Despite being labelled a relatively trivial computing problem available in many GIS applications, the use of visibility analysis to produce reliable and useful viewshed maps involves many factors from suitable digital terrain data to the GIS modelling used. The accurate and precise looking viewshed maps produced do not convey the many interacting variables involved. This study examines the relationship between digital terrain data quality and visibility analysis carried out using 2 commercially available, UK wide, digital terrain datasets and 2 GIS applications. An applied approach involved the use of GIS in archaeology and in particular viewshed analysis which is discussed along with issues such as digital terrain modelling and sources of uncertainty. A series of archaeological sites form the basis for viewshed computations and comparisons of results. Ordnance Survey’s LandForm Profile Digital Terrain Model (DTM) and NextMap’s UK Interferometric Synthetic Aperture Radar (IFSAR) DTM are used with ArcGIS and IDRISI to produce a variety of viewshed results. The two DTMs produce differing results which are not uniform but vary with terrain as the DTMs accuracies also vary with changes in terrain. Reassuringly, the two GIS applications produce similar results but small variations do occur with the levels of agreement reducing with the less refined DTM (LandForm). An important final objective of the study was to evaluate how well the GIS derived results match reality, a pertinent and sometimes overlooked question for GIS practitioners. For a selection of sites, actual viewsheds were mapped in
the field using a Differential Global Positioning System (DGPS). Results were
incorporated into the GIS for comparison. The GIS and field mapped viewsheds did show a good level of agreement. These differences were not consistent but varied with terrain and slope reflecting the difficulties in encoding and modelling such as variable entity as terrain.
In the early 2000s UK Local Authorities were challenged to electronically enable all the services that they provide to the public. The drivers for this were initiatives introduced by the Office of the Deputy Prime Minister and the Cabinet Office.
It has been identified that in order to meet these challenges a Local Authority must possess an integrated IT infrastructure where customer transactions are possible through a single piece of software. This software must act as a hub for all requests and system responses to pass through. A Customer Relationship Management (CRM) system can be used to fulfil this requirement.
- Many Local Authorities have adopted CRM for this purpose and the latest set of challenges introduced by UK government, transactional government, stresses the importance of integrating IT systems to improve the service for the customer. A way of improving the service is to speed up the time it takes to complete a transaction.
- It has been suggested that Geographical Information Systems can be used in the CRM workflow in order to speed up the lifecycle of a request. The object of this dissertation is to prove this.
- The GIS component for the CRM system has been developed as part of the dissertation. The emphasis during development was on the usability of the GIS component as the users of the component in the testing would be CRM operators in the East Riding of Yorkshire council customer services department. The operators would not necessarily have experience using GIS and this would need to be considered when developing the component.
- Once the component was developed and a series of scenarios for testing had been developed the component was tested within the CRM workflow. A comparison was made between requests with the GIS component and requests without it.
The results of the testing showed that the GIS component improved the speed of the request/response lifecycle when the information that customer required or the problem raised could be resolved in the front office (by the CRM operator). They also highlighted how important it is for information available in the front office to be correct as a level of confidence needs to be achieved in the data in the front office for the CRM operator to be happy the information they are giving is correct.
An important point for the future of GIS in this context is that the expectations of the quality of the delivery of GIS services are rapidly changing. With the introduction of extremely high quality GIS services, such as Google maps, freely available and usable on the Internet it is imperative that the quality of developments integrated into workflow is of this standard.
Geographical Information Systems (GIS) are used for a variety of uses, amongst which are spatial databases containing a wealth of information on various subjects. Heritage management in the Maltese Islands is a relatively sensitive subject due to the amount of heritage available and its propensity in certain areas including some zoned for development. This gives rise to a number of conflicts that are not very easily resolved. GIS may help resolve these conflicts if identified early.
At present there is no holistic database system of heritage assets located in the Maltese Islands , although a variety of different datasets on heritage exist. GIS may be the tool that is required in order to facilitate identification of assets whilst ensuring that adequate management is carried out.
Web mapping and web GIS are current buzz words in many published and digital articles. This study aims at exploring the status of these technologies and will attempt to assess the possibility of creating a database that can be used both by staff in heritage management entities as well as by the general public in order to report any finds, request protection of assets whilst also having substantial information easily available.
