948 research outputs found

    GMES-service for assessing and monitoring subsidence hazards in coastal lowland areas around Europe. SubCoast D3.5.1

    Get PDF
    This document is version two of the user requirements for SubCoast work package 3.5, it is SubCoast deliverable 3.5.1. Work package 3.5 aims to provide a European integrated GIS product on subsidence and relative sea level rise. The first step of this process was to contact the European Environment Agency as the main user to discover their user requirements. This document presents these requirments, the outline methodology that will be used to carry out the integration and the datasets that will be used. In outline the main user requirements of the EEA are: 1. Gridded approach using an Inspire compliant grid 2. The grid would hold data on: a. Likely rate of subsidence b. RSLR c. Impact (Vulnerability) d. Certainty (confidence map) e. Contribution of ground motion to RSLR f. A measure of certainty in the data provided g. Metadata 3. Spatial Coverage - Ideally entire coastline of all 37 member states a. Spatial resolution - 1km 4. Provide a measure of the degree of contribution of ground motion to RSLR The European integration will be based around a GIS methodology. Datasets will be integrated and interpreted to provide information on data vlues above. The main value being a likelyhood of Subsidence. This product will initially be developed at it’s lowest level of detail for the London area. BGS have a wealth of data for london this will enable this less detialed product to be validated and also enable the generation of a more detailed product usig the best data availible. One the methodology has been developed it will be pushed out to other areas of the ewuropean coastline. The initial input data that have been reviewed for their suitability for the European integration are listed below. Thesea re the datasets that have European wide availibility, It is expected that more detailed datasets will be used in areas where they are avaiilble. 1. Terrafirma Data 2. One Geology 3. One Geology Europe 4. Population Density (Geoland2) 5. The Urban Atlas (Geoland2) 6. Elevation Data a. SRTM b. GDEM c. GTOPO 30 d. NextMap Europe 7. MyOceans Sea Level Data 8. Storm Surge Locations 9. European Environment Agencya. Elevation breakdown 1km b. Corine Land Cover 2000 (CLC2000) coastline c. Sediment Discharges d. Shoreline e. Maritime Boundaries f. Hydrodynamics and Sea Level Rise g. Geomorphology, Geology, Erosion Trends and Coastal Defence Works h. Corine land cover 1990 i. Five metre elevation contour line 10. FutureCoas

    Solo - Projection Mapping

    Get PDF
    Projection Artists Luke McConnell and Jordan Foster will project a multicoloured lightshow onto the clockface, roof and walls of St Peter’s Cathedral. Wintec Tutors McConnell & Foster plan to transform the Hamilton night skyscape this Christmas with their projection work entitled ‘SOLO’. Solo is a piece designed to complement the Victoria street Christmas revellers taking in the sights of the Garden Place Christmas tree and the Trees at the Meteor art exhibition. One seamless image across the surface of the building by linking three powerful 7k projectors. The animation will interact with the forms of the building with a particular focus on the clock tower - which should be visible from quite a distance. The projected animation invites the viewer to think about the connections that we make during this busy Christmas season. Hamiltonians too get caught up on the silly season and rarely get a chance to stop and think. ‘Solo’ will encourage people to think about how they can better connect with others in their community. The animation will run for about 5 minutes and will loop over the evening

    Environmental baseline monitoring for shale-gas development: insights for monitoring ground motion using InSAR analysis

    Get PDF
    Shale gas operations can be contentious, with a degree of uncertainty regarding the effects that they may, or may not, have on the environment. Several countries have moratoria on hydraulic fracturing until its potential effects can be understood better. One area of debate is whether operations could cause ground motion at the surface. This research monitored ground motion prior to operations and compared that baseline to the situation during and after shale gas operations. The test sites are the Vale of Pickering (North Yorkshire) and the Fylde (Lancashire) in the UK. Planning permission was granted in May 2016 to undertake hydraulic fracturing near Kirby Misperton (Vale of Pickering) and in August 2018 at Preston New Road in Lancashire. Hydraulic fracturing has only taken place at Lancashire as it was the only site to also get the hydraulic fracturing plan approved. Complementary Interferometric Synthetic Aperture Radar (InSAR) techniques were used to process archive and current satellite images to detect relative ground motion with millimetric accuracy in rural and semi-urban landcover. The SBAS, ISBAS and RapidSAR processing for the period from 1992 to 2019 (extending 24 years prior to hydraulic fracturing) identified broad regions with little or no surface motion, along with discrete zones of uplift or subsidence. Analysis of the average velocities and time-series data revealed that the motion, where it occurred, related to factors including compressible ground, groundwater abstraction and underground coal mining. This research concluded that the shale gas operations in Lancashire did not alter the baseline ground motion dynamics to date, as detected by InSAR. The successful application of InSAR for detecting and monitoring ground motion at shale gas sites in rural landcover in the UK, where radar coherence has traditionally been a major challenge, serves as a precedent for other regions where baseline monitoring is required

