scholarly journals Incorporating Persistent Scatterer Interferometry and Radon Anomaly to Understand the Anar Fault Mechanism and Observing New Evidence of Intensified Activity

2021 ◽  
Vol 13 (11) ◽  
pp. 2072
Author(s):  
Ali Mehrabi ◽  
Saied Pirasteh ◽  
Ahmad Rashidi ◽  
Mohsen Pourkhosravani ◽  
Reza Derakhshani ◽  
...  
Keyword(s):  
Radon Concentration ◽  
Normal Component ◽  
Fault Analysis ◽  
Displacement Rate ◽  
Supporting Evidence ◽  
High Concentration ◽  
Large Area ◽  
Persistent Scatterer Interferometry ◽  
Persistent Scatterer ◽  
New Evidence

Interferometric Synthetic Aperture Radar (InSAR) monitors surface change and displacement over a large area with millimeter-level precision and meter-level resolution. Anar fault, with a length of ~200 km, is located in central Iran. Recent seismological studies on the fault indicated that it is approaching the end of its seismic cycle. Although a large earthquake is imminent, the mechanism of the fault is not well understood. Therefore, understanding and discovering the mechanism of Anar fault remains a challenge. Here, we present an approach of displacement fault analysis utilizing a combination of InSAR data obtained from the persistent scatterer interferometry (PSI) method and 178 Sentinel-1 images (ascending and descending) (2017–2020). We incorporated groundwater samples from 40 wells, radon concentration anomaly mapping, Global Positioning System (GPS), and 3D displacement measurement acquired over four years (2016–2020). We investigated and monitored the deformation of the fault plate’s behavior over the last three years (2017–2020) to explore new evidence and signature of displacement. The results show that the time series analysis in the fault range has an increasing displacement rate in all dimensions. We observed that the line-of-sight (LOS) displacement rate varied from −15 mm to 5 mm per year. Our calculations show that the E–W, N–S, and vertical displacement rates of the fault blocks are 2 mm to −2 mm, 6 mm to −6 mm, and 2 mm to −4 mm per year, respectively. An anomaly map of the radon concentration shows that the complete alignment of the high concentration ranges with the fault strike and the radon concentration increased on average from 23.85 Bq/L to 25.30 Bq/L over these three years. Therefore, we predict rising the radon concentration is due to the increase in activity which resulted in a deformation. Finally, our findings show that the Anar fault is an oblique and right-lateral strike-slip with a normal component mechanism. We validated the proposed method and our results by comparing the GPS field data and PSI measurements. The root mean square error (RMSE) of the PSI measurement is estimated to be 0.142 mm. Based on the supporting evidence and signature, we conclude that the Anar fault activity increased between 2017 and 2020.

scholarly journals GROUND-BASED & SPACEBORNE SAR INTERFEROMETRIC TECHNIQUES SUPPORTING THE MANAGEMENT OF EMERGENCIES IN THE HEIMDALL PROJECT

2020 ◽  
Vol XLIII-B3-2020 ◽  
pp. 1685-1690
Author(s):  
J. A. Navarro ◽  
G. Luzi ◽  
O. Monserrat ◽  
M. Crosetto
Keyword(s):  
Data Exchange ◽  
Large Area ◽  
Persistent Scatterer Interferometry ◽  
Sar Images ◽  
Scenario Building ◽  
Response Planning ◽  
Persistent Scatterer ◽  
Response And Recovery ◽  
Software And Hardware

Abstract. This paper describes the application of spaceborne and Ground Based radar interferometry as a tool for assisting the management of emergencies related to land movements. The support of the two techniques is carried out integrating some products, using tools available from a software and hardware architecture specifically developed within HEIMDALL, a H2020 project, devoted to providing a multi-hazard Cooperative Management, for Data Exchange, Response Planning and Scenario Building. Deformation maps obtained processing Sentinel-1 SAR images, updated every six days, can provide information over a large area, to be used during the preparedness and recovery phases. Data acquired through a Ground Based SAR system installed in-situ, provide a continuous and discontinuous (periodical) monitoring, aiming at supporting response and recovery phases. The products, in both cases, consist of deformation maps and temporal series, velocity of displacement, obtained through the application of Persistent Scatterer Interferometry (PSI).

WikiRecs primary care: developing rapid recommendations for primary care through effective collaboration between systematic review and guideline teams

2018 ◽  
Vol 68 (suppl 1) ◽  
pp. bjgp18X697085
Author(s):  
Trudy Bekkering ◽  
Bert Aertgeerts ◽  
Ton Kuijpers ◽  
Mieke Vermandere ◽  
Jako Burgers ◽  
...  
Keyword(s):  
Systematic Review ◽  
Primary Care ◽  
Clinical Practice ◽  
Primary Care Physicians ◽  
Urinary Stones ◽  
Care Practice ◽  
Supporting Evidence ◽  
Supervised Exercise ◽  
Review Team ◽  
New Evidence

BackgroundThe WikiRecs evidence summaries and recommendations for clinical practice are developed using trustworthy methods. The process is triggered by studies that may potentially change practice, aiming at implementing new evidence into practice fast.AimTo share our first experiences developing WikiRecs for primary care and to reflect on the possibilities and pitfalls of this method.MethodIn March 2017, we started developing WikiRecs for primary health care to speed up the process of making potentially practice-changing evidence in clinical practice. Based on a well-structured question a systematic review team summarises the evidence using the GRADE approach. Subsequently, an international panel of primary care physicians, methodological experts and patients formulates recommendations for clinical practice. The patient representatives are involved as full guideline panel members. The final recommendations and supporting evidence are disseminated using various platforms, including MAGICapp and scientific journals.ResultsWe are developing WikiRecs on two topics: alpha-blockers for urinary stones and supervised exercise therapy for intermittent claudication. We did not face major problems but will reflect on issues we had to solve so far. We anticipate having the first WikiRecs for primary care available at the end of 2017.ConclusionThe WikiRecs process is a promising method — that is still evolving — to rapidly synthesise and bring new evidence into primary care practice, while adhering to high quality standards.

