3,296 research outputs found
Seeing the invisible: from imagined to virtual urban landscapes
Urban ecosystems consist of infrastructure features working together to provide services for inhabitants. Infrastructure functions akin to an ecosystem, having dynamic relationships and interdependencies. However, with age, urban infrastructure can deteriorate and stop functioning. Additional pressures on infrastructure include urbanizing populations and a changing climate that exposes vulnerabilities. To manage the urban infrastructure ecosystem in a modernizing world, urban planners need to integrate a coordinated management plan for these co-located and dependent infrastructure features. To implement such a management practice, an improved method for communicating how these infrastructure features interact is needed. This study aims to define urban infrastructure as a system, identify the systematic barriers preventing implementation of a more coordinated management model, and develop a virtual reality tool to provide visualization of the spatial system dynamics of urban infrastructure. Data was collected from a stakeholder workshop that highlighted a lack of appreciation for the system dynamics of urban infrastructure. An urban ecology VR model was created to highlight the interconnectedness of infrastructure features. VR proved to be useful for communicating spatial information to urban stakeholders about the complexities of infrastructure ecology and the interactions between infrastructure features.https://doi.org/10.1016/j.cities.2019.102559Published versio
Interactive visual exploration of a large spatio-temporal dataset: Reflections on a geovisualization mashup
Exploratory visual analysis is useful for the preliminary investigation of large structured, multifaceted spatio-temporal datasets. This process requires the selection and aggregation of records by time, space and attribute, the ability to transform data and the flexibility to apply appropriate visual encodings and interactions. We propose an approach inspired by geographical 'mashups' in which freely-available functionality and data are loosely but flexibly combined using de facto exchange standards. Our case study combines MySQL, PHP and the LandSerf GIS to allow Google Earth to be used for visual synthesis and interaction with encodings described in KML. This approach is applied to the exploration of a log of 1.42 million requests made of a mobile directory service. Novel combinations of interaction and visual encoding are developed including spatial 'tag clouds', 'tag maps', 'data dials' and multi-scale density surfaces. Four aspects of the approach are informally evaluated: the visual encodings employed, their success in the visual exploration of the clataset, the specific tools used and the 'rnashup' approach. Preliminary findings will be beneficial to others considering using mashups for visualization. The specific techniques developed may be more widely applied to offer insights into the structure of multifarious spatio-temporal data of the type explored here
Visualization of uncertainty in natural hazards assessments using an interactive cartographic information system
Natural hazard assessments are always subject to uncertainties due to missing knowledge about the complexity of hazardous processes as well as their natural variability. Decision-makers in the field of natural hazard management need to understand the concept, components, sources, and implications of existing uncertainties in order to reach informed and transparent decisions. Until now, however, only few hazard maps include uncertainty visualizations which would be much needed for an enhanced communication among experts and decision-makers in order to make informed decisions possible. In this paper, an analysis of how uncertainty is currently treated and communicated by Swiss natural hazards experts is presented. The conducted expert survey confirmed that the communication of uncertainty has to be enhanced, possibly with the help of uncertainty visualizations. However, in order to visualize the spatial characteristics of uncertainty, existing uncertainties need to be quantified. This challenge is addressed by the exemplary simulation of a snow avalanche event using a deterministic model and quantified uncertainties with a sensitivity analysis. Suitable visualization methods for the resulting spatial variability of the uncertainties are suggested, and the advantages and disadvantages of their implementation in an interactive cartographic information system are discusse
Effect of Geospatial Uncertainty Borderization on Users' Heuristic Reasoning
Abstract. A set of mental strategies called "heuristics" – logical shortcuts that we use to make decisions under uncertainty – has become the subject of a growing number of studies. However, the process of heuristic reasoning about uncertain geospatial data remains relatively under-researched. With this study, we explored the relation between heuristics-driven decision-making and the visualization of geospatial data in states of uncertainty, with a specific focus on the visualization of borders, here termed "borderization". Therefore, we tested a set of cartographic techniques to visualize the boundaries of two types of natural hazards across a series of maps through a user survey. Respondents were asked to assess the safety and desirability of several housing locations potentially affected by air pollution or avalanches. Maps in the survey varied by "borderization" method, background color and type of information about uncertain data (e.g., extrinsic vs. intrinsic). Survey results, analyzed using a mixed quantitative-qualitative approach, confirmed previous suggestions that heuristics play a significant role in affecting users' map experience, and subsequent decision-making
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Introduction: Creating new worlds out of old texts
Despite initial expectations that globalization would eradicate the need for geographical space and distance, "maps matter" today in ways that were unimaginable a mere two decades ago. Technological advances have brought to the fore an entirely new set of methods for representing and interacting with spatial formations, while the ever-increasing mobility of ideas, capital, and people has created a world in which urban and regional inequalities are being heightened at an accelerating pace. As a result, the ability of any given place to reap the benefits of global socio-technical flows mainly hinges on the forging of connections that can transcend the limits of its material location. In contrast to the traditional "topographic" perspective, the territorial extent of economic and political realms is being increasingly conceived through a "topological" lens: as a set of overlapping reticulations in which the nature and frequency of links among different sites matter more than the physical distances between them.
At the same time, a parallel stream of innovation has revolutionized the understanding of space in disciplines such as history, archaeology, classics, and linguistics. Much of this work has been concentrated in the burgeoning field of the "digital humanities", which has been persistently breaking new ground in the conceptualization of past and present places. When seen in the context of globalization-induced dynamics, such developments emphasize the need for developing cartographic approaches that can bring out the inherently networked structure of social space via a lens that is both theoretically integrative and heuristically sharp.
