Voronoi-Based Region Approximation for Geographical Information Retrieval with Gazetteers

Gazetteers and geographical thesauri can be regarded as parsimonious spatial models that associate geographical location with place names and encode some semantic relations between the names. They are of particular value in processing information retrieval requests in which the user employs place names to specify geographical context. Typically the geometric locational data in a gazetteer are confined to a simple footprint in the form of a centroid or a minimum bounding rectangle, both of which can be used to link to a map but are of limited value in determining spatial relationships. Here we describe a Voronoi diagram method for generating approximate regional extents from sets of centroids that are respectively inside and external to a region. The resulting approximations provide measures of areal extent and can be used to assist in answering geographical queries by evaluating spatial relationships such as distance, direction and common boundary length. Preliminary experimental evaluations of the method have been performed in the context of a semantic modelling system that combines the centroid data with hierarchical and adjacency relations between the associated place names

A conceptual framework for studying collective reactions to events in location-based social media

Events are a core concept of spatial information, but location-based social media (LBSM) provide information on reactions to events. Individuals have varied degrees of agency in initiating, reacting to or modifying the course of events, and reactions include observations of occurrence, expressions containing sentiment or emotions, or a call to action. Key characteristics of reactions include referent events and information about who reacted, when, where and how. Collective reactions are composed of multiple individual reactions sharing common referents. They can be characterized according to the following dimensions: spatial, temporal, social, thematic and interlinkage. We present a conceptual framework, which allows characterization and comparison of collective reactions. For a thematically well-defined class of event such as storms, we can explore differences and similarities in collective attribution of meaning across space and time. Other events may have very complex spatio-temporal signatures (e.g. political processes such as Brexit or elections), which can be decomposed into series of individual events (e.g. a temporal window around the result of a vote). The purpose of our framework is to explore ways in which collective reactions to events in LBSM can be described and underpin the development of methods for analysing and understanding collective reactions to events

Using the Monoplotting Technique for Documenting and Analyzing Natural Hazard Events

Historical or present-day oblique terrestrial photographs documenting natural disasters are abundant in archives and may be easily taken nowadays. While in most cases they provide highly informative details, they can hardly be georeferenced, which prevents their systematic use for analyzing and documenting the events and any related signs of damage. In this chapter, we present a monoplotting software program developed at WSL (the WSL Monoplotting Tool) that allows the georeferencing of ordinary individual photographs in order to produce georeferenced vector data by drawing them directly on the photographs and exchanging them with traditional geographic information systems (GIS-Systems). We report on the application of the monoplotting tool on selected study cases of natural events or protection infrastructures in Switzerland

An Example from Switzerland

This article is based on comparative anthropological fieldwork conducted in the Alpine region of Switzerland on sustainable environmental knowledge about natural hazards related to climate change. It examines ways to complement the normative and technological practices of risk management by using local knowledge to improve the resilience of affected communities against climate- related risks. The study shows how agricultural practices and knowledge may contribute to sustainable behavior towards nature and the environment. It explores how local environmental knowledge, perceptions, and handling strategies of climate-related risks may be integrated within a renewed concept of environmental sustainability. Participatory GIS mapping (PGIS) is the primary research method used. Based on applied visual anthropological methods, PGIS is a cartographical approach that integrates local perceptions and strategies of action drawn from interviews and participant observation. This approach enables improved communication of local knowledge and contributes to interdisciplinary cooperation between different academic fields, such as social anthropology, geography, and civil-engineering in the context of technological risk management. The approach encourages the active participation of local people in the process of sustainable risk management through the integration of cultural meanings and local knowledge about the sustainable management of sensitive natural environments

Prototype to Increase Crosswalk Safety by Integrating Computer Vision with ITS-G5 Technologies

Human errors are probably the main cause of car accidents, and this type of vehicle is one of the most dangerous forms of transport for people. The danger comes from the fact that on public roads there are simultaneously different types of actors (drivers, pedestrians or cyclists) and many objects that change their position over time, making difficult to predict their immediate movements. The intelligent transport system (ITS-G5) standard specifies the European communication technologies and protocols to assist public road users, providing them with relevant information. The scientific community is developing ITS-G5 applications for various purposes, among which is the increasing of pedestrian safety. This paper describes the developed work to implement an ITS-G5 prototype that aims at the increasing of pedestrian and driver safety in the vicinity of a pedestrian crosswalk by sending ITS-G5 decentralized environmental notification messages (DENM) to the vehicles. These messages are analyzed, and if they are relevant, they are presented to the driver through a car’s onboard infotainment system. This alert allows the driver to take safety precautions to prevent accidents. The implemented prototype was tested in a controlled environment pedestrian crosswalk. The results showed the capacity of the prototype for detecting pedestrians, suitable message sending, the reception and processing on a vehicle onboard unit (OBU) module and its presentation on the car onboard infotainment system.info:eu-repo/semantics/publishedVersio