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J Mulas - One of the best experts on this subject based on the ideXlab platform.
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radar interferometry techniques for the study of Ground Subsidence phenomena a review of practical issues through cases in spain
Environmental Earth Sciences, 2014Co-Authors: Roberto Tomas, Gerardo Herrera, J Mulas, Rosana Romero, J Marturia, J J Mallorqui, Juan M Lopezsanchez, Francisco GutierrezAbstract:Subsidence related to multiple natural and human-induced processes affects an increasing number of areas worldwide. Although this phenomenon may involve surface deformation with 3D displacement components, negative vertical movement, either progressive or episodic, tends to dominate. Over the last decades, differential SAR interferometry (DInSAR) has become a very useful remote sensing tool for accurately measuring the spatial and temporal evolution of surface displacements over broad areas. This work discusses the main advantages and limitations of addressing active Subsidence phenomena by means of DInSAR techniques from an end-user point of view. Special attention is paid to the spatial and temporal resolution, the precision of the measurements, and the usefulness of the data. The presented analysis is focused on DInSAR results exploitation of various Ground Subsidence phenomena (Groundwater withdrawal, soil compaction, mining Subsidence, evaporite dissolution Subsidence, and volcanic deformation) with different displacement patterns in a selection of Subsidence areas in Spain. Finally, a cost comparative study is performed for the different techniques applied.
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persistent scatterer interferometry Subsidence data exploitation using spatial tools the vega media of the segura river basin case study
Journal of Hydrology, 2011Co-Authors: Roberto Tomas, Gerardo Herrera, G Cooksley, J MulasAbstract:Summary The aim of this paper is to analyze the Subsidence affecting the Vega Media of the Segura River Basin, using a Persistent Scatterers Interferometry technique (PSI) named Stable Point Network (SPN). This technique is capable of estimating mean deformation velocity maps of the Ground surface and displacement time series from Synthetic Aperture Radar (SAR) images. A dataset acquired between January 2004 and December 2008 from ERS-2 and ENVISAT sensors has been processed measuring maximum Subsidence and uplift rates of −25.6 and 7.54 mm/year respectively for the whole area. These data have been validated against Ground Subsidence measurements and compared with Subsidence triggering and conditioning factors by means of a Geographical Information System (GIS). The spatial analysis shows a good relationship between Subsidence and piezometric level evolution, pumping wells location, river distance, geology, the Arab wall, previously proposed Subsidence predictive model and soil thickness. As a consequence, the paper shows the usefulness and the potential of combining Differential SAR Interferometry (DInSAR) and spatial analysis techniques in order to improve the knowledge of this kind of phenomenon.
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mapping Ground Subsidence induced by aquifer overexploitation using advanced differential sar interferometry vega media of the segura river se spain case study
Remote Sensing of Environment, 2005Co-Authors: Roberto Tomas, Gerardo Herrera, J J Mallorqui, Juan M Lopezsanchez, Yolanda Marquez, Jose Delgado, Pablo Blanco, Monica Martinez, J MulasAbstract:Differential SAR Interferometry (DInSAR) is a remote sensing technique with the well-proven ability to monitor Ground deformations. In this work we have applied an advanced DInSAR technique – the Coherent Pixels Technique (CPT) – , to study Subsidence phenomena due to the excessive pumping of Groundwater in the Vega Media of the Segura River (SE Spain) from 1993 to the present. The settlement map retrieved with DInSAR shows settlement of up to 8 cm at some points of the study area and has been compared with other data provided by Ground instruments to analyse the relationship with Ground deformation. A correlation has been observed between these measurements and the observations from on-site testing of piezometric Groundwater fluctuations and borehole extensometric settlement. However, the distribution of damaged buildings, well points and basements does not show a clear relationship with measured Subsidence values because the occurrence of damage also depends on the structural state of the buildings and the characteristics of their foundations. In addition, the distribution of pumping wells is not indicative of the distribution of the volume of water withdrawal which is the real conditioning factor of piezometric level changes. It can be concluded that the results obtained provide very useful spatial and temporal data about this phenomenon in an urban area at a low cost. The data can be used for forecasting purposes and helps to define zones with future Ground settlement problems if the same conditions are repeated. This technique has also allowed the monitoring of Ground Subsidence in the Vega Media of Segura River for a period (1993–1995) where no instrument information was available.
