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1.
卓冠晨  戴可人  周福军  沈月  陈晨  许强 《地球科学》2022,47(6):2031-2047
为了探明川藏交通廊道典型工点高陡岸坡的稳定性,以及明确SAR(synthetic aperture radar)几何畸变对InSAR(interferometric synthetic aperture radar)形变结果的影响,利用时序InSAR技术开展川藏交通廊道典型工点高陡岸坡形变监测,并提出了一种可识别所有几何畸变类型的SAR几何畸变精细判识方法.成功识别出9处不稳定的高陡岸坡,获取了各轨道SAR几何畸变精细识别结果.在精细划分几何畸变的前提下,通过进一步地将几何畸变与形变结果联合分析,首次揭示了各类几何畸变(包括透视收缩、主被动叠掩、主被动阴影)对InSAR形变结果的影响效果.研究明确了InSAR技术在川藏交通廊道高陡山区的应用能力、适用范围以及几何畸变区结果可靠性的判识,可为后续高陡岸坡形变监测、精确解译等研究提供重要参考.   相似文献   

2.
本文综述了遥感卫星合成孔径雷达（SAR）干涉测量及差分干涉测量的基本原理，针对近年来国外InSAR在地面沉降方面的研究成果，重点讨论了D－InSAR在国内大中城市进行地面沉降监测应用的可能性，对SAR数据的获取方法进行了阐述，并对这种方法目前的进展及未来应用前景进行了探讨。  相似文献   

3.
Interferometric synthetic aperture radar (InSAR) analysis is a radar technique for generating large-area maps of ground deformation using differences in the phase of microwaves returning to a satellite. In recent years, high-resolution SAR sensors have been developed that enable small-scale slope deformation to be detected, such as the partial block movement of a landslide. The L-band SAR (PALSAR-2) is mounted on Advanced Land Observing Satellite-2 (ALOS-2), which was launched on 24 Mar. 2014. Its main improvements compared with ALOS are enhanced resolution of as high as 3 m with a high-frequency recurrence period (14 days). Owing to its high resolution and the use of the L-band, PALSAR-2 can obtain reflective data passing through a tree canopy surface, unlike the other synthetic aperture radars. Therefore, the coherence of InSAR in mountainous forest areas is less likely to decrease, making it advantageous for the extraction of slope movement. In this study, to verify the accuracy of InSAR analysis using PALSAR-2 data, we compared the results of InSAR analysis and the measurement of the displacement in a landslide by global navigation satellite system (GNSS) observation. It was found that the average difference between the displacements obtained by InSAR analysis and the field measurements by GNSS was only 15.1 mm in the slant range direction, indicating the high accuracy of InSAR analysis. Many of the areas detected by InSAR analysis corresponded to the locations of surface changes due to landslide activity. Additionally, in the areas detected by InSAR analysis using multiple datasets, the ground changes due to landslide movement were confirmed by site investigation.  相似文献   

4.
INSAR技术在北京来广营地区地面沉降监测中的应用   总被引：1，自引：0，他引：1  
王颖 《城市地质》2011,6(4):57-60
北京市平原地区地面沉降危害日益显著,合成孔径雷达干涉测量（InSAR）具有快速、高精度、周期短等优势,可为城市地面沉降监测提供有效的技术手段。本文选用ENVISAT-1卫星SAR数据监测研究2004-2005年北京来广营地区地面沉降,利用InSAR差分技术得到该地区地面沉降监测结果。  相似文献   

