A Web GIS-Based Platform to Harvest Georeferenced Data from Social Networks: Examples of Data Collection Regarding Disaster Events

Whenever disaster situations occur the civil protection authorities need to have fast access to data that may help to plan emergency response. To contribute to the collection and integration of all available data a platform that aims to harvest Volunteered Geographical Information (VGI) from social networks and collaborative projects was created. This enables the integration of VGI with data coming from other sources, such as data collected by physical sensors in real time and made available through Applications Programming Interface (APIs), as well as, for example, official maps. The architecture of the created platform is described and its first prototype presented. Some example queries are performed and the results are analyzed

Thematic Comparison between ESA WorldCover 2020 Land Cover Product and a National Land Use Land Cover Map

Duarte, D., Fonte, C., Costa, H., & Caetano, M. (2023). Thematic Comparison between ESA WorldCover 2020 Land Cover Product and a National Land Use Land Cover Map. Land, 12(2), 1-16. [490]. https://doi.org/10.3390/land12020490 --- Funding: This work has been supported by projects foRESTER (PCIF/SSI/0102/2017), SCAPEFIRE (PCIF/MOS/0046/2017) and FireLoc (PCIF/MPG/0128/2017), by Centro de Investigação em Gestão de Informação (MagIC) and grant UIDB/00308/2020, all funded by the Portuguese Foundation for Science and Technology (FCT). It was also supported by Compete2020 (POCI-05-5762-FSE-000368), funded by the European Social Fund.This work presents a comparison between a global and a national land cover map, namely the ESA WorldCover 2020 (WC20) and the Portuguese use/land cover map (Carta de Uso e Ocupação do Solo 2018) (COS18). Such a comparison is relevant given the current amount of publicly available LULC products (either national or global) where such comparative studies enable a better understanding regarding different sets of LULC information and their production, focus and characteristics, especially when comparing authoritative maps built by national mapping agencies and global land cover focused products. Moreover, this comparison is also aimed at complementing the global validation report released with the WC20 product, which focused on global and continental level accuracy assessments, with no additional information for specific countries. The maps were compared by following a framework composed by four steps: (1) class nomenclature harmonization, (2) computing cross-tabulation matrices between WC20 and the Portuguese map, (3) determining the area occupied by each harmonized class in each data source, and (4) visual comparison between the maps to illustrate their differences focusing on Portuguese landscape details. Some of the differences were due to the different minimum mapping unit ofCOS18 and WC20, different nomenclatures and focuses on either land use or land cover. Overall, the results show that while WC20 detail is able to distinguish small occurrences of artificial surfaces and grasslands within an urban environment, WC20 is often not able to distinguish sparse/individual trees from the neighboring cover, which is a common occurrence in the Portuguese landscape. While selecting a map, users should be aware that differences between maps can have a range of causes, such as scale, temporal reference, nomenclature and errors.publishersversionpublishe

Perspectives on “Earth Observation and GIScience for Agricultural Applications”

Current and future scenarios for global agricultural systems under a changing climate require innovative approaches, novel datasets, and methods for improving environmental resource management and better data-driven decision-making [...

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

Assessing OSM Road Positional Quality With Authoritative Data

Online collaborative mapping projects, such as OpenStreetMap (OSM), have been developed not only to provide public and free information about many types of geospatial features, including communication and transportation networks such as roads, trails and railways, but also to give its users the chance to contribute with their local knowledge about the places. There must be, however, a special concern for the quality assurance within these community driven maps. The aim of this paper is to assess the positional differences between the road network available in OSM for some regions of the Coimbra Municipality, Portugal, and the data provided by the Coimbra City Hall, considered as reference. The assessment is made by computing the distance between the features’ lines, extracted from OSM and the reference data, using two approaches. One regards the application of a workflow, which uses tools already available in GIS software. The other approach applies directly the FOSS4G-based procedure developed by Brovelli et al. (2015)

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)"

Investigating the feasibility of geo-tagged photographs as sources of land cover input data

Geo-tagged photographs are used increasingly as a source of Volunteered Geographic Information (VGI), which could potentially be used for land use and land cover applications. The purpose of this paper is to analyze the feasibility of using this source of spatial information for three use cases related to land cover: Calibration, validation and verification. We first provide an inventory of the metadata that are collected with geo-tagged photographs and then consider what elements would be essential, desirable, or unnecessary for the aforementioned use cases. Geo-tagged photographs were then extracted from Flickr, Panoramio and Geograph for an area of London, UK, and classified based on their usefulness for land cover mapping including an analysis of the accompanying metadata. Finally, we discuss protocols for geo-tagged photographs for use of VGI in relation to land cover applications

Mapping and the Citizen Sensor

The role of citizens in mapping has evolved considerably over the last decade. This chapter outlines the background to citizen sensing in mapping and sets the scene for the chapters that follow, which highlight some of the main outcomes of a collaborative programme of work to enhance the role of citizens in mapping

Considerations of Privacy, Ethics and Legal Issues in Volunteered Geographic Information

International audienceToday almost any kind of User Generated Content (UGC) can be situated within a geographic context. Volunteered Geographic Information (VGI) can include many types of UGC, such as georeferenced photographs, social media and text, geographic data themselves, etc. There are legal, privacy and ethical issues raised by VGI, and at present these are not very well studied or understood despite the rise in popularity of VGI. This chapter will discuss, investigate and define some 120 Mapping and the Citizen Sensor of the most prominent issues related to the legal, privacy and ethics topic within VGI. The chapter argues that these issues are not well understood by all of the actors in VGI, and in particular by the producers of this information as well as the users or consumers of this new data source. Creating a better understanding of these issues will be very important in the future development and evolution of VGI in society