The study ends by concluding whether the technology for creation of such a system is available while attempting to assess the feasibility of such a project. An example of how such a database might contain is also proposed.
Background
This paper uses the Canadian province of British Columbia to explore the question of accessibility to emergency services in urban and rural regions. Both Euclidian and driven distance measurements are made between ambulance station locations, accident sites and hospital locations to show this discrepancy in respect distance needed to access services.
Results
Through the creation of a number of different maps, trends in the data began to occur. By using the population statistics along with the Local Health Area (LHA) regions, it was possible to create a layout that showed the differences in population counts between the different LHAs. When the adding the city center information to the map, the association was further made between the urban areas and rural areas.
Conclusions
The two separate distance measurements indicate that there are indeed differences between the two types of populated areas in respect to emergency services. The purpose of the research is to primarily answer the following question: Are British Columbians in rural areas of the province able to obtain equal access to emergency healthcare services as British Columbians in urban areas? As the study shows, there rural areas of the B.C. are left with greater distances to drive than the urban areas. Therefore, the conclusion is that access to emergency healthcare services is not consistent, and is in fact unfavourable to remote regions of the province.
Since 1994 Historic Landscape Characterisation (HLC) has been promoted as a rapid and reliable method of understanding of the development and quality of the historic landscape of England . The use of GIS is repeatedly mentioned in the HLC literature as an important component of the HLC method. This study assesses how GIS was used in English Heritage’s Historic Landscape Characterisation programme in the ten years between its inception and 2004. This assessment was by means of a review of the archaeological literature on GIS and HLC, and the collection of the views of environment professionals on a selected HLC project by means of a questionnaire.
Significant weaknesses were found in the HLC method, particularly with regard to its selection and implementation of a GIS data model and its failure to consider that implementation in conjunction with relevant archaeological theory. The study concludes that a major modification of the HLC method to make use of raster GIS was necessary, along with greater GIS training for archaeologists participating in HLC projects.
Hyperspectral sensors, or imaging spectrometers, simultaneously collect tens or hundreds of identical images in narrow, contiguous wavelength intervals. Each pixel is then a quantization of the continuous spectrum at a given spatial location. Absorption and scattering by molecules and aerosols in the atmosphere attenuate solar radiation and consequently modify the signal received by the sensor. Quantitative analysis of the composition and abundance of minerals in rocks and soils generally requires the removal of atmospheric effects from hyperspectral image data.
Atmospheric correction, also known as inversion or calibration, attempts to remove the effects of the atmosphere from the image data. Many techniques exist that range in requirements of knowledge about surface composition and atmospheric properties in the imaged area.
Generally, the most effective methods make use of field spectral and atmospheric measurements collected at or near the time of sensor overpass.
Analysts wishing to make use of archived hyperspectral imagery will likely have no spectral or atmospheric data collected at the time of sensor overpass. This thesis develops strategies for effectively using these images in the absence of ground-truth data collected at the time of sensor overpass. It examines how different atmospheric inversion techniques affect the accuracy of spectral mapping algorithms and our ability to correctly identify minerals on the ground.
A quantitative comparison of mapping algorithm performance was conducted. Map accuracy and the ability to identify materials through spectral comparisons were quantitatively assessed using a factorial designed experiment. It has been shown that, in some cases, field measurements collected at a time other than sensor overpass may be effectively used to correct for the atmosphere. Finally, taxonomy of strategies for the selection of atmospheric correction method and mapping algorithm combination is presented.
The idea of sharing geographic data both within and between organisation remains largely resisted despite the obvious benefits that can be derived from data sharing activities and the initiatives that promote them.
This research examines the various properties of data sharing activities, as well as measure the organisational culture that impact on geospatial data exchange across organisational boundaries in Sharjah GI community.
The findings suggest that organisational members have a number of different reasons for entering into cooperative relationship. With greater number of private sector forming the bulk of GIS community in Sharjah, cost-sharing and partnership is the bed-rock of any data sharing projects when it comes to financing of projects.
It was found that data exchange activities among organisations is guided by formalized mechanism. Informal interactions, however, continue to be significant in facilitating those interactions among governments departments.
haring policy to guide data exchange arrangements is not in place in Sharjah, and the absence is weighing heavily on geospatial data sharing.