5.
Most applications of Synthetic Aperture Radar (SAR) make only use of the amplitude information in just one image. Interferometric SAR (InSAR) makes use mainly of the phase measurements in two or more SAR images of the same scene, acquired at two different moments and/or at two slightly different locations. By interference of the two images, very small slant-range changes of the same surface can be inferred. These slant-range changes can be related to topography and/or surface deformations. InSAR thus has the potential of mapping centimeter-scale ground displacements over a region many tens of kilometers in size at a resolution of a few meters making it one of the most promising space-geodetic techniques for monitoring Earth's surface deformations. The goal of this paper is to discuss some of the potential new applications of InSAR for the monitoring of deformations, and to show its major limitations. Some potential new applications of InSAR related to surface-change detection including earthquake and crustal studies, the monitoring of volcanoes and anthropogenic effects, and the monitoring of glaciers and ice sheets are presented. The discussion on the limitations of InSAR for surface-change detection focuses on atmospheric perturbations and the problem of temporal decorrelation.  相似文献   

6.
Post-event Interferometric Synthetic Aperture Radar (InSAR) analysis on a stack of 45 C-band SAR images acquired by the ESA Sentinel-1 satellites from 9 October 2014 to 19 June 2017 allowed the identification of a clear precursory deformation signal for the Maoxian landslide (Mao County, Sichuan Province, China). The landslide occurred in the early morning of 24 June 2017 and killed more than 100 people in the village of Xinmo. Sentinel-1 images have been processed through an advanced multi-interferogram analysis capable of maximising the density of measurement points, generating ground deformation maps and displacement time series for an area of 460 km2 straddling the Minjiang River and the Songping Gully. InSAR data clearly show the precursors of the slope failure in the source area of the Maoxian landslide, with a maximum displacement rate detected of 27 mm/year along the line of sight of the satellite. Deformation time series of measurement points identified within the main scarp of the landslide exhibit an acceleration starting from April 2017. A detailed time series analysis leads to the classification of different deformation behaviours. The Fukuzono method for forecasting the time of failure appear to be applicable to the displacement data exhibiting progressive acceleration. Results suggest that satellite radar data, systematically acquired over large areas with short revisiting time, could be used not only as a tool for mapping unstable areas, but also for landslide monitoring, at least for some typologies of sliding phenomena.  相似文献   

7.
河北蔚县是我国华北地区最大的地下采煤区之一,该地区长期存在采矿塌陷灾害,不仅威胁采矿安全,而且严重破坏当地生态环境。本文基于合成孔径雷达干涉（InSAR）这一新型空间对地观测技术,采用61景Sentinel-1A/B干涉宽幅（Interferometric Wide swath,IW）模式数据进行矿区形变观测,获取整个矿区在2017—2018年间的地表形变空间分布特征,并对矿区地表的沉降量级及面积进行详细的统计分析。此外,采用融合多轨道SAR数据的多维形变时序估计方法,对西细庄矿数据进行东西向和垂向的二维形变分解,获取该矿的二维形变时间序列。结果表明:除南留庄井田外,其余三大井田在监测期间均存在不同程度的地面沉陷灾害;整个矿区年沉陷速率超过-10 cm/a的区域达到了2.16 km2;受成像几何影响,不同轨道数据获取的形变结果存在一定差异;西细庄矿以垂向形变为主,伴随明显的东西向水平形变。研究结果为蔚县矿区地面沉陷监测与煤矿安全开采提供数据参考。   相似文献   

8.
The applicability of the Permanent Scatterers Synthetic Aperture Radar Interferometry (PSInSAR) technique for detecting and monitoring ground displacements was tested in the Oltrepo Pavese territory (Northern Italy, southern Lombardia), which could be representative of similar geological contexts in the Italian Apennines. The study area, which extends for almost 1100 km2, is characterized by a complex geological and structural setting and the presence of clay-rich sedimentary formations. These characteristics make the Oltrepo Pavese particularly prone to several geological hazards: shallow and deep landslides, subsidence and swelling/shrinkage of the clayey soils. The PSInSAR technique used in this study overcomes most of the limitations of conventional interferometric approaches by identifying, within the area of interest, a set of “radar benchmarks” (PS), where very precise displacement measurements can be carried out. More than 90,000 PS were identified by processing Synthetic Aperture Radar (SAR) images acquired from 1992 to 2001 by the European Remote Sensing satellites (ERS). The PSInSAR application at a sub-regional scale detected slow ground deformations ranging from + 5 to − 16 mm/year, and resulting from various processes (landslides, swelling/shrinkage of clay soils and water pumping). The PS displacements were analysed by collecting data obtained through geological, geomorphologic field surveys, geotechnical analysis of the soils and the information was integrated within a landslide inventory and the damaged building inventory. Despite the limited number of landslide bodies with PS (7% of the inventoried landslides), the PS data helped to revise the state of activity of several landslides. Furthermore, some previously unknown unstable slopes were detected. Two areas of uplift and two areas of subsidence were identified.  相似文献   

