A Guidance Tool for VGI Contributors

Many people are familiar with the VGI project OpenStreetMap (OSM), but there are many other projects that are not as well known to volunteers. What is needed is a tool that can help volunteers match their motivations, interests and background to appropriate types of VGI projects

VGI Quality

The poster summarizes the research works on Volunteered Geographic Information (VGI) quality undertaken within the EU COST Actions TD1202 "Mapping and the Citizen Sensor" and IC1203 "European Network Exploring Research into Geospatial Information Crowdsourcing: software and methodologies for harnessing geographic information from the crowd (ENERGIC)"

Online Map Services: Contemporary Cartography or a New Cartographic Culture?

In this paper, online map services are reviewed from a cartographic point of view. The most popular online map services are selected based on worldwide website traffic data, provided by specialized sites, such as Similarweb, in terms of global coverage and popularity among users. Online map services are commented based on cartographic principles, conventions and traditional practices addressing topics, such as: Cartographic projection, orientation, scale, marginalia, content (thematic layers), symbology, generalization, annotation, color use and overall map design. Color schemes utilized in web maps are discussed in more detail, since based on studies concerning the selection of the preferable map by experts and laymen, color is undisputedly the most frequently mentioned factor. It can be stated that online map services generally adopt well-known cartographic practices, which are not always applied as expected. Moreover, suggestions for the improvement of online map services are made regarding cartographic projection, legend, content, symbolization, color, etc

"A Methodology for the Assessment of Generalization Quality"

Generalization quality assessment is a major issue in contemporary cartography. Besides the evaluation of generalization results, it supports the research for the automation of generalization. In this paper, two methods, based on structure and shape recognition, are elaborated: the parametric description of line shape and the partitioning of linear features into homogeneous segments. A number of quantitative measures for the assessment of line shape change due to generalization are identified. These measures provide an “a posteriori” evaluation of generalization alternatives, which result from the application of different generalization operators (i.e. simplification, smoothing), algorithms and tolerance values, onto a number of linear features of varying degree of complexity. In combination with existing quantitative measures for the horizontal position error, these measures constitute an efficient approach for the positional accuracy assessment at the individual object level. Specific tools, like graphs and tables, are proposed for the study of the positional accuracy aspect of any generalization schema. The application of this methodology will lead to the formulation of criteria, which can be used for the selection of the most suitable generalization solution and subsequently to knowledge acquisition and the development of a knowlwdge base to support automated map generalization. 1. Cartographic generalization and qualit

Volunteered geographic information use in crisis, emergency and disaster management: a scoping review and a web atlas

Nowadays, an increasing number of crises worldwide, triggered by climate extremes, natural and human-made hazards, the coronavirus pandemic, and more, pose a high pressure on crisis, emergency, and disaster management. Spatial data and Volunteered Geographic Information (VGI) are key issues in the successful and immediate response to crises. This paper aims to explore the use of VGI in crisis management, including emergency and disaster management, based on a scoping review of existing literature in English for five years (2016–2020). Specifically, the research intends to answer Scoping Review Questions (SRQ) regarding the use of VGI in crisis, emergency, and disaster management, and the verified cases’ spatial distribution, the VGI sources utilized (e.g. OpenStreetMap – OSM, Crowdsourcing, Twitter), the types of hazards (e.g. natural and human-made hazards, pandemic), the specific tasks in crisis, emergency or disaster management and VGI use in the management of actual crisis events, e.g. COVID-19 pandemic, Hurricane Katrina, etc. Eligible papers on VGI use in crisis, emergency, and disaster management are geolocated based on first-author affiliation, and as a result, a spatial bibliography is provided. Thus, the term Spatial Scoping Review is introduced. Scoping Review Questions are answered, and the results are analyzed and discussed. Finally, implementing the “VGICED Atlas”, a web atlas, permits the publication of the research results to a broad audience and the visualization of the analysis with several interactive maps

Production of Topographic Maps with VGI: Quality Management and Automation

International audienceThe most common way to use geographic information is to make maps. With the ever growing amount of Volunteered Geographic Information (VGI), we have the opportunity to make many maps, but only automatic cartography (generalisation, stylisation, text placement) can handle such an amount of data with very frequent updates. This chapter reviews the recent proposals to adapt the current techniques for automatic cartography to VGI as the source data, focusing on the production of topographic base maps. The review includes methods to assess quality and the level of detail, which is necessary to handle data heterogeneity. The paper also describes automatic techniques to general-ise, harmonise and render VGI

Generalization of Soundings across Scales: From DTM to Harbour and Approach Nautical Charts

This paper presents an integrated digital methodology for the generalization of soundings. The input for the sounding generalization procedure is a high resolution Digital Terrain Model (DTM) and the output is a sounding data set appropriate for portrayal on harbour and approach Electronic Navigational Charts (ENCs). The sounding generalization procedure follows the “ladder approach” that is a requisite for the portrayal of soundings on nautical charts, i.e., any sounding portrayed on a smaller scale chart should also be depicted on larger scale charts. A rhomboidal fishnet is used as a supportive reference structure based on the cartographic guidance for soundings to display a rhombus pattern on nautical charts. The rhomboidal fishnet cell size is defined by the depth range and the compilation scale of the charted area. Generalization is based on a number of rules and constraints extracted from International Hydrographic Organization (IHO) standards, hydrographic offices’ best practices and the cartographic literature. The sounding generalization procedure can be implemented using basic geoprocessing functions available in the most commonly used Geographic Information System (GIS) environments. A case study was performed in the New York Lower Bay area based on a high resolution National Oceanic and Atmospheric Administration (NOAA) DTM. The method successfully produced generalized soundings for a number of Harbour and Approach nautical charts at 10 K, 20 K, 40 K and 80 K scales

Using OSM, Geo-Tagged FLICKR Photos and Authoritative Data: A Quality Perspective

The appearance of OpenStreetMap (OSM) in 2004 sparked a phenomenon known as Volunteered Geographic Information (VGI). Today, VGI comes in many flavours (e.g. toponyms, GPS tracks, geo-tagged photos, micro-blogging or complete topographic maps) and from various sources. One subject that has attracted research interest from the early days of VGI is how good such datasets are and how to combine them with authoritative datasets. To this end, the paper explores three intertwined subjects from a quality point of view First, we examine the topo-semantic consistency of OSM data by evaluating a number of rules between polygonal and linear features and then paying special attention to quality of Points of Interest (POIs). A number of topo-semantic rules will be used to evaluate the valididy of features’ location. The focus then turns to the use of geo-tagged photos to evaluate the location and type of OSM data and to disambiguate topological issues that arise when different OSM layers overlap