scholarly journals MONITORING GROUND SUBSIDENCE IN AREAS COVERED BY DENSE VEGETATION USING TERRASAR-X IMAGES: A CASE STUDY OF HANGZHOU

2016 ◽  
Vol XLI-B7 ◽  
pp. 55-59
Author(s):  
H. A. Wu ◽  
Y. H. Zhang ◽  
G. F. Luo ◽  
Y. K. Kang ◽  
Y. M. Zhu
Keyword(s):  
High Resolution ◽  
Good Accuracy ◽  
Ground Subsidence ◽  
Sar Images ◽  
Dense Vegetation ◽  
The Past ◽  
Rms Error ◽  
Subsidence Monitoring

Hangzhou, the capital of Zhejiang province has suffered serious ground subsidence during the past several decades, due to long term over-exploration of groundwater. In this paper, the time series InSAR technique using high resolution SAR images is investigated for the generation of subsidence maps over Hangzhou region. 29 TerraSAR-X images acquired from May 2012 to Sep 2015 are used. The results show that serious subsidence has mainly taken place in suburban area, including Yuhang district, Xiaoshan district and Binjiang district. 4 subsidence centers are discovered, namely Tangqi town in Yuhang with an average subsiding velocity of -29.6 mm/year, Xintang (-30.7 mm/year) in Xiaoshan, Zhujiaqiao town (-25.6mm/year) in Xiaoshan, and Miaohouwang town (-30.1mm/year) in Binjiang. The urban area is stable and ground rebound even take place in some places. The results are compared with 19 levelling measurements. The RMS error between them is 2.9 mm/year, which demonstrates that the high resolution TerraSAR-X images has good accuracy for subsidence monitoring in the southeast of China, covered by dense vegetation.

scholarly journals MONITORING GROUND SUBSIDENCE IN AREAS COVERED BY DENSE VEGETATION USING TERRASAR-X IMAGES: A CASE STUDY OF HANGZHOU

2016 ◽  
Vol XLI-B7 ◽  
pp. 55-59
Author(s):  
H. A. Wu ◽  
Y. H. Zhang ◽  
G. F. Luo ◽  
Y. K. Kang ◽  
Y. M. Zhu
Keyword(s):  
High Resolution ◽  
Good Accuracy ◽  
Ground Subsidence ◽  
Sar Images ◽  
Dense Vegetation ◽  
The Past ◽  
Rms Error ◽  
Subsidence Monitoring

Hangzhou, the capital of Zhejiang province has suffered serious ground subsidence during the past several decades, due to long term over-exploration of groundwater. In this paper, the time series InSAR technique using high resolution SAR images is investigated for the generation of subsidence maps over Hangzhou region. 29 TerraSAR-X images acquired from May 2012 to Sep 2015 are used. The results show that serious subsidence has mainly taken place in suburban area, including Yuhang district, Xiaoshan district and Binjiang district. 4 subsidence centers are discovered, namely Tangqi town in Yuhang with an average subsiding velocity of -29.6 mm/year, Xintang (-30.7 mm/year) in Xiaoshan, Zhujiaqiao town (-25.6mm/year) in Xiaoshan, and Miaohouwang town (-30.1mm/year) in Binjiang. The urban area is stable and ground rebound even take place in some places. The results are compared with 19 levelling measurements. The RMS error between them is 2.9 mm/year, which demonstrates that the high resolution TerraSAR-X images has good accuracy for subsidence monitoring in the southeast of China, covered by dense vegetation.

scholarly journals Ground subsidence monitoring over Jiaxing region, Zhejiang province from 2006 to 2010 using time series InSAR technique

2015 ◽  
Vol XL-7/W4 ◽  
pp. 181-184
Author(s):  
H. A. Wu ◽  
Y. H. Zhang ◽  
G. F. Luo ◽  
W. H. Mao ◽  
Y. H. Kang ◽  
...  
Keyword(s):  
Time Series ◽  
Standard Deviation ◽  
Good Accuracy ◽  
Zhejiang Province ◽  
Ground Subsidence ◽  
Envisat Asar ◽  
The Past ◽  
Long Time ◽  
Subsidence Monitoring