9.
The Campanian Apennines are characterized by the presence of monocline ridges, mainly formed by limestone. During the periods of volcanic activity of the Somma-Vesuvius and Phlegrean Fields, the ridges were mantled with pyroclastic materials in varying thickness. The pyroclastics have been involved in destructive landslides both in historical time and in the recent past (1997, 1998, 1999). The landslides occur following intense and prolonged rainfalls. In some cases, landslides extended up to 4 km into the surrounding lowlands and reached towns, causing severe destruction and over 200 deaths. Generally, the landslides begin as small debris slides that develop into large, shallow debris avalanches or debris flows involving pyroclastic horizons and colluvial soils (0.5–2 m thick) on steep and vegetated slopes, often at the heads of gullies. During motion, the landslide materials eroded vegetation and soils from the slope, so that the moving material volume tended to increase. Then, proceeding towards and beyond the base of the slopes, the phenomena evolved into hyperconcentrated streamflow due to dilution by incorporating water. The results of motion analyses are described. An empirical rheological relationship was used including two principal terms that depend on the total normal stress and on the flow velocity. On this basis, the model has simulated the velocity and duration of debris avalanches and the distribution of the deposits. The selected areas were those of Sarno/Quindici and Cervinara, where a large amount of data is available both on the material properties and geomorphological setting. It was found that the majority of the cases at the two sites can be simulated successfully with only one specific pair of rheologic parameters. This provides the possibility for first-order predictions to be made of the motion of future landslides. Such predictions will be a valuable tool for outlining potential hazard areas and designing remedial measures.  相似文献   

10.
Heavy mining of Jurassic and Carboniferous horizontal coal seams in the Datong coalfield has seriously affected the local geological environment, which is mainly manifested by such geohazards as soil avalanches, landslides, mudflows, surface subsidence, surface cracks, surface solid waste accumulation and surface deformation. More seriously, coal mining causes groundwater to leak. Overpumping of groundwater has resulted in substantial land subsidence of the urban area in Datong City. Based on the previous geo-environmental investigation in the work area, the authors used radar remote sensing techniques such as InSAR （synthetic aperture radar interferometry） and D-InSAR （differential synthetic aperture radar interferometry）, supplemented by the optical remote sensing method, for geo-environmental investigation to ascertain the geo-environmental background of the Datong Jurassic and Carboniferous-Permian coalfield and evaluate the effects of the geohazards, thus providing a basis for the geo-environmental protection, geohazard control and prevention, land improvement and optimization of the human environment. In this study 8 cog-nominal ERS-1/2 SAR data frames during 1992 to 2003 were used, but the following processing was made： （1） the multitemporal SAR magnitude images were used to interpret the geological structure, vegetation, microgeomorphology and drainage system; （2） the multi-temporal InSAR coherent images were used to make a classification of surface features and evaluate the coherence change due to coal mining; and （3） the multi-temporal cog-nominal SAR images were used to complete D-InSAR processing to remove the information of differential deformation areas （sites）. In the end, a ten-year time series of differential interferograms were obtained using the multi-temporal cog-nominal SAR images. In the tests, 84 deformed areas （sites） were obtained, belonging to those in 1993-1996, 1996-1997, 1997-1998, 1998-2001, 1998-2002 and 2001-2003 respectively. Of the 84 areas, 44 are m  相似文献   

