Mapas de Atenuação e Acumulação
João Moura Pires (superv.), Universidade Nova de Lisboa, June 2016.
Keywords: Geovisual Analytics, Spatiotemporal Events, Spatiotemporal Evolution, Pattern Recognition, Cartographic Representation
Abstract: Some phenomena, such as crimes in a city, fires occurred in a country and road accidents (among many others) can be interpreted as sets of spatiotemporal events. A spatio-temporal event is a summarized representation of an occurrence happened in reality. Each event is described by a geographic location, a time instant and eventually by some other characterizing attributes. The cartographic visualization of these events remains a unresolved problem, due to the challenges that arise with dealing simultaneously with several dimensions: the spatial (2D or 3D), temporal and semantic (zero or more dimensions) phenomenon components. The geovisualization techniques proposed in literature for these kind of data, have distinct basic concepts and address problems with specific characteristics, which does not always allow them to be properly applied to space-time events. This creates the need for an approach that properly fits the majority of these events and which stands out as advantageous when applied to them. In this context, this thesis presents a new geovisualization analytic method: the Attenuation and Accumulation Maps (AA-Maps). The main idea of this approach consists in showing visually (in a map), the resulting effect of combining attenuation and accumulation, until that moment of observation. As a result, it will be possible to observe the event’s evolution through the effect decay produced by it, that occurs in the course of time. Ultimately, this analysis enhance the analyst’s cognitive capabilities, helping in the decision making process (detect patterns, identify tendencies, define hypothesis, etc.).