Saro Lee - One of the best experts on this subject based on the ideXlab platform.
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application of decision tree model for the Ground Subsidence hazard mapping near abandoned underGround coal mines
Journal of Environmental Management, 2013Co-Authors: Saro Lee, Inhye ParkAbstract:Subsidence of Ground caused by underGround mines poses hazards to human life and property. This study analyzed the hazard to Ground Subsidence using factors that can affect Ground Subsidence and a decision tree approach in a geographic information system (GIS). The study area was Taebaek, Gangwon-do, Korea, where many abandoned underGround coal mines exist. Spatial data, topography, geology, and various Ground-engineering data for the Subsidence area were collected and compiled in a database for mapping Ground-Subsidence hazard (GSH). The Subsidence area was randomly split 50/50 for training and validation of the models. A data-mining classification technique was applied to the GSH mapping, and decision trees were constructed using the chi-squared automatic interaction detector (CHAID) and the quick, unbiased, and efficient statistical tree (QUEST) algorithms. The frequency ratio model was also applied to the GSH mapping for comparing with probabilistic model. The resulting GSH maps were validated using area-under-the-curve (AUC) analysis with the Subsidence area data that had not been used for training the model. The highest accuracy was achieved by the decision tree model using CHAID algorithm (94.01%) comparing with QUEST algorithms (90.37%) and frequency ratio model (86.70%). These accuracies are higher than previously reported results for decision tree. Decision tree methods can therefore be used efficiently for GSH analysis and might be widely used for prediction of various spatial events.
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sensitivity analysis for the gis based mapping of the Ground Subsidence hazard near abandoned underGround coal mines
Environmental Earth Sciences, 2011Co-Authors: Seungchan Ahn, Jongkuk Choi, Saro LeeAbstract:Ground Subsidence around abandoned underGround coal mines can cause much loss of life and property. We analyze factors that can affect Ground Subsidence around abandoned mines in Jeongahm in Kangwon-do by sensitivity analysis in geographic information system (GIS). Spatial data for the Subsidence area, topography and geology and various Ground engineering data were collected and used to make a factor raster database for a Ground Subsidence hazard map. To determine the importance of extracted Subsidence-related factors, frequency ratio model and sensitivity analysis were employed. Sensitivity analysis is a method for comparing the combined effects of all factors except one. Sensitivity analysis and its verification showed that using all factors provided 91.61% accuracy. The best accuracy was achieved by not considering the Groundwater depth (92.77%) and the worst by not considering the lineament (85.42%). The results show that the distance from the lineament and the distance from the drift highly affected the occurrence of Ground Subsidence, and the Groundwater depth, land use and rock mass rating had the least effects. Thus, we determined causes of Ground Subsidence in the study area and this information could help in the prediction of Ground Subsidence in other areas.
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integration of Ground Subsidence hazard maps of abandoned coal mines in samcheok korea
International Journal of Coal Geology, 2011Co-Authors: Saro LeeAbstract:Integrated techniques were developed, applied, and validated for the analysis of Ground Subsidence hazards by abandoned coal mines in Samcheok, Korea, using a geographic information system (GIS). Slope, depth of drift, distance from drift, Groundwater level, permeability, geology, and land use were extracted or calculated from the digital elevation model, topographic, drift distribution, borehole, geologic, and land use database. By using the constructed spatial database, the relations between the Ground Subsidence location and seven related factors were identified and quantified by frequency ratio (FR), weights-of-evidence (WOE), logistic regression (LR), and artificial neural network (ANN) models. The relations were used as factor ratings in the overlay analysis to create Ground Subsidence hazard indices and maps. The four Ground Subsidence hazard maps were reflected as the new input factors and integrated using FR, WOE, LR, and ANN models to make a hazard map. All of the Subsidence hazard maps were validated by comparison with known Ground Subsidence locations that were not used in the analysis. As a result, the integrated Ground Subsidence hazard maps used four new Subsidence-related input factors that showed a greater accuracy (96.46% for FR, 97.22% for WOE, 97.20% for LR, and 96.70% for ANN, respectively), than the individual Ground Subsidence maps (95.54% for FR, 94.22% for WOE, 96.89% for LR, and 94.45% for ANN, respectively) using the first seven factors.
