30,613 research outputs found

    Exploratory analysis of OpenStreetMap for land use classification

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    In the last years, volunteers have been contributing massively to what we know nowadays as Volunteered Geographic Information. This huge amount of data might be hiding a vast geographical richness and therefore research needs to be conducted to explore their potential and use it in the solution of real world problems. In this study we conduct an exploratory analysis of data from the OpenStreetMap initiative. Using the Corine Land Cover database as reference and continental Portugal as the study area, we establish a possible correspondence between both classification nomenclatures, evaluate the quality of OpenStreetMap polygon features classification against Corine Land Cover classes from level 1 nomenclature, and analyze the spatial distribution of OpenStreetMap classes over continental Portugal. A global classification accuracy around 76% and interesting coverage areas’ values are remarkable and promising results that encourages us for future research on this topic

    Using Geographic Information Science to Map the Flight of the Regicides in Seventeenth- century New England

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    In mid-seventeenth century two of the judges who condemned King Charles I of England to death became regicide fugitives when his son came to the throne as Charles II. The two men fled to New England and eluded their Royalist pursuers for twenty years. I am attempting to track their travels and hideouts through standard historical research and, more recently, the use of Geographic Information Science (GIS), a form of digital mapping technology which organizes information in a geographical format by adding spatial coordinates to existing data to form a geodatabase. This article describes the application of GIS to test an eighteenth-century historian’s description of the regicides’ movements in Connecticut during the spring and summer of 1661

    Toward user oriented semantic geographical information systems

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    User Oriented Geographical Information Systems, a recent adaptation of classical GIS concepts to everyday usage, are becoming more and more present in the web landscape. Recent developments show the need of adding higher semantic levels to the existing frameworks, to improve their usage, as well as to ease scalability. We point out limits of actual examples, related to handling heterogeneous data, scalability issues, and expressiveness, and suggest a framework for building a Semantic User Oriented GIS. Notably this framework aims to address the peculiarities of the geographical space domain, and to offer a cognitively sound interface to the user

    Assessing the suitable habitat for reintroduction of brown trout (Salmo trutta forma fario) in a lowland river : a modeling approach

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    Huge efforts have been made during the past decades to improve the water quality and to restore the physical habitat of rivers and streams in western Europe. This has led to an improvement in biological water quality and an increase in fish stocks in many countries. However, several rheophilic fish species such as brown trout are still categorized as vulnerable in lowland streams in Flanders (Belgium). In order to support cost-efficient restoration programs, habitat suitability modeling can be used. In this study, we developed an ensemble of habitat suitability models using metaheuristic algorithms to explore the importance of a large number of environmental variables, including chemical, physical, and hydromorphological characteristics to determine the suitable habitat for reintroduction of brown trout in the Zwalm River basin (Flanders, Belgium), which is included in the Habitats Directive. Mean stream velocity, water temperature, hiding opportunities, and presence of pools or riffles were identified as the most important variables determining the habitat suitability. Brown trout mainly preferred streams with a relatively high mean reach stream velocity (0.2-1m/s), a low water temperature (7-15 degrees C), and the presence of pools. The ensemble of models indicated that most of the tributaries and headwaters were suitable for the species. Synthesis and applications. Our results indicate that this modeling approach can be used to support river management, not only for brown trout but also for other species in similar geographical regions. Specifically for the Zwalm River basin, future restoration of the physical habitat, removal of the remaining migration barriers and the development of suitable spawning grounds could promote the successful restoration of brown trout
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