    Making Infrastructure Procurement Processes more Flexible under Uncertainty

    Get PDF
    A third to a half of development projects undergo restructuring due to changes in project objectives, scope or other unanticipated changes, therefore requiring schedule extensions, budget additions and rework. Current procurement processes discourage managers from responding strategically by anticipating and preparing for such changes in advance through better information search and design concept evaluation. This paper suggests three principles for making the front-end phases of procurement more flexible - understanding uncertainty, studying system-wide impacts, and phasing designs. A case study analysis of urban water system design in Kabul demonstrates the conceptual and analytical application of these principles

    Nationwide monitoring of geohazards in Great Britain with InSAR: feasibility mapping based on ERS-1/2 and ENVISAT imagery

    Get PDF
    We model terrain visibility and topographic distortions to the ERS-1/2 SAR and ENVISAT ASAR IS2 satellite acquisition modes in Great Britain using the 5m NEXTMap DTM. Predictions of Persistent Scatterers (PS) densities identifiable over the landmass are drawn using the CORINE Land Cover 2006 dataset which is calibrated based on 6 PS datasets available for various areas of the UK. InSAR feasibility to monitor ground motions is discussed through the example of the Manchester area, with particular regard to landslide deposits in the Peak District

    Natural and anthropogenic geohazards in Greater London observed from geological and ERS-1/2 and ENVISAT Persistent Scatterers ground motion data: results from the EC FP7-SPACE PanGeo Project

    Get PDF
    We combine geological data and ground motion estimates from satellite ERS-1/2 and ENVISAT persistent scatterer interferometry (PSI) to delineate areas of observed natural and anthropogenic geohazards in the administrative area of Greater London (United Kingdom). This analysis was performed within the framework of the EC FP7-SPACE PanGeo project, and by conforming to the interpretation and geohazard mapping methodology extensively described in the Production Manual (cf. http://www.pangeoproject.eu). We discuss the results of the generation of the PanGeo digital geohazard mapping product for Greater London, and analyse the potential of PSI, geological data and the PanGeo methodology to identify areas of observed geohazards. Based on the analysis of PSI ground motion data sets for the years 1992–2000 and 2002–2010 and geology field campaigns, we identify 25 geohazard polygons, covering a total of ~650 km2. These include not only natural processes such as compaction of deposits on the River Thames flood plain and slope instability, but also anthropogenic instability due to groundwater management and changes in the Chalk aquifer, recent engineering works such as those for the Jubilee Line Extension project and electricity tunnelling in proximity to the River Thames, and the presence of made ground. In many instances, natural and anthropogenic observed geohazards overlap, therefore indicating interaction of different processes over the same areas. In terms of ground area covered, the dominant geohazard is anthropogenic land subsidence caused by groundwater abstraction for a total of ~300 km2, followed by natural compression of River Thames sediments over ~105 km2. Observed ground motions along the satellite line-of-sight are as high as +29.5 and −25.3 mm/year, and indicate a combination of land surface processes comprising ground subsidence and uplift, as well as downslope movements. Across the areas of observed geohazards, urban land cover types from the Copernicus (formerly GMES) EEA European Urban Atlas, e.g., continuous and discontinuous urban fabric and industrial units, show the highest average velocities away from the satellite sensor, and the smallest standard deviations (~0.7–1.0 mm/year). More rural land cover types such as agricultural, semi-natural and green areas reveal the highest spatial variability (up to ~4.4 mm/year), thus suggesting greater heterogeneity of observed motion rates within these land cover types. Areas of observed motion in the PSI data for which a geological interpretation cannot be found with sufficient degree of certainty are also identified, and their possible causes discussed. Although present in Greater London, some geohazard types such as shrink–swell clays and ground dissolution are not highlighted by the interpretation of PSI annual motion rates. Reasons for absence of evidence of the latter in the PSI data are discussed, together with difficulties related to the identification of good radar scatterers in landsliding areas

    Simulating SAR geometric distortions and predicting Persistent Scatterer densities for ERS-1/2 and ENVISAT C-band SAR and InSAR applications: nationwide feasibility assessment to monitor the landmass of Great Britain with SAR imagery