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assessment of Ground Subsidence hazard near an abandoned underGround coal mine using gis
Environmental Earth Sciences, 2006Co-Authors: Kidong Kim, Saro Lee, Jongkuk Choi, Joongsun WonAbstract:This study constructs a hazard map for Ground Subsidence around abandoned underGround coal mines (AUCMs) at Samcheok City in Korea using a probability (frequency ratio) model, a statistical (logistic regression) model, and a Geographic Information System (GIS). To evaluate the factors related to Ground Subsidence, an image database was constructed from a topographical map, geological map, mining tunnel map, Global Positioning System (GPS) data, land use map, lineaments, digital elevation model (DEM) data, and borehole data. An attribute database was also constructed from field investigations and reports on the existing Ground Subsidence areas at the study site. Nine major factors causing Ground Subsidence were extracted from the probability analysis of the existing Ground Subsidence area: (1) depth of drift; (2) DEM and slope gradient; (3) Groundwater level, permeability, and rock mass rating (RMR); (4) lineaments and geology; and (5) land use. The frequency ratio and logistic regression models were applied to determine each factor’s rating, and the ratings were overlain for Ground Subsidence hazard mapping. The Ground Subsidence hazard map was then verified and compared with existing Subsidence areas. The verification results showed that the logistic regression model (accuracy of 95.01%) is better in prediction than the frequency ratio model (accuracy of 93.29%). The verification results showed sufficient agreement between the hazard map and the existing data on Ground Subsidence area. Analysis of Ground Subsidence with the frequency ratio and logistic regression models suggests that quantitative analysis of Ground Subsidence near AUCMs is possible.
Roberto Tomas - One of the best experts on this subject based on the ideXlab platform.
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radar interferometry techniques for the study of Ground Subsidence phenomena a review of practical issues through cases in spain
Environmental Earth Sciences, 2014Co-Authors: Roberto Tomas, Gerardo Herrera, J Mulas, Rosana Romero, J Marturia, J J Mallorqui, Juan M Lopezsanchez, Francisco GutierrezAbstract:Subsidence related to multiple natural and human-induced processes affects an increasing number of areas worldwide. Although this phenomenon may involve surface deformation with 3D displacement components, negative vertical movement, either progressive or episodic, tends to dominate. Over the last decades, differential SAR interferometry (DInSAR) has become a very useful remote sensing tool for accurately measuring the spatial and temporal evolution of surface displacements over broad areas. This work discusses the main advantages and limitations of addressing active Subsidence phenomena by means of DInSAR techniques from an end-user point of view. Special attention is paid to the spatial and temporal resolution, the precision of the measurements, and the usefulness of the data. The presented analysis is focused on DInSAR results exploitation of various Ground Subsidence phenomena (Groundwater withdrawal, soil compaction, mining Subsidence, evaporite dissolution Subsidence, and volcanic deformation) with different displacement patterns in a selection of Subsidence areas in Spain. Finally, a cost comparative study is performed for the different techniques applied.