Spatial analysis of crime data by Local Authority Officers via the Tyne & Wear ‘AreaProfiler’ is dependant on data with a high level of accurate geocoding. This enables point-level data to be aggregated to higher geographies with fewer spatial errors.
In order to provide evidence of the success and efficiency of the geocoding procedures undertaken by Tyne & Wear Research and Information, the principal aim of this research is to evaluate “how much does TWRI improve the spatial accuracy of crime data.” This is assessed in terms of the improvement in the geocoding hit rate (the percentage measure of success) for a sample of crime data, as well as providing information on the distribution of the positional errors and a maximum expected error of this sample. Reasons behind the large distribution of positional errors are provided.
This paper also discusses the importance of Data Quality Management Techniques, in particular the use of Data Quality Reports and metadata, in providing information on the quality, defined as the fitness-for-purpose, of the sample data. The use of Data Quality Reports and metadata is recommended within the paper, to provide a qualitative description of the dataset which can be used by potential data users, to make informed decisions regarding the appropriateness and reliability of the data, as well as noting any restrictions on its use.
This project looks at the process of data generation within the Maltese Islands that have been instigated through the European Union accession process and those that are currently being envisaged in order to develop an integrated environmental spatial information system. The aim was to bring together a number of disparate datasets within one centralised interactive system.
The study’s aim was to research the viability of environmental information datasets in terms of need, creation methodology and eventual use. It aimed to understand the scientific process taken to develop such a system in an organisation that did not employ spatial methodologies in its process i.e. the Environment Protection Department. This study is based on an analysis of a number of legal notices, transposition and legal processes. It looks at the legal requirements, local laws and datasets originating from these requirements as well as the actual datasets created. It looks at the interactivity between the datasets, the issues brought up in creating them and the data creation, analysis and distribution process.
Lastly it analyses the problems encountered, how the issues were tackled and recommendations proposed for the improvement of the product.
I
‘as the island of our knowledge expands, the shore of our ignorance also stretches’(Sui, 2004, p.65) Information and communications technology (ICT) has become fundamental to the operations of organisations and communities worldwide, with huge sums of money, resources and user expectations invested in their implementation. Yet many ICT projects fail
to achieve their objectives. There is widespread agreement that one of the most significant factors in the successful implementation of ICT in an organisation is its staff, their knowledge, skills, experience, motivation and commitment. Thus, an understanding of how individuals and organisations learn to use and adapt to ICT is crucial in order to promote the success of ICT projects and secure the best value from the investment.
This dissertation focuses on the implementation of a particular type of ICT, namely Geographical Information Systems (GIS), in a particular type of organisation, namely local government, whose operations are especially relevant to society as they touch on almost every aspect of everyday life. In line with the expansion in ICT services generally, GIS usage in local authorities is expanding rapidly: the technology is considered fundamental to the achievement of local e-government, facilitating ‘joined-up’ services and access to information. GIS are complex, offering numerous opportunities for future development as well as considerable scope for things to go wrong, and thus present a particularly acute learning issue.
Against this background, this dissertation explores ways in which the development of GIS knowledge and skills in the local government sector can be supported by investigating the challenges facing local authority officers at all levels of experience in 'learning' GIS, and local authorities in helping their staff to make effective use of new GIS technologies. In doing so,the dissertation first investigates the context of individual and organisational learning and training, the nature of geographical skills and knowledge, and recent initiatives in GIS training. It then reviews training opportunities and providers available to local government in order assess the types of user and skill levels likely to be addressed by these. It uses an edelivered questionnaire survey to gauge the types of GIS training currently offered to local government staff by their employers, their preferred training routes and future requirements. In order to gain a deeper understanding of the processes at play in GIS training and skills development in local authorities, this was supplemented by an in-depth case study of a local authority moving towards a competency-based approach to training and staff development, and three smaller comparative studies.
The findings of this multi-stage research process lead to the proposal of a framework for enhancing GIS skills within local authorities in the UK . This outlines a series of ‘pathways’ of learning options which may be followed by staff with varying levels of GIS knowledge, skills and requirements in order to build the understanding necessary to make good use of GIS technologies now and into the future. In this way, it is hoped that those factors which ‘often prove the hardest to get right’ (Tansey, 2003) may be effectively addressed.