Because of over-exploration of groundwater for a long time, Jiaxing region, northeast of Zhejiang province has suffering serious ground subsidence during the past several decades. In this paper, we investigate the time series InSAR technique for the generation of subsidence maps over Jiaxing region. 25 ENVISAT ASAR images acquired from Jan 2006 to Aug 2010 are used. The results show that serious subsidence has taken place in Xiuzhou district, Jiashan county, Pinghu county and Haiyan county. 4 subsidence centers, namely Huanggu town in Pinghu, Wangjiangting town in Xiuzhou, Tianning townin Jiashan, and Wuyuan town in Haiyan. 3 obvious subsidence belts are distributed in Jiaxing. Meanwhile in Tongxiang county, Haining county and Nanhu district, there is relatively seldom subsidence. The results are compared with 35 levelling measurements. The standard deviation of the error between the two data is 4.25 mm/year, which demonstrate that time series InSAR technique has good accuracy for subsidence monitoring in Zhejiang province, southeast of China, covered with lots of vegetation and waters.

A methodology for optimizing modeling configuration in the numerical modeling of oil concentrations in underwater blowouts: a North Sea case study

2021 ◽  
Author(s):  
Andrés Martínez
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Modeling ◽  
High Resolution ◽  
North Sea ◽  
Oil And Gas ◽  
Data Bases ◽  
Lagrangian Trajectory ◽  
Number Of Particles

<p><strong>A METHODOLOGY FOR OPTIMIZING MODELING CONFIGURATION IN THE NUMERICAL MODELING OF OIL CONCENTRATIONS IN UNDERWATER BLOWOUTS: A NORTH SEA CASE STUDY</strong></p><p>Andrés Martínez<sup>a,*</sup>, Ana J. Abascal<sup>a</sup>, Andrés García<sup>a</sup>, Beatriz Pérez-Díaz<sup>a</sup>, Germán Aragón<sup>a</sup>, Raúl Medina<sup>a</sup></p><p><sup>a</sup>IHCantabria - Instituto de Hidráulica Ambiental de la Universidad de Cantabria, Avda. Isabel Torres, 15, 39011 Santander, Spain</p><p><sup>* </sup>Corresponding author: [email protected]</p><p>Underwater oil and gas blowouts are not easy to repair. It may take months before the well is finally capped, releasing large amounts of oil into the marine environment. In addition, persistent oils (crude oil, fuel oil, etc.) break up and dissipate slowly, so they often reach the shore before the cleanup is completed, affecting vasts extension of seas-oceans, just as posing a major threat to marine organisms.</p><p>On account of the above, numerical modeling of underwater blowouts demands great computing power. High-resolution, long-term data bases of wind-ocean currents are needed to be able to properly model the trajectory of the spill at both regional (open sea) and local level (coastline), just as to account for temporal variability. Moreover, a large number of particles, just as a high-resolution grid, are unavoidable in order to ensure accurate modeling of oil concentrations, of utmost importance in risk assessment, so that threshold concentrations can be established (threshold concentrations tell you what level of exposure to a compound could harm marine organisms).</p><p>In this study, an innovative methodology has been accomplished for the purpose of optimizing modeling configuration: number of particles and grid resolution, in the modeling of an underwater blowout, with a view to accurately represent oil concentrations, especially when threshold concentrations are considered. In doing so, statistical analyses (dimensionality reduction and clustering techniques), just as numerical modeling, have been applied.</p><p>It is composed of the following partial steps: (i) classification of i representative clusters of forcing patterns (based on PCA and K-means algorithms) from long-term wind-ocean current hindcast data bases, so that forcing variability in the study area is accounted for; (ii) definition of j modeling scenarios, based on key blowout parameters (oil type, flow rate, etc.) and modeling configuration (number of particles and grid resolution); (iii) Lagrangian trajectory modeling of the combination of the i clusters of forcing patterns and the j modeling scenarios; (iv) sensitivity analysis of the Lagrangian trajectory model output: oil concentrations,  to modeling configuration; (v) finally, as a result, the optimal modeling configuration, given a certain underwater blowout (its key parameters), is provided.</p><p>It has been applied to a hypothetical underwater blowout in the North Sea, one of the world’s most active seas in terms of offshore oil and gas exploration and production. A 5,000 cubic meter per day-flow rate oil spill, flowing from the well over a 15-day period, has been modeled (assuming a 31-day period of subsequent drift for a 46-day modeling). Moreover, threshold concentrations of 0.1, 0.25, 1 and 10 grams per square meter have been applied in the sensitivity analysis. The findings of this study stress the importance of modeling configuration in accurate modeling of oil concentrations, in particular if lower threshold concentrations are considered.</p>

scholarly journals My history, your history, our history: Developing meaningful community engagement within historic sites and museums