11.
The Hill Country of Central Texas, USA, is undergoing rapid socioeconomic development, but environmental management of this region is hampered by misconceptions about local bedrock, soils, terrain, and hydrologic processes. The Hill Country is underlain mostly by Glen Rose Limestone (Lower Cretaceous) and exhibits a stepped terrain, which has been incorrectly attributed to alternating hard and soft bedrock strata. Other characteristics mistakenly attributed to this landscape include thin soils with scant water-retention capabilities, and rapid runoff as the dominant hydrologic process. This report presents new findings: unweathered bedrock is well indurated, but interbeds exhibit variable weathering rates. Recessive slopes (“risers”) on this stepped terrain result from rapid deterioration of strata having generally heterogeneous depositional fabrics (bioturbation and irregular clay partings) in contrast to ledge-forming strata having homogeneous fabrics. A stony regolith is thus formed beneath risers, providing porous and permeable ground that retards runoff and promotes the formation of moderately deep to deep (two-tiered) regolith/soil zones. These surficial materials on local steep slopes compose important natural environmental buffers; they support diverse biota and enhanced geochemical cycling of nutrients; they also exhibit significant water retention and enhanced erosion abatement. Proper land management demands recognition of these attributes in the siting, design, and construction of facilities.  相似文献   

12.
Mapping of micro topography using airborne laser scanning   总被引：2，自引：1，他引：1  
Intense rainfall conditions and seismic activity commonly trigger fluidised landslides which are characterized by rapid movement and long run-out. They are potentially a very dangerous form of landslide phenomena and may result in extensive damage due to their sudden movement. Until now, photogrammetry has been used to produce maps and investigate such landslides in areas where these disasters occur. Recently, however, airborne laser scanning technology has become a promising technique for making topographical maps and investigating the micro topographic details of these landslide disasters, particularly on slopes around urban areas where the potential risk is high. In this study, airborne laser scanning was carried out in the Tama Hills, near Tokyo, Japan, which is extensively affected by this type of landsliding. The effectiveness of this technique was tested and compared with a laser contour map and aerial photograph interpretations.  相似文献   

13.
The 1994 Northridge earthquake (Mw = 6.7) triggered extensive rock slope failures in Pacoima Canyon, immediately north of Los Angeles, California. Pacoima Canyon is a narrow and steep canyon incised in gneissic and granitic rocks. Peak accelerations of nearly 1.6 g were recorded at a ridge that forms the left abutment of Pacoima Dam; peak accelerations at the bottom of the canyon were less than 0.5 g, suggesting the occurrence of topographic amplification. Topographic effects have been previously suggested to explain similarly high ground motions at the site during the 1971 (Mw = 6.7) San Fernando earthquake. Furthermore, high landslide concentrations observed in the area have been attributed to unusually strong ground motions rather than higher susceptibility to sliding compared with nearby zones. We conducted field investigations and slope stability back-analyses to confirm the impact of topographic amplification on the triggering of landslides during the 1994 earthquake. Our results suggest that the observed extensive rock sliding and falling would have not been possible under unamplified seismic conditions, which would have generated a significantly lower number of areas affected by landslides. In contrast, modelling slope stability using amplified ground shaking predicts slope failure distributions matching what occurred in 1994. This observation confirms a significant role for topographic amplification on the triggering of landslides at the site, and emphasises the need to select carefully the inputs for seismic slope stability analyses.  相似文献   

