413 research outputs found

    Geographically Referenced Data for Social Science

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    An estimated 80% of all information has a spatial reference. Information about households as well as environmental data can be linked to precise locations in the real world. This offers benefits for combining different datasets via the spatial location and, furthermore, spatial indicators such as distance and accessibility can be included in analyses and models. HSpatial patterns of real-world social phenomena can be identified and described and possible interrelationships between datasets can be studied. Michael F. GOODCHILD, a Professor of Geography at the University of California, Santa Barbara and principal investigator at the Center for Spatially Integrated Social Science (CSISS), summarizes the growing significance of space, spatiality, location, and place in social science research as follows: "(...) for many social scientists, location is just another attribute in a table and not a very important one at that. After all, the processes that lead to social deprivation, crime, or family dysfunction are more or less the same everywhere, and, in the minds of social scientists, many other variables, such as education, unemployment, or age, are far more interesting as explanatory factors of social phenomena than geographic location. Geographers have been almost alone among social scientists in their concern for space; to economists, sociologists, political scientists, demographers, and anthropologists, space has been a minor issue and one that these disciplines have often been happy to leave to geographers. But that situation is changing, and many social scientists have begun to talk about a "spatial turn," a new interest in location, and a new "spatial social science" that crosses the traditional boundaries between disciplines. Interest is rising in GIS (Geographic Information Systems) and in what GIS makes possible: mapping, spatial analysis, and spatial modelling. At the same time, new tools are becoming available that give GIS users access to some of the big ideas of social science."

    Geographically referenced data for social science

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    "Die Autoren beschreiben in ihrem Beitrag den Mehrwert der Nutzung von Geodaten in den Sozialwissenschaften. Sie liefern vor allem eine Reihe praktischer Hinweise auf die Bezugsquellen von Geodaten. Beispielhaft legen sie dar, wie sich Geodaten mit Daten des Sozio-oekonomischen Panels (SOEP) kombinieren lassen. Der erste Teil ihres Beitrags enthält eine nähere Beschreibung von Geodaten und des Geographischen Informationssystems (GIS). Das zweite Kapitel beschäftigt sich mit den Zielgruppen und Nutzern, es erläutert die der Dokumentation zugrunde liegende Definition der Geodaten und zeigt die Vorzüge und Herausforderungen beim Einsatz von Geodaten in der sozialwissenschaftlichen Forschung auf. Das dritte Kapitel verdeutlicht anhand zahlreicher Beispiele das Potenzial von Geodaten als eine zusätzliche Informationsquelle für die empirische Forschung. Abschließend wird ein Überblick über verfügbare Geodaten in Deutschland und die am meisten nachgefragten Daten in den Sozialwissenschaften gegeben. Der Anhang des Beitrags enthält Internet-Links für Datenquellen, Hinweise zur verfügbaren GIS-Software und weitere Informationen." (ICI

    Methods to Improve and Evaluate Spatial Data Infrastructures

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    This thesis mainly focuses on methods for improving and evaluating Spatial Data Infrastructures (SDIs). The aim has been threefold: to develop a framework for the management and evaluation of an SDI, to improve the accessibility of spatial data in an SDI, and to improve the cartography in view services in an SDI. Spatial Data Infrastructure has been identified as an umbrella covering spatial data handling procedures. The long-term implementation of SDI increases the need for short/middle term feedbacks from different perspectives. Thus, a precise strategic plan and accurate objectives have to be defined for the implementation of an efficient environment for spatial data collection and exchange in a region. In this thesis, a comprehensive study was conducted to review the current methods in the business management literature to approach to an integrated framework for the implementation and evaluation of SDIs. In this context, four techniques were described and the usability of each technique in several aspects of SDI implementation was discussed. SDI evaluation has been considered as one of the main challenges in recent years. Lack of a general goal oriented framework to assess an SDI from different perspectives was one of the main concerns of this thesis. Among a number of the current methods in this research area, we focused on the Balanced Scorecard (BSC) as a general evaluation framework covering all perspectives in an SDI. The assessment study opened a window to a number of important issues that ranged from the technical to the cartographic aspects of spatial data exchange in an SDI. To access the required datasets in an SDI, clearinghouse networks have been developed as a gateway to the data repositories. However, traditional clearinghouse networks do not satisfy the end user requirements. By adding a number of functionalities, we proposed a methodology to increase the percentage of accessing required data. These methods were based on predefined rules and additional procedures within web processing services and service composition subjects to develop an expert system based clearinghouses. From the cartography viewpoint, current methods for spatial data presentation do not satisfy the user requirements in an SDI environment. The main presentation problem occurs when spatial data are integrated from different sources. For appropriate cartography, we propose a number of methods, such as the polygon overlay method, which is an icon placement approach, to emphasize the more important layers and the color saturation method to decrease the color saturation of the unimportant layers and emphasize the foreground layer according to the visual hierarchy concept. Another cartographic challenge is the geometrical and topological conflicts in data shown in view services. The geometrical inconsistency is due to the artificial discrepancy that occurs when displaying connected information from different sources, which is caused by inaccuracies and different levels of details in the datasets. The semantic conflict is related to the definition of the related features, i.e., to the information models of the datasets. To overcome these conflicts and to fix the topological and geometric conflicts we use a semantic based expert system by utilizing an automatic cartography core containing a semantic rule based component. We proposed a system architecture that has an OWL (Web Ontology Language) based expert system to improve the cartography by adjusting and resolving topological and geometrical conflicts in geoportals

