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1.
水文是沼泽形成、发育和演化的决定性因素。目前,沼泽水位的监测仍然以实地观测为主,需要花费大量的人力和物力。以洪河国家级自然保护区为研究区,利用2007年6~10月星载相控阵L波段合成孔径雷达(phase array type L-band synthetic aperture radar,L-band PALSAR)数据和2015年6~11月C波段Sentinel-1A合成孔径雷达(synthetic aperture radar,SAR)数据,采用合成孔径雷达差分干涉测量(differential interferometric synthetic aperture radar,DInSAR)技术,提取出研究区沼泽的地表形变相位,计算出研究区沼泽水位相对变化量,构建了研究区沼泽水位相对变化量遥感监测经验估算公式,实现了对研究区沼泽年内水位变化量的遥感监测,研究了不同时相浅水沼泽区和深水沼泽区干涉相干性的差异;采用方差分析和回归分析方法,在水位观测站、浅水沼泽区和深水沼泽区3种尺度上,分别对利用两种数据计算出的沼泽水位相对变化量,进行了精度验证和显著性检验。研究结果表明,植物生长期和植物空间格局都对沼泽干涉相干性产生影响,8~10月研究区干涉相干性要好于6~7月,浅水沼泽区干涉相干性要高于深水沼泽区,前者的干涉相干系数比后者的大10%~35%;计算出的沼泽水位相对变化量与地面实测的水位变化量的变化趋势吻合度较高,2007年6~7月和9~10月浅水沼泽区的水位波动幅度较大,水位变化量超过了0.70 m。 相似文献
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鄱阳湖湿地水位与洲滩淹露模型构建 总被引：5，自引：1，他引：4
水是控制湿地生态过程的一个重要因子,为了研究洲滩变化和湿地草洲生长发育规律,以便更好地监测和保护湿地生态系统,有必要研究鄱阳湖水体变化特征,分析湿地洲滩水位的时空动态变化和洲滩淹露规律。本文以鄱阳湖国家级自然保护区为例,在对鄱阳湖多年水位进行分析的基础上,利用多时相遥感影像和DEM提取湿地洲滩特征;并在GIS支持下综合考虑地形、鄱阳湖水位、湖泊缓冲区等因素,建立了湿地水位及洲滩淹露模型。时空验证结果表明,该模型具有较好的模拟效果,精度在85%以上。同时,本文根据研究区特点及水体在TM2、7波段的特征差异,构建了一个新的水体指数FDWI,提取水体精度达到98%,特别是对潮湿的沙地、植被和云有很好的区分能力。 相似文献
3.
《地理与地理信息科学》2020,(3)
正地表变形监测在预防相关地质灾害(如地震、滑坡、地面沉降、火山爆发等),减小地质灾害社会、经济损失中发挥重要作用。差分干涉合成孔径雷达技术(Differential Interferometry Synthetic Aperture Radar,DInSAR)或永久散射体干涉测量技术(Persistent Scatterer Interferometry,PSI)能以较高空间分辨率高效地获取地表形变,且不受日照和天气影响。此外,由于SAR系统使用较短波长微波(3～25cm)对地观测,PSI技术基于SAR影像相位进行地表形变监测的精度可达毫米级。高效、高分辨率、高精度、全天候、全天时、无接触等特点,使得PSI技术在地表形变监测领域具有不可替代的优势。 相似文献
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基于D-InSAR的煤矿区开采沉陷遥感监测技术分析 总被引：10，自引：0，他引：10
该文在综合分析国内外开采沉陷监测技术现状、合成孔径雷达干涉测量(InSAR)和差分干涉测量(D-In SAR)技术发展及其在地表沉陷监测中应用成果的基础上,分析了D-InSAR技术在煤矿开采沉陷变形监测中的特点与技术优势。指出:应用D-InSAR进行煤矿区开采沉陷监测的具体目标是矿区地表沉降演变过程分析、采区地表沉陷动态监测与分析和矿区DEM数据更新;亟须研究解决的关键技术问题有:源数据获取与选择、数据处理方法、地面配合措施、精度与可靠性评价、多源信息集成分析等。D-InSAR为煤矿区地表时空演变过程研究和开采沉陷实时动态监测提供了新的技术方法;作为"数字矿山"的重要内容,D-InSAR可以有效地指导矿区生产、整体规划与长远发展,并为矿区可持续发展服务。 相似文献
7.