    Get PDF
    We assess the feasibility of monitoring the landmass of Great Britain with satellite Synthetic Aperture Radar (SAR) imagery, by analysing ERS-1/2 SAR and ENVISAT IS2 Advanced SAR (ASAR) archive data availability, geometric distortions and land cover control on the success of (non-)interferometric analyses. Our assessment both addresses the scientific and operational question of whether a nationwide SAR-based monitoring of ground motion would succeed in Great Britain, and helps to understand controlling factors and possible solutions to overcome the limitations of undertaking SAR-based imaging of the landmass. This is the first time such a nationwide assessment is performed in preparation for acquisition and processing of SAR data in the United Kingdom, and any other country in the world. Analysis of the ERS-1/2 and ENVISAT archives reveals potential for multi-interferogram SAR Interferometry (InSAR) for the entirety of Britain using ERS-1/2 in descending mode, with 100% standard image frames showing at least 20 archive scenes available. ERS-1/2 ascending and both ENVISAT modes show potential for non-interferometric and single-pair InSAR for the vast majority of Britain, and multi-interferogram only for 13% to 38% of the available standard frames. Based on NEXTMap¼ Britain Digital Terrain Model (DTM) we simulate SAR layover, foreshortening and shadow to the ERS-1/2 and ENVISAT Lines-Of-Sight (LOS), and quantify changes of SAR distortions with variations in mode, LOS incidence angles and ground track angles, local terrain orientation, and the effect of scale due to the input DTM resolution. The simulation is extended to the ~ 230,000 km2 landmass, and shows limited control of local topography on the radar terrain visibility. According to the 50 m to 5 m DTM-based simulations, ~ 1.0–1.4% of Great Britain could potentially be affected by shadow and layover in each mode. Only ~ 0.02–0.04% overlapping between ascending and descending mode distortions is found, this indicating the negligible proportion of the landmass that cannot be monitored using either imaging mode. We calibrate the CORINE Land Cover 2006 (CLC2006) using Persistent Scatterer (PS) datasets available for London, Stoke-On-Trent, Newcastle and Bristol, to quantify land cover control on the PS distribution and characterise the CLC2006 classes in terms of the potential PS density they could provide. Despite predominance of rural land cover types, we predict potential for over 12.8 M monitoring targets for each acquisition mode using a set of image frames covering the entire landmass. We validate our assessment by processing with the Interferometric Point Target Analysis (IPTA) 55 ERS-1/2 SAR scenes depicting South Wales between 1992 and 1999. Although absolute differences between predicted and observed target density are revealed, relative densities and rankings among the various CLC2006 classes are found constant across the calibration and validation datasets. Rescaled predictions for Britain show potential for a total of 2.5 M monitoring targets across the landmass. We examine the use of the topographic and land cover feasibility maps for landslide studies in relation to the British Geological Survey's National Landslide Database and DiGMapGB mass movement layer. Building upon recent literature, we finally discuss future perspectives relating to the replication of our feasibility assessment to account for higher resolution SAR imagery, new Earth explorers (e.g., Sentinel-1) and improved processing techniques, showing potential to generate invaluable sources of information on land motions and geohazards in Great Britai

    Attitude Determination and Control System With Variable-Speed Single-Gimbal Control Moment Gyroscopes for Nanosatellites

    Get PDF
    This paper presents a novel Attitude Determination and Control System (ADCS) utilizing Variable-Speed Control Moment Gyroscopes (VSCMG) tailored explicitly for nanosatellites. The VSCMG was realized by spherical motor technology, in which a patented magnetic field design controls the inner rotor and gimbal. Because of the characteristics of the control moment gyroscope, the proposed ADCS offers improved attitude maneuverability and reduced power consumption, addressing the limitations of traditional ADCS solutions for nanosatellites. Furthermore, the adoption of spherical motor technology shrinks the VSCMG into a smaller form factor, which allows the VSCMG to be fitted into a nanosatellite. This research paper introduces the specifications of the integrated ADCS family based on VSCMG, as well as the components used in the system

    Heat-constrained modelling of calcium sulphate reduction

    Get PDF
    A two-dimensional finite difference model has been developed to describe the reduction of kilogram quantities of dehydrated phosphogypsum. The model’s scope has been limited to focus on the heat transfer and reactions that occur within a mass of material contained in a vessel inside a furnace rather than also including the effects of heat transfer to the vessel. Changes in the heat transfer properties (k, ρ, and Cp) are incorporated as the composition of the mass changes as the chemical reactions progress. The model is validated against experimental data, with samples heated to 1000°C at 3°C min−1 while purging with nitrogen gas. A sensitivity analysis of model predictions to the pre-exponential factor of the reaction rate constant of the main chemical reaction and the thermal conductivity of the powder bed indicated that, at the envisaged process conditions, the behaviour of the system depends much more on the rate of heat transfer than on the rate of the chemical reaction. The model demonstrated a significant increase in accuracy when the thermal conductivity was modelled to increase linearly with temperature compared to assuming a constant value.The Department of Trade, Industry and Competition of South Africa.https://journals.co.za/journal/saimmam2023Chemical Engineerin

    Kenbrook Bridge Project

    Get PDF
    The Kenbrook Bridge Team seeks to address Kenbrook Bible Camp’s need for maintenance and emergency access across a small stream on the property that separates their main office location from cabins on the northwestern portion of the campus. Kenbrook Bible Camp\u27s mission is to facilitate a closer connection to God, self, others, and nature for all guests. The bridge site was selected by the Kenbrook staff based on the greatest need for accessibility. An existing footbridge in this location cannot support passage of heavy equipment used for camp maintenance nor the ATV used for emergency response. The bridge team proposes a 16-foot-long by 8-foot-wide concrete culvert for the site. The culvert has been designed in compliance with AASHTO structural requirements and all elements of the structure are detailed in a complete drawings sheet set, serving as a reference for on-site construction in May. Funding for this work provided by The Collaboratory for Strategic Partnerships and Applied Research.https://mosaic.messiah.edu/engr2022/1001/thumbnail.jp
    • 

    corecore