跨地区进行阶地划分和变形分析,得到过断裂次级冲沟阶地同步位错,并与实测结果进行对比,,得到了三级阶地形成以来安宁河断裂的左旋位错应为85.4±2m,与全站仪实测位移量基本一致,相差约2米,有较好的一致性。基于DEM对安宁河南端泸沽至西昌地区的阶地进行提取和统计分析,可知安宁河两侧阶地分布明显不对称,位于同一段的河流阶地,东侧同级阶地高度大于西侧,安宁河东侧阶地坡度分布要大于西侧,河谷东西两侧阶地坡向有很大差异,河谷东侧各级阶地总体坡向为南-南西方向,而西侧各级阶地总体坡向为北-北东方向。综上可知安宁河东岸主要表现为以上升为主的构造运动,上升运动的幅度由北向南变缓,河谷两岸阶地的不对称发育,表明了这些阶地主要为构造成因阶地,而东岸的多级阶地也表明了多期的构造抬升。基于DEM和正射影像对安宁河南段的整体区域地貌和微构造地貌的变形进行分析(主要包括冲沟水平位错),冲沟水平位错量从上百米到几十米不等,表明了强烈隆升背景上断块间的差异运动,以及安宁河活动断裂所具有的左旋走滑兼挤压和局部张性特征。更多还原

【Abstract】 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更多还原