14.
The study was conducted in the rapidly expanding city of Mekelle located in the northern part of Ethiopia, East Africa. An integrated approach including geomorphological, geological and engineering geological, geotechnical and hydrogeological methods were used to characterize the natural urban environment to be used as a baseline for protection and rational planning of development. Conventional field observation, test pits and drilled boreholes were used to collect soil, rock and water samples and standard laboratory procedures were applied. The results revealed that the main geologic constraints to sustainable development of the city are active erosion, instability of slopes, flood hazard, cyclic/alternating hard and weak rock layers, high swelling–shrinkage soils, shallow and unconfined groundwater with variable composition and high susceptibility to corrosion and pollution. It is recommended to avoid development and expansion of the city in areas of steep land forms, at the foot of steep slopes and in areas covered by black alluvial soil deposits. Development of a systematic multidisciplinary database aided by GIS, with continuous monitoring and updating is also highly recommended and will be useful for further refined geotechnical microzonation. It is the authors’ belief that this study highlights the basic constraints and hazards the city is facing, and provides baseline information and awareness to the city planners, decision makers, geo-environmentalists, engineers and the community for future expansion and rehabilitation plans and to tackle the existing hazards.  相似文献   

15.
Ground deformation phenomena affecting the town of Tuzla (Bosnia Herzegovina), as consequence of underground salt deposits exploitation, have been surveyed since 60?years ago. The growing of cavities beneath the town and successive surface deformations have induced several hazard factors such as ground subsidence, deep and shallow fracturing and intense groundwater table oscillations. Fortunately, this processes had no catastrophic consequences such as sinkholes developing. Previous studies analyzed the historical database of topographic and piezometric data and highlighted a cumulative subsidence rate up to 12 meters over a period spanning from the 1956 to the 2003. Fractures arose as obvious result of ground deformation and caused damages and demolitions to thousands of buildings, with almost 15,000 people evacuated. Nowadays, in order to diminish the deformation processes, a strong reduction in brine withdrawal has been introduced by the local authorities. This caused an uplift of the water table which actually makes the spatial pattern of deformation more complex. In fact, in the most urbanized area, the sinking phenomena are now turning into uplift displacements. The presence of such a hazard required an urban vulnerability assessment able to support local authorities in the forthcoming planning procedure. The vulnerability assessment of urban elements over a wide area, potentially affected by deformation phenomena, has been accomplished by an integration between GIS solutions and a multicriteria approach based on ELECTRE-TRI methodology. The vulnerability procedure is able to define a discrete map where the 50?×?50?m width elementary cells report the most vulnerable parts of the town. In particular, the ELECTRE-TRI methodology is used to combine each vulnerable urban element with the others, expressed as vector data in a geographical dataset. The multicriteria approach is performed outside the GIS environment by the ELECTRE-TRI 2.0 package and requires a preliminary rasterization of the used dataset.  相似文献   

16.
The geometric and kinematic characterization of landslides affecting urban areas is a challenging goal that is routinely pursued via geological/geomorphological method and monitoring of ground displacements achieved by geotechnical and, more recently, advanced differential interferometric synthetic aperture radar (A-DInSAR) data. Although the integration of all the above-mentioned methods should be planned a priori to be more effective, datasets resulting from the independent use of these different methods are commonly available, thus making crucial the need for their standardized a posteriori integration. In this regard, the present paper aims to provide a contribution by introducing a procedure that, taking into account the specific limits of geological/geomorphological analyses and deep/surface ground displacement monitoring via geotechnical and A-DInSAR data, allows the a posteriori integration of the results by exploiting their complementarity for landslide characterization. The approach was tested in the urban area of Lungro village (Calabria region, southern Italy), which is characterized by complex geological/geomorphological settings, widespread landslides and peculiar urban fabric. In spite of the different level of information preliminarily available for each landslide as result of the independent use of the three methods, the implementation of the proposed procedure allowed a better understanding and typifying of the geometry and kinematics of 50 landslides. This provided part of the essential background for geotechnical landslide models to be used for slope stability analysis within landslide risk mitigation strategies.  相似文献   