We have decided to respond to these analytical and methodological challenges by focusing on ancient Greek literature: a corpus of work that has often been characterized as being free of the constraints imposed by post-Enlightenment cartography, despite setting the foundations of many contemporary map-making methods. In the 12 chapters that follow, we highlight the rich array of representational devices employed by authors from this era, whose narrative depictions of spatial relations defy the logic of images and surfaces that dominates contemporary cartographic thought. There is a particular focus on Herodotus' Histories - a text that is increasingly taken up by classicists as the example of how ancient perceptions of space may have been rather different to the cartographic view that we tend to assume. But this volume also considers the spatial imaginary through the lens of other authors (e.g. Aristotle), genres (e.g. hymns), cultural contexts (e.g. Babylon), and disciplines (e.g. archaeology), with a view to stimulating a broad-based discussion among readers and critics of Herodotus and ancient Greek literature and culture more generally.
In fact, many of the disciplinary and conceptual perspectives explored here are at their inception, and have a more general relevance for the wider community of humanities and social science researchers interested in novel mapping techniques. The resulting juxtaposition of more "traditional", philological discussions of space with chapters dedicated to the exploration of new technologies may jar or appear uneven, especially since we have not set out to privilege one method over another. But it is through viewing these different approaches in the round and reading them alongside each other that, we maintain, we can best disrupt customary ways of thinking (and writing) about space and catch a glimpse of new possibilities
Cartograms for use in forecasting weather driven natural hazards
This study evaluates the potential of using cartograms to visualise, and aid interpretation of, forecasts of weather driven natural hazards in the context of global weather forecasting and early warning systems. The use of cartograms is intended to supplement traditional cartographic representations of the hazards in order to highlight the severity of an upcoming event. Cartogrammetric transformations are applied to forecasts of floods, heatwaves, windstorms and snowstorms taken from the European Centre for Medium-range Weather Forecasts (ECMWF) forecast archive. Key cartogram design principles of importance in standard weather forecast visualisation are tested in terms of the tasks needed to visualise and interpret the forecast maps. These design principles include the influence of spatial autocorrelation of the variable mapped, the minimum and maximum values of a variable, the value of the sea, the addition of geographic features and the geographic extent used. Results show that the utility of the cartograms is dependent on these design principles, but the optimal cartogram transformation is dependent on geographical features (such as coastlines) and forecast features (such as snowstorm intensity). The importance of forecaster familiarisation training is highlighted. It was found in particular that for highly spatially autocorrelated weather variables used in analysing several upcoming natural hazards such as 2m temperature anomaly, the visualisation of the distortion provides a promising addition to standard forecast visualisations for highlighting upcoming weather driven natural hazards
Visualizing Data Certainty: A Case Study Using Graduated Circle Maps
Several techniques have been proposed for displaying data certainty on maps, but few have been empirically tested for effectiveness. While it is important to make data certainty information easily accessible, the addition of such data should not unduly increase map complexity. Thus, it becomes important for cartographers to examine the available methods for displaying this aspect of metadata and to test each for its effectiveness. The focus of this study was the display of data certainty information on graduated circle maps. Four types of accuracy indicators were evaluated for their effectiveness in communicating data certainty information. Two were traditional accuracy indicators: reliability diagrams and legend statements. Two were bivariate in form, one using a value-size combination and the other mimicking the idea of focus by varying the line value of the graduated circles to suggest a fading of symbolization for least certain data. The study was designed to assess whether subjects could identify data certainty information on test maps, and evaluate how accurately and confidently they could extract and interpret both thematic and data certainty information. Mean accuracy and confidence rates were compared for maps using different accuracy indicators to evaluate their relative effectiveness. Results suggest that subjects had most difficulty identifying and extracting data certainty information using maps that employed legend statements. They were most successful when data certainty was wedded to thematic data on the map using the bivariate accuracy indicator that mimicked the concept of focus. Identification and extraction of thematic data values were not significantly affected by choice of accuracy indicator
Visualizations Out of Context: Addressing Pitfalls of Real-Time Realistic Hazard Visualizations
Realistic 3D hazard visualizations based on advanced Geographic Information Systems (GIS) may be directly driven by hydrodynamic and wind model outputs (e.g., ADCIRC, the ADvanced CIRCulation Model) and hazard impact modeling (e.g., predicting damage to structures and infrastructure). These methods create new possibilities for representing hazard impacts and support the development of near-real-time hazard forecasting and communication tools. This paper considers the wider implications of using these storm visualizations in light of current frameworks in the context of landscape and urban planning and cartography that have addressed the use of realistic 3D visualizations. Visualizations used outside of engagement processes organized by experts risk misleading the public and may have consequences in terms of feelings of individual self-efficacy or perception of scientists behind the visualizations. In addition to summarizing the implications of using these visualizations outside of recommended practices, a research agenda is proposed to guide the development of real-time realistic and semi-realistic visualizations for future use in hazard communication. Development of a clearer use-case for real-time visualization capabilities is an essential first step if such work is to continue
Off the Grid
Off the Grid explores the messy relationship between public and private perceptions of our urban spaces, especially the tensions created when lived experience runs up against the physical and conceptual networks of cities: street grids, construction tape, and property lines. Incorporating different modes of spatial representation, from cartographic diagrams to isometric illustrations and Renaissance perspectives, this exhibition examines the role drawing plays in how we conceptualize the divisions and definitions of everyday space. The drawings engage the often overlooked detritus of city life, from layers of old graffiti to overgrown dirt piles and unmoored electrical wiring, that complicate our understanding of how urban space is actually used. Drawn from the spaces surrounding the artist’s daily routine, Off the Grid investigates the potential of a subjective cartography to tell a more complete story about the places we inhabit
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