2018 ◽  
Vol 25 (2) ◽  
pp. 300-321
Author(s):  
Jessica Stroja
Keyword(s):  
Community Engagement ◽  
Community Participation ◽  
Participatory Process ◽  
Historic Sites ◽  
Community Needs ◽  
Sense Of Ownership ◽  
The Past ◽  
Challenges And Opportunities

AbstractVarying models of community engagement provide methods for museums to build valuable relationships with communities. These relationships hold the potential to become ongoing, dynamic opportunities for active community participation and engagement with museums. Nevertheless, the nuances of this engagement continue to remain a unique process that requires delicate balancing of museum obligations and community needs in order to ensure meaningful outcomes are achieved. This article discusses how community engagement can be an active, participatory process for visitors to museums. Research projects that utilise aspects of community-driven engagement models allow museums to encourage a sense of ownership and active participation with the museum. Indeed museums can balance obligations of education and representation of the past with long-term, meaningful community needs via projects that utilise aspects of community-driven engagement models. Using an oral history project at Historic Ormiston House as a case study,1 the article argues that museums and historic sites can encourage ongoing engagement through active community participation in museum projects. While this approach carries both challenges and opportunities for the museum, it opens doors to meaningful and long-term community engagement, allowing visitors to embrace the museum and its stories as active participants rather than as passive consumers.

Monitoring Three Gorge Area Landslide currently movement by Mutilplatform SAR Interferometry

2020 ◽  
Author(s):  
Tao Li ◽  
Yangmao Wen ◽  
Lulu Chen ◽  
Jinge Wang
Keyword(s):  
High Resolution ◽  
Surface Deformation ◽  
Test Site ◽  
Deformation Monitoring ◽  
Sar Interferometry ◽  
Sar Image ◽  
Landslide Area ◽  
Sar Images ◽  
The Past ◽  
Huangtupo Landslide

<p>Three Gorge area landslide hazards developed very fast after the Dam started to impound the water since 2007. There were lots of research literatures concentrated on the Badong Huangtupo Landslide area for the whole city center had to change its position in 2009. Several literatures used Envisat SAR images time series to monitoring the surface deformation from 2008~2010. The results showed good consistent with the water level changes and precipitation.  The high resolution TerraSAR Spotlight images had been used to monitoring the Shuping landslide and Fanjiaping landslide area in Zigui country from 2009~2012,the InSAR results showed good details of the landslide boundary and deformation rate with DInSAR technology.</p><p>This paper studies several landslide area in the Three Gorge by InSAR technology in the past few years, such as Huangtupo, Huanglashi , Daping and  Baiheping landslide area , etc. al . The high resolution SAR images covered Badong and Wushan area have been collected, including the Sentinel-1, TerraSAR, RadarSAT-2, ALOS-2 SAR images. The high resolution topography in those landslide area have been collected both by UAV lidar and high resolution topography map.</p><p>The Huangtupo landslide area changed a lot in the past 3 years with the buildings ruins cleared and red soil covered by the local government. The time series results by Sentinel data in this area shows the big changes but could not derive reasonable deformation results.</p><p>Three Gorges Research Center for Geo-hazards (TGRC) of China University of Geosciences(CUG) built the Badong field test site in Huangtupo landslide area. This test site is composed with a tunnel group and a series of monitoring system including the inside sensors, surface deformation monitoring sensors and so on. In this paper, we mounted several new designed dihedral corner reflectors on the Huangtupo landslide area for high precision deformation monitoring by InSAR. Both the  ascending and the  descending orbit data of RadarSAT-2 high resolution SAR image  and TerraSAR Spotlight images have been collected in this field.</p><p>The preliminary results from those new acquiring SAR data series show that the traditional landslide area such as Huanglashi , Daping, Baiheping are all moving slowly with good coherence in SAR image series.  The poor vegetation coverage in those landslide area helped to get the credible  InSAR results. The high resolution DEM is the critical elements for the DInSAR techniques in those landslide area. The steep  topography in those landslide area distorted the SAR images correspondingly.</p><p>Our results shows that it is possible to use ascending and descending high resolution SAR images to monitor the landslide area with mm level precision, while the vegetation is not so dense. High resolution SAR interferometry helped a lot for the landslide boundary detection and detailed analysis. The lower resolution SAR images such as Sentinel-1 still could provide some deformation results in landslide area, but it need more auxiliary data to interpret the results.</p>