    Notional pipeline route analysis

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    Augmented reality over maps

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    Dissertação de mestrado integrado em Engenharia InformáticaMaps and Geographic Information System (GIS) play a major role in modern society, particularly on tourism, navigation and personal guidance. However, providing geographical information of interest related to individual queries remains a strenuous task. The main constraints are (1) the several information scales available, (2) the large amount of information available on each scale, and (3) difficulty in directly infer a meaningful geographical context from text, pictures, or diagrams that are used by most user-aiding systems. To that extent, and to overcome the aforementioned difficulties, we develop a solution which allows the overlap of visual information over the maps being queried — a method commonly referred to as Augmented Reality (AR). With that in mind, the object of this dissertation is the research and implementation of a method for the delivery of visual cartographic information over physical (analogue) and digital two-dimensional (2D) maps utilizing AR. We review existing state-of-art solutions and outline their limitations across different use cases. Afterwards, we provide a generic modular solution for a multitude of real-life applications, to name a few: museums, fairs, expositions, and public street maps. During the development phase, we take into consideration the trade-off between speed and accuracy in order to develop an accurate and real-time solution. Finally, we demonstrate the feasibility of our methods with an application on a real use case based on a map of the city of Oporto, in Portugal.Mapas e Sistema de Informação Geográfica (GIS) desempenham um papel importante na sociedade, particularmente no turismo, navegação e orientação pessoal. No entanto, fornecer informações geográficas de interesse a consultas dos utilizadores é uma tarefa árdua. Os principais dificuldades são (1) as várias escalas de informações disponíveis, (2) a grande quantidade de informação disponível em cada escala e (3) dificuldade em inferir diretamente um contexto geográfico significativo a partir dos textos, figuras ou diagramas usados. Assim, e para superar as dificuldades mencionadas, desenvolvemos uma solução que permite a sobreposição de informações visuais sobre os mapas que estão a ser consultados - um método geralmente conhecido como Realidade Aumentada (AR). Neste sentido, o objetivo desta dissertação é a pesquisa e implementação de um método para a visualização de informações cartográficas sobre mapas 2D físicos (analógicos) e digitais utilizando AR. Em primeiro lugar, analisamos o estado da arte juntamente com as soluções existentes e também as suas limitações nas diversas utilizações possíveis. Posteriormente, fornecemos uma solução modular genérica para uma várias aplicações reais tais como: museus, feiras, exposições e mapas públicos de ruas. Durante a fase de desenvolvimento, tivemos em consideração o compromisso entre velocidade e precisão, a fim de desenvolver uma solução precisa que funciona em tempo real. Por fim, demonstramos a viabilidade de nossos métodos com uma aplicação num caso de uso real baseado num mapa da cidade do Porto (Portugal)

    Monitoring land use changes using geo-information : possibilities, methods and adapted techniques

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    Monitoring land use with geographical databases is widely used in decision-making. This report presents the possibilities, methods and adapted techniques using geo-information in monitoring land use changes. The municipality of Soest was chosen as study area and three national land use databases, viz. Top10Vector, CBS land use statistics and LGN, were used. The restrictions of geo-information for monitoring land use changes are indicated. New methods and adapted techniques improve the monitoring result considerably. Providers of geo-information, however, should coordinate on update frequencies, semantic content and spatial resolution to allow better possibilities of monitoring land use by combining data sets

    Regional geomorphic analysis and GIS susceptibility mapping of landslides in the Blue Nile and the Tekeze River Basins of Ethiopia

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    The Plateau region of Ethiopia lies within a seismically active continental extensional regime, which is being rapidly incised by the Blue Nile and the Tekeze Rivers. Extremely large landslides pose serious hazards in this highly populated region (\u3e27 million), which is in the process of developing its hydrologic resources. This research sought to develop cost-effective methods to compile regional landslide inventory and landslide susceptibility maps, using geomorphic tools and GIS technologies. This work also sought to evaluate the relationships between landslide dams and knickpoints, caused by channel bed incision from those caused by slope failures, by utilizing identified knickpoints along 56 tributary channels across the study area. The study employed the weighted overlay technique to produce regional landslide susceptibility hazard maps, and for the first time, employing wind-driven and integrated rainfall/aspect rasters at various inclination to more realistically model the actual precipitation that is felt by hillsides of varying azimuth, shape, and height. Landslides greater than 500m long were tentatively identified on 1:200,000 topographic maps draped over 30m hill-shade generated ASTER GDEMv2. The mapping revealed different types of landslides, and also revealed a considerable number of old, dormant landslide features. The use of wind-driven rainfall with integrated rainfall and aspect rasters provided a much more detailed and asymmetric distribution of precipitation. Spatial distribution of the very high and high hazard areas, during the Kermit and Belg rainy seasons by a range of 0.38% for an inclination of 40º and 1.7% for inclinations on 60º, as compared to the traditional assumption of 90º vertical rainfall, without integration of a slope aspect raster --Abstract, page iii
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