17.
该文详细论述与分析了合成孔径雷达干涉测量（InSAR)的干涉几何特征及InSAR影像之间的相关性特征，着重阐述并分析了影响其地学监测方面的数据质量等相干技术问题，就InSAR开展上海城市地面沉降研究提出了基本思路，对InSAR城市遥感应用的潜在意义进行了分析和讨论。  相似文献   

18.
史绪国  徐金虎  蒋厚军  张路  廖明生 《地球科学》2019,44(12):4284-4292
坡体表面形变是表征坡体稳定性的重要信息,因此,非常有必要对滑坡多发区域进行时序常规变形监测.近年来,星载合成孔径雷达数据由于其覆盖范围大、形变监测精度高的特点,被越来越多的用于山区滑坡识别与探测.首先介绍了联合分布式目标与点目标的时序InSAR方法,并将该方法应用于分析覆盖三峡藕塘滑坡的2007年至2011年的19景ALOS PALSAR数据和2015年至2018年的47景Sentinel-1数据,提取了数据覆盖时间段内的藕塘地区的变形速率.发现相比于2007年至2011年,2015年至2018年新增三处不稳定斜坡.进一步对滑坡的时序变形分析表明,降雨和水位变化是坡体稳定性最大的两个影响因素.实验证明时序InSAR方法可以作为常规形变手段来识别与监测三峡库区等地区潜在的滑坡,为防灾减灾提供支持与依据.   相似文献   

19.
Based on the working principle of satellite radars, the earthquake deformation field measured by interferometric synthetic aperture (InSAR) is the projection of ground displacement associated with the seismogenic fault in the line of sight (LOS) of the satellite. However, LOS projections are complex, and are not only related to the ascending/descending modes and incidence angles of SAR data, but also related to the strike and motion senses of the fault. Even for the same earthquake, the LOS deformation derived from different ascending/descending data can be almost identical in one case, but quite different in another case, which makes the interpretation of InSAR seismic deformation and its comparison with field observations difficult. In this study, we undertook a quantitative analysis of the relationships between LOS observation sensitivity of InSAR and fault strike, fault motion sense, and ascending/descending modes, as well as 3D deformation fields. We studied the features and differences of the LOS deformation fields in different types of earthquakes using ascending/descending modes, with a particularly detailed analysis of the relations for a strike-slip type of earthquake. We also summarized the characteristics of LOS deformation fields of faults with different strikes and optimal observational data modes. Taking the strike-slip Yushu earthquake and the normal Gaize event as examples, we used SAR data of the ascending/descending modes to verify the results of quantitative calculations. These analyses will not only provide a more reasonable interpretation of InSAR seismic deformation fields and but also help understand the differences of seismic deformation fields revealed by data with different observational modes, therefore promoting the application of InSAR technology in seismology.  相似文献   

20.
作为大地测量的一种新兴空间技术,合成孔径雷达干涉（synthetic aperture radar interferometry, InSAR）具有全天时、高精度、大范围和速度快的优点,逐渐被应用于多年冻土区地表形变监测中。通过综述多年冻土形变原理及InSAR监测多年冻土形变的应用实例,研究表明：在气候变暖的背景下,多年冻土区地表年际形变以下沉为主,多年冻土上限附近地下冰含量的大小是影响年际形变量的主要因素;活动层内土壤含水量影响着地表季节形变量的大小,不同类型多年冻土区的地表年际形变量和季节形变量存在着较大的差异。研究还表明,不同波长的SAR产品在不同类型多年冻土区的适用性不同,下垫面特征对利用InSAR获取地表形变量有较大影响,L波段的SAR数据在植被覆盖度较好的区域有更好的效果。由于InSAR的失相干问题,加之目前还缺少长时间、多类型、高频率的实测形变结果作为验证和标校数据,获取准确且连续的大范围形变数据较为困难。针对目前寒区研究需求,布设野外长期观测站点,建立适用于不同多年冻土区的地表形变反演算法,构建具有较高精度和较高时空分辨率的地表形变数据集具有重要的实践和科学意义。  相似文献   

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