Ancient woodland is a diminishing resource in Great Britain with most areas small and fragmented. If these woodlands are to survive not only must they be protected by legislation but also the trees must be allowed to regenerate whether naturally or by a planned planting regime. This study looked briefly at four Special Areas of Conservation (Sacs) with oak, Quercus robur, on sandy soils. It became apparent that the authorities responsible for these woodlands often do not have detailed data available and even if they do it is frequently in a form that is difficult to interrogate or see spatially. With this paucity of data and limited GIS systems it was difficult or impossible to pinpoint areas suitable for oak regeneration within the SACs.
This study sort to develop a methodology to accurately record data, query that data and statistically analyse it to indicate areas for potential oak regeneration. By using a GIS system, in this case, MapInfo and a MapBasic program it was possible to interrogate the data and display the results visually. In conjunction with a statistical analysis using SPSS 12.1 it became possible to see significant relationships between the recorded variables. This enabled potential sites for oak regeneration to be highlighted within the study area.
The study showed that by using GIS and statistical methods in the study of ancient woodland it was possible for woodland managers to have a more scientific basis for regeneration site selection. This possibly may help to avoid expensive errors in planting saplings in unsustainable areas in woodland where natural regeneration is limited or absent.
Non-Combatant Evacuation Operations (NEOs) are undertaken by the UK MOD in order to safely relocate threatened entitled persons in a foreign country to a place of safety. Various contingency plans are maintained of high risk areas to help achieve this. These are, however, created and maintained independently of each other and none in a softcopy format. It was proposed that a Geographical Information System may provide the solution to amalgamate the information and display the data through a geographical interface. Additionally, by bringing the data into an intelligent, spatially aware format, the possibility of using GIS functions to assist operationally could be highlighted.
A requirements analysis was undertaken which researched past Non-Combatant Evacuation Operations and investigated current initiatives in using GIS to assist in their management. A literature review was undertaken and doctrine from several allied countries studied in order to extract the geographical aspects. Past NEO reports were analysed, non-government approaches to GIS & relief reviewed and interviews or meetings were held with the key players involved in planning or implementing NEOs.
The research provided a detailed list of geographical requirements which could be incorporated into a GIS project. By integrating the data from various sources, a more detailed picture of the operational environment could be established, allowing contingency planners and operational commanders to make more informed decisions.
The practical research indicates that there is a pressing need for a spatially aware product to assist in UK NEO planning and management. The research also highlighted the drawbacks in working independently of other nations. NEOs are multinational by their very nature and any product developed should take into account joint doctrine, collaborative working, interoperability issues and international standards.
Time is inherent in geographic information. Geographic entities exist and change in time as well as space. Yet when these entities are modelled within conventional Geographic Information Systems (GIS) time is frozen.
If GIS are to truly model geographic phenomena time as well as space will need to be represented. A temporal GIS (TGIS) is an attempt represent spatial objects and changes in their geometry, topology and attributes through time. Within a TGIS geographic entities may be queried about “when” as well as “what” and “where”.
The development of TGIS is considered to have its beginnings with Langran’s work in the late 1980s and her publication in 1992 of “Time in Geographic Information Systems” (Langran, 1992). Despite the amount of spatio-temporal research reported in the literature since then a disparity exists between these models and prototypes and the implementation of TGIS by GIS vendors within commercial GIS software.
This thesis demonstrates that while TGIS is a complex topic involving conceptual and technical challenges the research has proposed solutions which are viable within the current framework of commercial GIS, but which have not emerged as commercial solutions, the reasons for which have been discussed. This thesis develops a simple conceptual model suitable for tracking discrete changes of the types encountered by the National Parks & Wildlife Service (NPWS).
To summarise, t he objective of this thesis was to investigate the significant body of TGIS research, particularly with respect to spatio-temporal prototypes and data models, and compare this with the implementation of support for temporal data within commercial software. The research examined spatio-temporal models which may be implemented within existing commercial software using examples based on NPWS requirements. The thesis concludes by considering the discrepancy between research and commercial implementation and by evaluating some future directions for TGIS.