Morphologic and Engineering Characteristics of East Wasit Watersheds Feeding the Al-Shewicha Trough in Iraq

2020 ◽  
Vol 55 (1) ◽  
Author(s):  
Mohammed S. Shamkhi ◽  
Jasim Mohammed Ridha Azee ◽  
Ali A. Abdul-Sahib
Keyword(s):  
Peak Flow ◽  
Flood Hazard ◽  
Bare Soil ◽  
Elongation Ratio ◽  
High Concentration ◽  
Large Area ◽  
Coarse Texture ◽  
Loam Soil ◽  
High Runoff ◽  
Group B

The Al-Shewicha Trough represents a serious flood hazard to Kut City (the capital of Wasit Province, Iraq) and to the other cities along the Tigris River downstream Kut Barrage, especially in heavy monsoon years. In this study, The Geographic Information System software ArcGIS was used in the morphologic analysis of six river basins that represent the main feeding sources for the Al-Shewicha Trough. The results revealed that the high values for the greatest length of Basins 1, 5, and 6 meant that these watersheds had high concentration time (tc) values, which delay peak flow. All basins consisted of very coarse and permeable subsurface strata that were of coarse texture. Circularity ratio form factor and elongation ratio suggested an elongated shape for all basins with lower peak flow and long duration. Analyses of soil data demonstrated that the soil type that covered a large area was loam soil (classified as hydrologic soil group B), which indicates that all basins had low permeability and high runoff. The predominant land use was bare soil, and all basins had a covering of poor vegetation, which highlighted the fact that basins were highly susceptible to erosion, thus resulting in the generation of higher sedimentation.

scholarly journals Semi-Automatic Identification and Pre-Screening of Geological–Geotechnical Deformational Processes Using Persistent Scatterer Interferometry Datasets

2019 ◽  
Vol 11 (14) ◽  
pp. 1675 ◽  
Author(s):  
Tomás ◽  
Pagán ◽  
Navarro ◽  
Cano ◽  
Pastor ◽  
...  
Keyword(s):  
Regional Scale ◽  
Central Italy ◽  
Geographical Information ◽  
External Information ◽  
Automatic Identification ◽  
Persistent Scatterer Interferometry ◽  
Active Deformation ◽  
Persistent Scatterers ◽  
Persistent Scatterer ◽  
Map Scale

This work describes a new procedure aimed to semi-automatically identify clusters of active persistent scatterers and preliminarily associate them with different potential types of deformational processes over wide areas. This procedure consists of three main modules: (i) ADAfinder, aimed at the detection of Active Deformation Areas (ADA) using Persistent Scatterer Interferometry (PSI) data; (ii) LOS2HV, focused on the decomposition of Line Of Sight (LOS) displacements from ascending and descending PSI datasets into vertical and east-west components; iii) ADAclassifier, that semi-automatically categorizes each ADA into potential deformational processes using the outputs derived from (i) and (ii), as well as ancillary external information. The proposed procedure enables infrastructures management authorities to identify, classify, monitor and categorize the most critical deformations measured by PSI techniques in order to provide the capacity for implementing prevention and mitigation actions over wide areas against geological threats. Zeri, Campiglia Marittima–Suvereto and Abbadia San Salvatore (Tuscany, central Italy) are used as case studies for illustrating the developed methodology. Three PSI datasets derived from the Sentinel-1 constellation have been used, jointly with the geological map of Italy (scale 1:50,000), the updated Italian landslide and land subsidence maps (scale 1:25,000), a 25 m grid Digital Elevation Model, and a cadastral vector map (scale 1:5,000). The application to these cases of the proposed workflow demonstrates its capability to quickly process wide areas in very short times and a high compatibility with Geographical Information System (GIS) environments for data visualization and representation. The derived products are of key interest for infrastructures and land management as well as decision-making at a regional scale.

scholarly journals Persistent Scatterer Interferometry of Sentinel-1 time series to detect ground subsidence in the city of Recife, Brazil

2020 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Enton Bedini
Keyword(s):  
Time Series ◽  
Ground Subsidence ◽  
Persistent Scatterer Interferometry ◽  
Persistent Scatterer ◽  
Radar Imagery ◽  
Long Time ◽  
Satellite Radar ◽  
Surrounding Areas ◽  
Satellite Radar Imagery ◽  
The City

Persistent Scatterer Interferometry (PSI) analysis of Sentinel-1 time series was carried out to detect ground subsidence in the city of Recife, Brazil. The dataset consisted of sixty-eight Sentinel-1A Interferometric Wide (IW) Single Look Complex (SLC) images of the time period April 2017 – September 2019. The images were acquired in descending orbit in VV (vertical transmitting, vertical receiving) polarization. The results of the PSI analysis show that in the city of Recife occur several ground subsidence areas. The largest ground subsidence area occurs between the neighborhoods of Afogados, Torrŏes and Cordeiro. The subsidence rates in this area range from few mm/year up to -15 mm/year. This ground subsidence could be a result of groundwater extraction or of subsidence processes in urbanized reclaimed lands. Similar but smaller ground subsidence areas occur in several localities in Recife. In some cases, subsidence with rates of up to -25 mm/year is noted in small zones where new buildings have been constructed in the last decade. This should be due to ground settlement processes, taking a long time due to the particular soils and geology of the locality. This study can serve as a first contribution for further research on the ground subsidence hazard in the city of Recife and the surrounding areas by means of satellite radar imagery.

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