Mapping the Yellow River Delta land subsidence with multitemporal SAR interferometry by exploiting both persistent and distributed scatterers

Yan'an new district (YND) is one of the largest civil engineering projects for land creation in Loess Plateau, of which the amount of earthwork exceeds 600 million m 3 , to create 78.5 km 2 of flat land. Such mega-scale engineering activities and complex geological characteristics have induced wide land deformation in the region. Small baseline subset synthetic aperture radar interferometry (SBAS-InSAR) method and 55 Sentinel-1A (S-1A) images were utilized in the present work to investigate the urban surface deformation in the Yan'an urban area and Yan'an new airport (YNA) from 2015 to 2019. The results were validated by the ground leveling measurements in the YNA. It is found that significant uneven surface deformation existed in both YND and YNA areas with maximum accumulative subsidence of 300 and 217 mm, respectively. Moreover, the average subsidence rate of the YND and YNA areas ranged from −70 to 30 mm/year and −50 to 25 mm/year, respectively. The present work shows that the land deformation suffered two periods (from 2015 to 2017 and from 2017 to 2019) and expanded from urban center to surrounding resettlement area, which are highly relevant with urban earthwork process. It is found that more than 60% of land subsidence occurs at filled areas, while more than 65% of surface uplifting occurs at excavation areas. The present work shows that the subsidence originates from the earth filling and the load of urban buildings, while the release of stress is the major factor for the land uplift. Moreover, it is found that the collapsibility of loess and concentrated precipitation deteriorates the degree of local land subsidence. The deformation discovered by this paper shows that the city may suffer a long period of subsidence, and huge challenges may exist in the period of urban maintaining buildings and infrastructure facilities.The widely applied methods for monitoring urban surface deformation are leveling measurement and global navigation satellite system (GNSS) measurement [17]. These methods can achieve high precision at single points in the monitoring of local land subsidence with low spatial resolution and high cost [18]. On the other hand, synthetic aperture radar interferometry (InSAR) has significant advantages over other methods, including fast surface deformation with large monitoring range, operability in all climatic conditions, low operational cost and high spatial resolution [19]. The first application of the InSAR was the monitoring of an earthquake in Landers, California [20], but the temporal resolution was relatively low because of the absence of analyzing on time series images. To overcome this limitation, multi-temporal InSAR was introduced for long-term and large-scale monitoring of surface deformation [21,22]. More specifically, a permanent scatterers InSAR (PS-InSAR) method proposed by Ferretti et al. and a small baseline subset InSAR (SBAS-InSAR) method introduced by Berardino et al. have been widely used in related fields with millimetric accuracy [23][24][25]. Zhang and Zhou analyzed W...

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confidence: 99%

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confidence: 99%

SBAS-InSAR Based Deformation Detection of Urban Land, Created from Mega-Scale Mountain Excavating and Valley Filling in the Loess Plateau: The Case Study of Yan’an City

Jia

Chen

et al. 2019

“…Instead, we utilize an iteration procedure learned from Guarnieri and Tebaldini [39], which offers high computational efficiency when the approximate, rather than the optimized, solution is to be estimated. We directly use the coherence matrix as the weight factor in the iteration process, i.e., γ m,n is derived from Ĉ [41]. The phase reconstruction strategy is referred as coherence weighted phase link (WPL) hereafter, i.e.,:θ…”

Section: Phase Reconstruction Using Coherence Weighted Phase Link (Wpl)mentioning

confidence: 99%

“…Moreover, instead of searching an optimal solution of DS phases in the phase reconstruction step, we use the efficient iterative phase link algorithm to estimate the approximation solution [39,40]. The coherence matrix was used to replace the original weight coefficient in the phase link procedure [36,41]. This change has further shortened the execution time, as the matrix inversion operation is omitted in the iteration.…”

Section: Introductionmentioning

confidence: 99%

Potential of Using Phase Correlation in Distributed Scatterer InSAR Applied to Built Scenarios

Shi

Lin

et al. 2020

Self Cite

The improved spatial resolution of Synthetic Aperture Radar (SAR) images from newly launched sensors has promoted a more frequent use of distributed scatterer (DS) interferometry (DSI) in urban monitoring, pursuing sufficient and detailed measurements. However, the commonly used statistical methods for homogeneous pixel clustering by exploring amplitude information are firstly, computationally intensive; furthermore, their necessity when applied to high-coherent built scenarios is little discussed in the literature. This paper explores the potential of using phase information for the detection of homogeneous pixels on built surfaces. We propose a simple phase-correlated pixel (PCP) clustering and introduce a coherence-weighted phase link (WPL), i.e., PCPWPL, to pursue a faster processing of interferogram phase denoising. Rather than relying on the statistical tests of amplitude characteristics, we exploit vector correlation in the complex domain to identify PCPs with similar phase observations, thus, avoiding the intensive hypothesis test. A coherence-weighted phase linking is applied for DS phase reconstruction. The estimation of geophysical parameters, e.g., deformation, is completed using an integrated network of persistent scatterers (PS) and DS. Efficiency of the proposed method is fairly illustrated by both synthetic and real data experiments. Pros and cons of the proposed PCPWPL were analyzed with the comparison to a conventional amplitude-based strategy using an X-band CosmoSkyMed dataset. It is demonstrated that the use of phase correlation is sufficient for DS monitoring in built scenarios, with equivalent measurement quantity and cheaper computational cost.

“…A number of recent subsidence studies have taken advantage of the high spatial (~20 m) and temporal (up to 5-day revisit) consistency of the Sentinel-1A and B twin satellite constellation of the European space agency [42], as well as higher-resolution platforms such as COSMO-SkyMed (ASI, Italian Space Agency) and TerraSAR-X (DLR, German Aerospace Centre). Zhang et al [219] developed an InSAR method that exploits both persistent and distributed scatterers to map ground subsidence over the entire Yellow River Delta. They applied their method using 30 ENVISAT/ASAR images (2007-2010) and 49 Sentinel-1A images (2015-2018), and achieved a 15-and 5.1-fold higher measuring point density in mapping land subsidence for the ENVISAT and Sentinel-1A datasets respectively (compared to approaches that only use either persistent or distributed scatterers).…”

Section: Earth Observation Potential For Monitoring Of River Delta Lamentioning

confidence: 99%

Remote Sensing for the Quantification of Land Surface Dynamics in Large River Delta Regions—A Review

Kuenzer

Heimhuber

Huth³

et al. 2019

River deltas and estuaries belong to the most significant coastal landforms on our planet and are usually very densely populated. Nearly 600 million people live in river deltas, benefiting from the large variety of locational advantages and rich resources. Deltas are highly dynamic and vulnerable environments that are exposed to a wide range of natural and manmade threats. Sustainable management of river deltas therefore requires a holistic assessment of historic and recent ongoing changes and the dynamics in settlement sprawl, land cover and land use change, ecosystem development, as well as river and coastline geomorphology, all of which is difficult to achieve solely with traditional land-based surveying techniques. This review paper presents the potential of Earth Observation for analyses and quantification of land surface dynamics in the large river deltas globally, emphasizing the different geo-information products that can be derived from medium resolution, high resolution and highest resolution optical, multispectral, thermal and SAR data. Over 200 journal papers on remote sensing related studies for large river deltas and estuaries have been analyzed and categorized into thematic fields such as river course morphology, coastline changes, erosion and accretion processes, flood and inundation dynamics, regional land cover and land use dynamics, as well as the monitoring of compliance with respect to anthropogenic activity such as industry expansion-related habitat destruction. Additionally, our own exemplary analyses are interwoven into the review to visualize related delta work.