基于D—InSAR的煤矿区开采沉陷遥感监测技术分析 总被引：3，自引：0，他引：3
该文在综合分析国内外开采沉陷监测技术现状、合成孔径雷达干涉测量(InSAR)和差分干涉测量(D—InSAR)技术发展及其在地表沉陷监测中应用成果的基础上，分析了D—InSAR技术在煤矿开采沉陷变形监测中的特点与技术优势。指出：应用D—InSAR进行煤矿区开采沉陷监测的具体目标是矿区地表沉降演变过程分析、采区地表沉陷动态监测与分析和矿区DEM数据更新；亟须研究解决的关键技术问题有：源数据获取与选择、数据处理方法、地面配合措施、精度与可靠性评价、多源信息集成分析等。D—InSAR为煤矿区地表时空演变过程研究和开采沉陷实时动态监测提供了新的技术方法；作为“数字矿山”的重要内容，D—InSAR可以有效地指导矿区生产、整体规划与长远发展，并为矿区可持续发展服务。 相似文献
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扎龙湿地水体遥感提取过程中云阴影去除方法研究 总被引：2，自引：1，他引：1
以扎龙湿地为研究区,利用空间分辨率高、纹理信息丰富、定位精度高和购买价格相对低廉的ALOS遥感影像,测定了研究区水体等5种典型地物和云阴影的波谱亮度值;根据水体和云阴影的光谱特征,利用阈值法对近红外波段ALOS影像进行阈值处理,将包含云阴影信息的水体信息提取出来;基于ALOS彩色影像,再采用决策树方法自动提取湿地水体信息,同时将云阴影信息去除,并再补充提取因去除云阴影而损失的水体信息;与目视解译结果相比,用本研究方法得到的研究区湿地水体信息精度高于85%。近红外波段阈值法和彩色影像决策树法相结合的方法是一种能有效去除云阴影而高精度获取湿地水体信息的方法。 相似文献
9.
洞庭湖湿地的面积变化与演替 总被引：46，自引：7，他引：39
洞庭湖湿地是一个与长江相连通的大型内陆淡水湿地,它具有复杂多样的功能和多方面的价值。本文利用遥感与地理信息系统技术对多时相的遥感卫星影像进行处理,获取不同年份、不同季节的洞庭湖湿地类型面积,结合多种文献资料,研究1949年以后洞庭湖湿地面积的季节变化与年际变化,以及近期湿地演替的规律。此外,讨论了影响湿地的面积变化与演替的几个重要因素。使得人民能较全面的地了解洞庭湖湿地,有利于合理地开发利用并保护湿地资源。 相似文献
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《资源与生态学报(英文版)》2016,(2)
成功的生态系统的监测取决于准确的分类结果。本文试图对沼泽湿地的生态特征进行监测。遥感分类常被用于描述生态系统或土地覆盖的格局情况。不同空间分辨率的的遥感影像反映的景观类型,景观特征均存在差异。本文利用不同空间分辨率的遥感影像,对洪河自然保护区湿地生态系统在群落尺度上进行监测。洪河湿地自然保护区是典型的内陆原始沼泽湿地生态系统的保护地,以草本沼泽植被和水生植被为主。根据SPOT-5不同分辨率10 m×10 m、20 m×20 m、30 m×30 m的影像,以及30 m空间分辨率的Landsat TM影像,利用最大似然法(MLC)对洪河保护区进行分类。为了验证分类结果的精度,本文利用航空影像分类数据作为样本,对SPOT-5和TM分类结果进行KAPPA精度验证。由分类结果,得出以下结论:(1)分类结果验证数据对结果的影响很重要;(2)不同传感器的影像对地面生态系统的表达内容不一样,即使是处于相同的光谱波段,同一空间分辨率的情况下。分类结果不仅取决于生态系统类型的多样性和斑块形状,还取决于面积维数和斑块的聚合度。(3)洪河自然保护区核心区湿地保护最好,其次是缓冲区,最差的是实验区。实验区已经有大面积的湿地被人类开垦成农田,湿地生态系统已经退化的很严重。因此,对珍稀生态系统的保护应该与人类的活动区强制的隔离开,才能保护原始湿地生态系统多样性。 相似文献
11.