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persistent scatterer interferometry Subsidence data exploitation using spatial tools the vega media of the segura river basin case study
Journal of Hydrology, 2011Co-Authors: Roberto Tomas, Gerardo Herrera, G Cooksley, J MulasAbstract:Summary The aim of this paper is to analyze the Subsidence affecting the Vega Media of the Segura River Basin, using a Persistent Scatterers Interferometry technique (PSI) named Stable Point Network (SPN). This technique is capable of estimating mean deformation velocity maps of the Ground surface and displacement time series from Synthetic Aperture Radar (SAR) images. A dataset acquired between January 2004 and December 2008 from ERS-2 and ENVISAT sensors has been processed measuring maximum Subsidence and uplift rates of −25.6 and 7.54 mm/year respectively for the whole area. These data have been validated against Ground Subsidence measurements and compared with Subsidence triggering and conditioning factors by means of a Geographical Information System (GIS). The spatial analysis shows a good relationship between Subsidence and piezometric level evolution, pumping wells location, river distance, geology, the Arab wall, previously proposed Subsidence predictive model and soil thickness. As a consequence, the paper shows the usefulness and the potential of combining Differential SAR Interferometry (DInSAR) and spatial analysis techniques in order to improve the knowledge of this kind of phenomenon.
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mapping Ground Subsidence induced by aquifer overexploitation using advanced differential sar interferometry vega media of the segura river se spain case study
Remote Sensing of Environment, 2005Co-Authors: Roberto Tomas, Gerardo Herrera, J J Mallorqui, Juan M Lopezsanchez, Yolanda Marquez, Jose Delgado, Pablo Blanco, Monica Martinez, J MulasAbstract:Differential SAR Interferometry (DInSAR) is a remote sensing technique with the well-proven ability to monitor Ground deformations. In this work we have applied an advanced DInSAR technique – the Coherent Pixels Technique (CPT) – , to study Subsidence phenomena due to the excessive pumping of Groundwater in the Vega Media of the Segura River (SE Spain) from 1993 to the present. The settlement map retrieved with DInSAR shows settlement of up to 8 cm at some points of the study area and has been compared with other data provided by Ground instruments to analyse the relationship with Ground deformation. A correlation has been observed between these measurements and the observations from on-site testing of piezometric Groundwater fluctuations and borehole extensometric settlement. However, the distribution of damaged buildings, well points and basements does not show a clear relationship with measured Subsidence values because the occurrence of damage also depends on the structural state of the buildings and the characteristics of their foundations. In addition, the distribution of pumping wells is not indicative of the distribution of the volume of water withdrawal which is the real conditioning factor of piezometric level changes. It can be concluded that the results obtained provide very useful spatial and temporal data about this phenomenon in an urban area at a low cost. The data can be used for forecasting purposes and helps to define zones with future Ground settlement problems if the same conditions are repeated. This technique has also allowed the monitoring of Ground Subsidence in the Vega Media of Segura River for a period (1993–1995) where no instrument information was available.
C Loupasakis - One of the best experts on this subject based on the ideXlab platform.
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Ground Subsidence triggered by the overexploitation of aquifers affecting urban sites the case of athens coastal zone along faliro bay greece
Geofluids, 2020Co-Authors: Agavni Kaitantzian, C Loupasakis, P Tzampoglou, Isaak ParcharidisAbstract:Land Subsidence in the coastal zone of the Neo Faliro, Moschato, and Kallithea municipalities, along the Faliro bay, has been recorded since the mid 1960’s. This phenomenon has caused damage to buildings, pavements, and roads. Aiming to identify the main causes of the observed Ground deformations, data referring to the geological, geotechnical, and hydrogeological settings of the study area has been evaluated. Subsidence has been quantified by the use of space-born Synthetic Aperture Radar interferometry (InSAR) techniques. SVD (Singular Value Decomposition) and IPTA (Interferometric Point Target Analysis) techniques have been applied for the production of deformation maps, referring to the time period between 2002 and 2010. Furthermore, aiming to extend the study of the phenomenon further to the past, Persistent Scatterer Interferometry (PSI) data for the time period from 1992 to 2001 were also evaluated. Finally, the results of the InSAR analysis have been crosschecked with measurements acquired by a vertical geodetic control network as well as by Ground truth data, referring to damage inventory of the site. The current research presents an interesting case study of an urban site affected for a long-lasting period by the activities of a neighboring industrial zone. The development of an extensive depression cone, mainly due to the overexploitation of the aquifers for industrial use, is the main cause of the land Subsidence phenomenon, without excluding a component of motion due to the natural compaction of the compressible soil in the area of interest. The complexity of the geological, hydrogeological, and geotechnical conditions and the interaction of the numerous land use activities make this study far more interesting.