scholarly journals EMPIRICAL STUDY ON ALTERNATIVES FOR SAVING AND INVESTING IN THE POSTPANDEMIC PERIOD. CASE STUDY: ROMANIA

2021 ◽  
Vol S.I. (2) ◽  
pp. 27-40
Author(s):  
Alexandru Mihai Alexandru Mihai ◽  
◽  
Ruxandra DINULESCU ◽  
Florin PUCHEANU ◽  
◽  
...  
Keyword(s):  
Empirical Study ◽  
The Past ◽  
Trading Market ◽  
Before And After ◽  
Double Approach ◽  
Potential Risks ◽  
Potential Strategy ◽  
The Impact

This paper develops investigations in the field of saving and investing techniques related to the impact of the COVID19 pandemic on the Romanian trading market. The study focuses particularly on the alternatives for accumulation of money capital which can lead to a positive long-term return. The research aims to investigate the available current services and opportunities in the Romanian investment market and their returns after the pandemic. Towards this objective, the study presents the past returns for several products and the users potential risks. Furthermore, an investigation is conducted based on the latest statistics whereas different variants of portfolios are presented. Unlike most of the previous studies, this analysis has a double approach: evaluating viable alternatives depending on several characteristics and simultaneously developing a long-term potential strategy that could be used to ensure the financial future of an individual in the period of the outbreak of the COVID19 pandemic. This contribution provides an initial analysis of the saving and investing market of Romania before and after the pandemic.

scholarly journals Novel ultra nanoindentation method with extremely low thermal drift: Principle and experimental results

2009 ◽  
Vol 24 (3) ◽  
pp. 873-882 ◽  
Author(s):  
J. Nohava ◽  
N.X. Randall ◽  
N. Conté
Keyword(s):  
Thin Films ◽  
High Resolution ◽  
Thermal Stabilization ◽  
Maximum Load ◽  
Experimental Results ◽  
Thermal Drift ◽  
The Past ◽  
Short Period ◽  
Low Levels

Despite active development over the past 15 years, contemporary nanoindentation methods still suffer serious drawbacks, particularly long thermal stabilization and thermal drift, which limit the duration of the measurements to only a short period of time. The presented work introduces a novel ultra nanoindentation method that uses loads from the μN range up to 50 mN, is capable of performing long-term stable measurements, and has negligible frame compliance. The method is based on a novel patented design, which uses an active top referencing system. Several materials were used to demonstrate the performance of the method. The measurements with hold at maximum load confirm extremely low levels of instrument thermal drift. The presented Ultra Nanoindentation Tester opens new possibilities for testing thin films and long-term testing, including creep of polymers at high resolution without the need of long thermal stabilization.

The Interplay of American Political Culture and Public Policy: The Sacramento River as a Case Study

1989 ◽  
Vol 1 (1) ◽  
pp. 1-23 ◽  
Author(s):  
Robert Kelley
Keyword(s):  
Political Culture ◽  
Environmental History ◽  
The United States ◽  
Two Dimensions ◽  
American Political Culture ◽  
The Past ◽  
History Of ◽  
National Life

Historians of the United States have learned much in the past twenty years about the history of what is now called its political culture, and about its environmental history.1 These two dimensions of national life, however, are rarely, if ever, looked at together. The result is that we little understand how powerfully environmental policy is influenced not simply by everyday politics—of that we know abundantly—but by the long-term political mentalities of the Democrats and the Republicans, mentalities which originate not in abstract theorizing, but which grow up naturally within the cultural worlds to be found among the distinctive groups of peoples who line up within one party or the other and remain there, generation after generation. What I propose here is to put political culture and natural resource management history together and see what happens.

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