On the application of SAR interferometry to geomorphological studies: estimation of landform attributes and mass movements 总被引：9，自引：0，他引：9
Filippo Catani Paolo Farina Sandro Moretti Giovanni Nico Tazio Strozzi 《Geomorphology》2005,66(1-4):119
This paper presents two examples of application of Synthetic Aperture Radar (SAR) interferometry (InSAR) to typical geomorphological problems. The principles of InSAR are introduced, taking care to clarify the limits and the potential of this technique for geomorphological studies. The application of InSAR to the quantification of landform attributes such as the slope and to the estimation of landform variations is investigated. Two case studies are presented. A first case study focuses on the problem of measuring landform attributes by interferometric SAR data. The interferometric result is compared with the corresponding one obtained by a Digital Elevation Model (DEM). In the second case study, the use of InSAR for the estimation of landform variations caused by a landslide is detailed. 相似文献
12.
近年来,合成孔径雷达干涉测量（InSAR）技术应用于地表沉降监测研究领域的方法与实例在国内外工程实践和科研活动中经常出现。近几十年来由于地下水的长期超量开采,华北平原已成为世界上超采地下水最严重、地下水降落漏斗面积最大、地面沉降面积最大、沉降类型最复杂的地区,地表沉降监测周期长、成本高、数据量大,通过In SAR技术的应用可有效提高地表沉降观测的精确性,为预防和减少经济损失发挥积极重要作用。 相似文献
13.
海岸线是海洋与陆地的交界线,全球气候变化将引起海岸线的变迁,极地区域拥有最大的冰川,冰川的消融将导致全球海岸线的迅速变迁,因此研究极地海岸线具有重要的科学意义。由于潮汐等影响,卫星影像提取的海洋与陆地的交界线只是海岸水边线,本文以格陵兰岛海岸为实验对象,采用Gamma滤波方法对合成孔径雷达(SAR)数据的相干斑进行预处理,提出了应用支持向量机(SVM)和Canny边缘检测算子的海岸水边线提取方法,基于Terra SARX影像的实验结果表明,本文提取的格陵兰海岸水边线准确率都达60%以上。 相似文献
14.
EnviSat ASAR数据在水情监测中的应用 总被引：6，自引：0，他引：6
在微波遥感领域,星载雷达是目前获取地球信息最主要的技术手段之一,而欧空局EnviSat卫星上搭载的先进合成孔径雷达ASAR是目前功能最为强大的星载雷达系统。以ASAR作为数据源,通过分析入射角、极化方式等因素对水体后向散射特性的影响,提出遥感水情监测中对ASAR数据产品的选取原则。根据水体在雷达图像数据中具有较低值的特点,使用阈值法识别水体。结果表明,使用H/H极化或V/H极化方式的数据都可以比较准确地提取水体信息。 相似文献
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InSAR技术在地形测量和地质灾害研究中的应用 总被引：5，自引：1，他引：5
合成孔径雷达干涉测量技术为地形测量和地质灾害的研究提供了一个全新的工具。如果在获取两景雷达图像的间隔期间地面发生了变形(比如地面沉降、滑坡、火山活动等)，运用InSAR技术可以得到亚厘米级精度的地面位移图。本文作者向工程地质学家简略介绍了InSAR技术的基本原理以及一些实际地质应用，这些实例说明了InSAR技术在地形测量和地质灾害研究中具有独特的能力。 相似文献
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Classification is an important process in interpretation of synthetic aperture radar(SAR) imagery. As an advanced instrument for remote sensing, the polarimetric SAR has been applied widely in many fields. The main aim of this paper is to explore the ability of the full-polarization SAR data in classification. The study area is a part of Dunhuang, Gansu Province, China. An L-band full-polarization image of Dunhuang which includes quad-polarization modes was acquired by the ALOS-PALSAR(Advanced Land Observing Satellite–the Phased Array type L-band Synthetic Aperture Radar). Firstly, new characteristic information was extracted by the difference operation, ratio operation, and principal component transform based on the full-polarization(HH, HV or VH, VV) modes SAR data. Then the single-, dual-, full-polarization SAR data and new SAR characteristic information were used to analyze quantitatively the classification accuracy based on the Support Vector Machines(SVM). The results show that classification overall accuracy of single-polarization SAR data is poor, and the highest is 56.53% of VV polarization. The classification overall accuracy of dual-polarization SAR