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evaluating geological and geotechnical data for the study of land Subsidence phenomena at the perimeter of the amyntaio coalmine greece
International journal of mining science and technology, 2017Co-Authors: P Tzampoglou, C LoupasakisAbstract:Abstract Land Subsidence phenomena caused by the overexploitation of the aquifers require the holistic knowledge of the geological, tectonic, hydrogeological and especially the geotechnical conditions of the affected sites in order to be mitigated. The current paper focuses on the study of the phenomena taking place at the Amyntaio sub-basin, northern Greece, hosting the homonymous open pit coal mine, operating there the last two decades. The mining as well as the rising agriculture activities have led to a significant drawdown of the Ground water level triggering extensive Ground Subsidence phenomena, causing damages at the nearby villages, infrastructure and farmlands. The production and evaluation of engineering geological–geotechnical maps as well as of thematic tectonic and hydrogeological maps proved that the knowledge of this data is crucial for the interpretation of the land Subsidence mechanism and the spatial distribution of its effects.
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Ground Subsidence phenomena in the delta municipality region northern greece geotechnical modeling and validation with persistent scatterer interferometry
International Journal of Applied Earth Observation and Geoinformation, 2014Co-Authors: Federico Raspini, C Loupasakis, D Rozos, Nico Adam, Sandro MorettiAbstract:Abstract Land Subsidence is a common phenomenon occurring in several regions worldwide. Persistent Subsidence causes strong consequences on the affected areas and related problems include environmental, economic and social aspects. A set of forty-two Synthetic Aperture Radar (SAR) images, acquired in 1995–2001 by the European Space Agency (ESA) satellites ERS1 and ERS2, were processed with Persistent Scatterer Interferometry (PSI) technique to investigate spatial and temporal patterns of deformation in the Delta municipality (Thessaloniki plain, Northern Greece), a deltaic area with a long history of land Subsidence related to aquifer system compaction. Exploitation of output products of a PSI analysis, both average LOS (Line of Sight) deformation rates and displacement time series, revealed a large Subsidence area due to intense Groundwater withdrawal. Higher displacement velocities have been observed south-west of Kalochori and south of Sindos, from both sides of the Gallikos River. In those areas deformation rates of roughly 4.5 cm/yr have been recorded, during the period from 1995 to 2001. Increasing Subsidence rates are measured moving toward the mouth of the Gallikos River, where the thickest sequence of compressible Quaternary sediments is observed. Displacement time series retrieved by PSI technique has been compared with the temporal evolution of the deformation as measured by pre-existing leveling surveys, showing a great agreement. A 2-D finite element model has been run along two representative cross sections in the Kalochori area, in order to simulate the observed temporal evolution of Subsidence, coupling the geotechnical behavior of the formations and the piezometric surface level. Finally, results obtained by the Subsidence model have been positively compared with the PSI-based information on displacement, providing accurate and perfectly verified results. Outcomes of this work demonstrated the potential of repeat-pass satellite SAR interferometry (InSAR) as suitable technique for increasing knowledge about the extent and the rate of the deformations in case of Subsidence events. Moreover, InSAR turned out to be a valuable tool to validate Subsidence models and represents a cost-efficiency method, alternative to Ground-based measurements for investigating surface deformation phenomena.
Gerardo Herrera - One of the best experts on this subject based on the ideXlab platform.