South-eastern Australia is one of the most fire prone regions in the world. Since 1960 wildfires have burnt 4.8 million hectares of land and claimed 123 lives in the state of Victoria . The suppression of wildfires requires knowledge of fire behaviour, which determines the rate and direction that the fire spreads. There are three factors that determine fire behaviour; weather, topography and fuel. Fire managers have good information on weather patterns and forecasts, and excellent mapping products depicting the topography. However, there is little information on the fuel hazard within areas they manage. Often the time since an area was last burnt is used to guess what the fuel hazard level might be.
This project reports on the process to develop fuel hazard models for three vegetation types: Lowland Forest ; Heathy Dry Forest ; and, Shrubby Dry Forest . Fuel hazard assessments were conducted in over 200 sites in central Gippsland , Victoria . Fuel hazard formulas were then developed for each vegetation type using the STATISTICA statistics package, and the results displayed as graphs. The fuel hazard formulas were then modelled in Excel to illustrate the increase in fuel hazard from the period immediately post fire to 25 years post fire, for each vegetation type. The fuel hazard models were then linked in ArcView 3.3 to a derived GIS dataset created from intersecting the vegetation type and the fire history datasets for the study area.
The resulting forest fuel hazard dataset was spatially modelled according to predefined hazard classifications, and the modelled data verified through additional fieldwork. The verification process demonstrated that the models were reliable in estimating the fuel hazard levels. The field values either matched the modelled values or were generally within the 95% confidence range for the data. Where the confidence levels had not been calculated, the field values were shown to be similar to the initial fuel hazard assessments for that fire year.
Once the fuel hazard models have been developed, the spatial fuel hazard layer can be recreated annually after the fire history dataset has been updated. This method provides an easily repeatable process of maintaining a current fuel hazard layer. Fire management officers will now have access to data layers depicting fuel hazards, which will aid fire suppression activities and the planning of prescribed burns.
The confluence of previously divergent technologies like Telecommunication, Positioning, Internet and Spatial databases has extended the possibilities of making GIS an enabling technology. RFID, Wi-Fi, WiMax are emerging technologies that have redefined the methodology for providing location based services. Mobile GIS solution requires multi tier client/server architecture for effective implementation and this architecture shall be investigated. Scripting standards like XML, GML, Java and software’s like Scalable Vector Graphics (SVG) have made it possible to provide solutions that provide true interoperability across wide types of data formats; the study shall investigate and analyze how interoperability is supported by using Mobile GIS solutions.
This dissertation provides an overview of the factors affecting the choice and design of a Mobile GIS solution and further suitable recommendations are made for future implementations. Technical skills and regional issues like language, ethics will be addressed and their effect on development of Mobile GIS in the Middle East region and UAE in particular will be addressed by undertaking a Case Study of a recently implemented Mobile GIS project at Sharjah Municipality.
The Charleston Earthquake of 1886 was a devastating event that caused many casualties plus considerable property loss. The earthquake was the largest ever recorded in the eastern United States at between 7.1 and 7.6 on the Richter scale. Several eyewitnesses observed precursor activity before the earthquake struck. These phenomena included release of subsurface gases, strange behavior of animals, and ground deformation. There is strong evidence that precursors are associated with the tremendous forces of deformation. Stress put on rocks and minerals will cause electromagnetic radiation to be released. In some cases groundwater and gases are released as interstitial compartments are deformed. In other cases ground movement is observable as rock formations are being deformed prior to an earthquake. Developments in satellite technology in the later part of the 20 th century and early 21 st century shows promise as a tool for earthquake forecasting. In several cases, infrared radiation and extremely low frequency (ELF) magnetic signals have been picked up by satellite prior to an earthquake event. Synthetic Aperture Radar (SAR) is currently being studied as a tool to detect ground deformation that will give warning to an impending earthquake.
The principle aim of this study was to show how remote sensing data may be used to identify earthquake precursors in the Charleston Seismic Region. Eyewitness accounts of unusual phenomena prior to the 1886 earthquake were researched. An earthquake model was presented based on the best available geologic and geophysical information from the region. A comparison was also made with other seismic regions where precursors have been detected, prior to an earthquake. Imagery was acquired, processed and analyzed in an attempt to identify a precursor associated with a modern seismic event in the Charleston Area. Finally, an earthquake forecasting system for the Charleston Seismic Region that combines GIS and Imaging software was described.
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