is much better than single-polarization, the highest is 74.77% of HV VV polarization data. The classification overall accuracy of full-polarization SAR is 80.21%, adding the difference characteristic information, ratio characteristic information and the first principal component(PC1) respectively, the overall accuracy increased by 3.09%, 3.38%, 4.14% respectively. When the full-polarization SAR data in combination with the all characteristic information, the classification overall accuracy reached to 91.01%. The full-polarization SAR data in combination with the band math characteristic information or the PC1 can greatly improve classification accuracy. 相似文献
17.
ZhenMing Wu Lin Zhao Lin Liu Rui Zhu ZeShen Gao YongPing Qiao LiMing Tian HuaYun Zhou MeiZhen Xie 《寒旱区科学》2018,10(2):114-125
Differential Interferometric Synthetic Aperture Radar(D-In SAR) has been widely used to measure surface deformation over the Tibetan Plateau. However, the accuracy and applicability of the D-In SAR method are not well estimated due to the lack of in-situ validation. In this paper, we mapped the seasonal and long-term displacement of Tanggula(TGL) and Liangdaohe(LDH) permafrost regions with a stack of Sentinel-1 acquisitions using the Small Baseline Subset In SAR(SBAS-In SAR) method. In the TGL region, with its dry soils and sparse vegetation, the In SAR-derived surface-deformation trend was consistent with ground-based leveling results; long-term changes of the active layer showed a settlement rate of around 1 to 3 mm/a due to the melting of ground ice, indicating a degrading permafrost in this area. Around half of the deformation was picked up on monitoring, in contrast with in-situ measurements in LDH, implying that the D-In SAR method remarkably underestimated the surface-deformation. This phenomenon may be induced by the large soil-water content, high vegetation coverage, or a combination of these two factors in this region. This study demonstrates that surface deformation could be mapped accurately for a specific region with Sentinel-1 C-band data, such as in the TGL region.Moreover, although the D-In SAR technology provides an efficient solution for broad surface-deformation monitoring in permafrost regions, it shows a poor performance in the region with high soil-water content and dense vegetation coverage. 相似文献
18.
Fault slip in the 1997 Manyi, Tibet earthquake from linear elastic modelling of InSAR displacements 总被引：4，自引：0，他引：4
Gareth J. Funning Barry Parsons Tim J. Wright 《Geophysical Journal International》2007,169(3):988-1008
The M w 7.6 1997 Manyi earthquake occurred in an area of central northern Tibet where sparse vegetation coverage and a lack of human habitation provide excellent conditions for Interferometric Synthetic Aperture Radar (InSAR) studies. We use coseismic pairs of radar images acquired by the ESA ERS-2 satellite to construct interferograms of the surface displacement field due to the earthquake. The location and extent of the coseismic fault rupture are mapped using a combination of optical satellite imagery, high-resolution digital topography, interferometric correlation and azimuth offset measurements; in so doing, we are able to relate prominent geomorphic features in the fault zone to bends in the fault.