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radar interferometry techniques for the study of Ground Subsidence phenomena a review of practical issues through cases in spain
Environmental Earth Sciences, 2014Co-Authors: Roberto Tomas, Gerardo Herrera, J Mulas, Rosana Romero, J Marturia, J J Mallorqui, Juan M Lopezsanchez, Francisco GutierrezAbstract:Subsidence related to multiple natural and human-induced processes affects an increasing number of areas worldwide. Although this phenomenon may involve surface deformation with 3D displacement components, negative vertical movement, either progressive or episodic, tends to dominate. Over the last decades, differential SAR interferometry (DInSAR) has become a very useful remote sensing tool for accurately measuring the spatial and temporal evolution of surface displacements over broad areas. This work discusses the main advantages and limitations of addressing active Subsidence phenomena by means of DInSAR techniques from an end-user point of view. Special attention is paid to the spatial and temporal resolution, the precision of the measurements, and the usefulness of the data. The presented analysis is focused on DInSAR results exploitation of various Ground Subsidence phenomena (Groundwater withdrawal, soil compaction, mining Subsidence, evaporite dissolution Subsidence, and volcanic deformation) with different displacement patterns in a selection of Subsidence areas in Spain. Finally, a cost comparative study is performed for the different techniques applied.
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persistent scatterer interferometry Subsidence data exploitation using spatial tools the vega media of the segura river basin case study
Journal of Hydrology, 2011Co-Authors: Roberto Tomas, Gerardo Herrera, G Cooksley, J MulasAbstract:Summary The aim of this paper is to analyze the Subsidence affecting the Vega Media of the Segura River Basin, using a Persistent Scatterers Interferometry technique (PSI) named Stable Point Network (SPN). This technique is capable of estimating mean deformation velocity maps of the Ground surface and displacement time series from Synthetic Aperture Radar (SAR) images. A dataset acquired between January 2004 and December 2008 from ERS-2 and ENVISAT sensors has been processed measuring maximum Subsidence and uplift rates of −25.6 and 7.54 mm/year respectively for the whole area. These data have been validated against Ground Subsidence measurements and compared with Subsidence triggering and conditioning factors by means of a Geographical Information System (GIS). The spatial analysis shows a good relationship between Subsidence and piezometric level evolution, pumping wells location, river distance, geology, the Arab wall, previously proposed Subsidence predictive model and soil thickness. As a consequence, the paper shows the usefulness and the potential of combining Differential SAR Interferometry (DInSAR) and spatial analysis techniques in order to improve the knowledge of this kind of phenomenon.
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mapping Ground Subsidence induced by aquifer overexploitation using advanced differential sar interferometry vega media of the segura river se spain case study
Remote Sensing of Environment, 2005Co-Authors: Roberto Tomas, Gerardo Herrera, J J Mallorqui, Juan M Lopezsanchez, Yolanda Marquez, Jose Delgado, Pablo Blanco, Monica Martinez, J MulasAbstract:Differential SAR Interferometry (DInSAR) is a remote sensing technique with the well-proven ability to monitor Ground deformations. In this work we have applied an advanced DInSAR technique – the Coherent Pixels Technique (CPT) – , to study Subsidence phenomena due to the excessive pumping of Groundwater in the Vega Media of the Segura River (SE Spain) from 1993 to the present. The settlement map retrieved with DInSAR shows settlement of up to 8 cm at some points of the study area and has been compared with other data provided by Ground instruments to analyse the relationship with Ground deformation. A correlation has been observed between these measurements and the observations from on-site testing of piezometric Groundwater fluctuations and borehole extensometric settlement. However, the distribution of damaged buildings, well points and basements does not show a clear relationship with measured Subsidence values because the occurrence of damage also depends on the structural state of the buildings and the characteristics of their foundations. In addition, the distribution of pumping wells is not indicative of the distribution of the volume of water withdrawal which is the real conditioning factor of piezometric level changes. It can be concluded that the results obtained provide very useful spatial and temporal data about this phenomenon in an urban area at a low cost. The data can be used for forecasting purposes and helps to define zones with future Ground settlement problems if the same conditions are repeated. This technique has also allowed the monitoring of Ground Subsidence in the Vega Media of Segura River for a period (1993–1995) where no instrument information was available.
