基于SBAS-InSAR鲜水河断裂带及蠕滑型滑坡特征研究

发布时间：2018-06-13 18:27

本文选题：青藏高原 + 短基线集　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：鲜水河断裂带地质构造复杂、新构造运动强烈,断裂带内岩土体结构破碎严重,大型-巨型滑坡极为发育,危害严重。由于可见光和近红外遥感受天气影响较大以及DEM等精度的问题,致使应力应变测量、地震监测、近景摄影测量等目前国际上比较有效的滑坡监测技术不能提供比较精确的滑坡信息,只能提供相对宏观定性的、半定量的监测结果。合成孔径雷达干涉测量技术因为其全天时、全天候、能够到达人员难以进入区域、对地面变形监测精度可达到毫米级等优点,近年来在滑坡体识别及形变监测方面得到了广泛应用。因此,本文采用日本的对地观测卫星(ALOS)所获得的PalSAR数据,以鲜水河断裂的地质灾害效应为主要内容,应用时间序列InSAR技术SBAS-InSAR(Small Baseline Subset,InSAR)对蠕滑型滑坡体进行识别并进行缓慢形变监测,对鲜水河断裂带道孚到炉霍段沿线城镇地表蠕滑特征开展位移量分析、滑坡边界识别和稳定性判别分析,取得了以下几点认识:(1)通过对鲜水河断裂6条剖面上像元速率进行统计分析,在置信度为95%时得到鲜水河断裂带2007年到2011年间两侧的相对形变速率约9.40±0.78mm/yr。(2)总体上,对鲜水河断裂带进行2007-2011年InSAR技术地表形变监测:解译出鲜水河断裂带道孚至炉霍段共发育有蠕滑型斜坡108个,且北西段多于南东段,结合InSAR分析、高分辨率遥感影解译像与野外现场调查,这与断裂带北西段北东侧走滑速率大,岩土体破碎严重,强震活动频度高紧密相关。(3)解译出来的滑坡在断裂交汇处尤为发育,这与现场调查的在断裂交汇处岩体破碎较严重,受力方向多样化,交切关系较复杂相一致;滑坡的发生和距鲜水河断裂的距离有很大的关系,解译出来的80%的滑坡发生在断层迹线3km的范围内,这个范围与理论预测和鲜水河断裂破坏区表层破坏程度的实地测量相适应。(4)局部上,在鲜水河断裂两侧选取4处典型的滑坡体(群),对滑坡体位移和速率的时空变化规律进行分析。对于单个滑坡体,其前缘、后缘和中部由于人类活动、小型崩塌、河流冲刷侵蚀等表现出滑动速率不一致。蠕滑型滑坡发生蠕滑的位置主要集中分布在断裂的两侧,在河流侵蚀、岩体破碎、断裂交汇的地方尤为发育。
[Abstract]:The Xianshuihe fault zone is characterized by complex geological structure, strong neotectonic movement, serious breakup of rock and soil structure in the fault zone, extremely development of large-scale giant landslide and serious harm. Because of the great influence of visible light and near infrared remote sensing weather and the accuracy of Dem, the stress and strain measurement and seismic monitoring are caused. The current international landslide monitoring techniques, such as close-range photogrammetry, can not provide accurate landslide information, but can only provide relatively macroscopic qualitative and semi-quantitative monitoring results. Synthetic Aperture Radar (SAR) interferometry technology has the advantages of all-weather, all-day, all-weather access to the area where people are difficult to enter, and the accuracy of monitoring ground deformation can reach millimeter level, etc. In recent years, it has been widely used in landslide body identification and deformation monitoring. Therefore, the PalSAR data obtained from Japan's Earth observation Satellite (ALOS) are used in this paper. Taking the geological hazard effect of Xianshui River fault as the main content, the time series InSAR technology SBAS-InSAR small baseline Subset InSAR is used to identify the creeping landslide and to monitor its slow deformation. In this paper, displacement analysis, landslide boundary identification and stability discriminant analysis are carried out on the surface creep characteristics of towns along Daofu to Luoho section of Xianshuihe fault zone. Through the statistical analysis of pixel rates in 6 sections of the Xianshuihe fault, the relative deformation rate on both sides of the Xianshuihe fault zone between 2007 and 2011 is obtained when the confidence degree is 95. The relative deformation rate on both sides is about 9.40 卤0.78mm / yr.f.) in general, the relative deformation rate of the Xianshuihe fault zone between 2007 and 2011 is obtained. Surface deformation monitoring with InSAR technique in Xianshuihe fault zone from 2007 to 2011 is carried out: 108 creeping slopes developed from Daofu to Luho section of Xianshuihe fault zone, and the north west section is more than the south east part. The InSAR analysis is used to analyze the surface deformation of Xianshuihe fault zone. High-resolution remote sensing image interpretation and field investigation show that the landslide interpreted in the north and west segment of the fault zone has a large strike-slip rate, serious rock and soil fragmentation, and high frequency of strong earthquake activity.) the landslide is particularly developed at the junction of the faults. This is consistent with the fact that the rock mass at the intersection of the faults is broken seriously, the direction of force is diversified and the intersecting relationship is more complicated, and the occurrence of landslide is related to the distance from Xianshuihe fault. The interpreted 80% of the landslides occurred within the range of fault trace 3km, which corresponds to the theoretical prediction and the field measurements of the surface damage degree of the Xianshuihe fault area. Four typical landslide bodies were selected on both sides of Xianshuihe fault to analyze the temporal and spatial variation of displacement and velocity of landslide body. For a single landslide, the slip rates of the front, rear and middle of the landslide are inconsistent due to human activities, small collapses and river erosion. The position of creeping landslide is mainly distributed on both sides of the fault, especially where the river erosion, rock mass breakage and fracture meet.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.22;P542.3

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