Using elastic dislocation models consistent with this mapped fault trace, we then test a range of fault geometries and slip conditions to find the combination which best explains the InSAR displacements. Our favoured model contains a reversal in fault dip, approximately halfway along its length, occurring at the location of a restraining bend. Slip on this model fault is heterogeneous, with two areas of peak slip of 7 m or greater, and components of dip-slip displacement which vary significantly along-strike. The success of this model in fitting the data implies that an observed asymmetry in the coseismic interferograms can be explained in terms of the local fault geometry, rather than by using non-linear elastic rheologies as suggested by earlier authors. 相似文献
Using elastic dislocation models consistent with this mapped fault trace, we then test a range of fault geometries and slip conditions to find the combination which best explains the InSAR displacements. Our favoured model contains a reversal in fault dip, approximately halfway along its length, occurring at the location of a restraining bend. Slip on this model fault is heterogeneous, with two areas of peak slip of 7 m or greater, and components of dip-slip displacement which vary significantly along-strike. The success of this model in fitting the data implies that an observed asymmetry in the coseismic interferograms can be explained in terms of the local fault geometry, rather than by using non-linear elastic rheologies as suggested by earlier authors. 相似文献
19.
Atif AHMAD WANG Chao TANG Yixian Mubbashra SULTAN Attia FALAK DUAN Wei WANG Jing 《资源与生态学报(英文版)》2022,13(5):826-841
The judicious use and management of natural resources is vital to achieve sustainable development. Land and water are prime natural resources, and their depletion and degradation can lead to serious threats like land subsidence. Land subsidence is a phenomenon of the alteration of elevation at a point on the earth through the sinking of the surface. It occurs when the earth’s surface loses its support. The major causes of land subsidence include groundwater extraction, mining, construction overload, and other similar factors that increase pressure on the surface and eventually subsidize the land. Urban centers with excessive groundwater extraction and infrastructure development are at a high risk of subsidence. Lahore, the second-largest city in Pakistan, is undergoing an enormous increase in population density, uncontrolled urbanization with very large-scale construction projects, and intensive groundwater extraction which are responsible for subsidence directly or indirectly. Therefore, studies on groundwater status and unplanned urban appraisals have seriously urged monitoring of the subsidence in Lahore. Herein, we used freely available Sentinel-1 data for one year (from August 2018 to August 2019), with a high spatial and temporal resolution, to monitor subsidence in Lahore. The data were processed using the SNAP/StaMPS approach for Persistent Scatterer Interferometric Synthetic Aperture Radar (PSI) analysis, which is an advanced InSAR technique. The displacement velocity map from InSAR processing shows a significant land deformation in the area with values ranging from -114 to 15 mm yr-1. Along with the Sentinel-1 data, we also used supplementary data obtained from various government agencies of Pakistan to study the land cover map, transportation network and waterways of Lahore, soil types, population density, and field points for assessing the results and understanding the roles of various factors in the occurrence of uplift or subsidence. A strong correlation was established between subsidence and various parameters such as groundwater extraction and lowering of the water table, soil type variations, land cover changes, surface water channels, and population density. The deformation map confirms the greatest subsidence in the central part of Lahore, while the uplift is observed in the less populated and rural areas situated near Ravi River. The land subsidence and uplift could be attributed to groundwater extraction and recharge through the canal system and the river, respectively. 相似文献
20.
为了更加精准地从合成孔径雷达（SAR）图像中提取水边线,提出基于G0分布的SAR图像水边线提取方法。首先,将SAR图像域划分为大小相等的子块,并假设每个子块内像素强度服从独立同一的G0分布;利用矩估计方法得到对应每个子块的粗糙度和散射性参数;根据设定的参数阈值,可划分出粗略的水域,并确定该区域的几何中心;以该几何中心为圆心,向四周做射线,保留经过陆地区域的射线;利用似然函数确定每条射线上的水-陆分界点,依次连接分界点,进而实现SAR图像水边线提取。采用本文方法,分别对模拟和真实SAR图像进行水边线提取实验。定性和定量结果表明：采用基于G0分布的SAR图像水边线提取方法能够有效地克服斑点噪声的影响。 相似文献