Using volunteered geographical information to map the November 2012 floods in Slovenia

Abstract

Abstract. Volunteered geographical information represents a promising field in the monitoring and mapping of natural disasters. The contributors of volunteered geographical information have the advantage that they are at the location of the natural disaster at exactly the time when the disaster happened. Therefore, they can provide the most complete account of the extent of the damage. This is not always possible when applying photogrammetric or remote-sensing methods, as prior to the data acquisition an order to carry out the measurements has to be made. On 5 and 6 November 2012 almost half of Slovenia was badly affected by floods. The gathering of volunteered geographical information in the form of images and videos of these floods is presented. Two strategies were used: (1) a public call for volunteered contributions and (2) a web search for useful images and their authors. The authorship of these images was verified with every contributor. In total, 15 contributors provided 102 terrestrial and aerial images and one aerial video, with 45 % classified as potentially useful. For actual flood mapping 22 images and 12 sequences from video were used. With the help of the volunteered images 12 % of the most severely affected river sections were mapped. Altogether, 1195.3 ha of flooded areas outside of the usual river beds along a total river length of 48 km were mapped. The results are compared with those from satellite mapping of the same floods, which successfully covered 18 % of the most affected river sections.

Reproducing an extreme flood with uncertain post-event information

“…Data from more events could further reduce the predictive uncertainties and help us to learn from the flow behaviour at some localized areas where the errors were large. Post-event estimates in the future could likely also come from social-media information which is becoming gradually more available (Fraternali et al, 2012;Triglav-Čekada and Radovan, 2013).…”

Development of a spatial decision support system for flood risk management in Brazil that combines volunteered geographic information with wireless sensor networks

“…This type of information, called Volunteered Geographic Information, has been of great practical value to complement existing geospatial datasets (Goodchild, 2007), owing to the potentially large number of volunteers who act as "sensors" (Poser and Dransch, 2010). In recent natural disasters, VGI has been used to support the activities of emergency agencies and government departments (Poser and Dransch, 2010;Yates and Paquette, 2011;Roche et al, 2011;Kongthon et al, 2012;Kaewkitipong et al, 2012;Triglav-Čekada and Radovan, 2013;Chae et al, 2014).…”

Environmental livelihood security in Southeast Asia and Oceania: a water-energy-food-livelihoods nexus approach for spatially assessing change. White paper

“…In the context of sustainable environmental livelihoods in the SAO region, VGI offers the opportunity for intelligent observers with diverse local knowledge to contribute reports in near-real time in-situ, without the disadvantages of other forms of technology, such as the costs associated with satellite or aerial imagery, issues of scale, or the impacts of cloud cover or weather and satellite imagery (see Triglav-Čekada and Radovan 2013). In the case of natural disasters, VGI provides a timely and cost-effective method for creating and disseminating relevant geographic information through two-way communication mechanisms facilitated between individuals, communities and authorities (see Goodchild and Glennon 2010;McDougall 2011).…”

“…There are important challenges to consider with the use of VGI, including issues of data quality, accuracy and reliability, trust and reliability of data and data sources, security and liability, bias in reports, data management, and the notion of the digital divide, or those without means or access to technologies potentially being excluded or marginalized (see Chinn and Fairlie 2007;Flanagin and Metzger 2008;Goodchild and Glennon, 2010;Zook et al 2010;Ostermann and Spinsanti 2011;Gao et al 2011;Purves 2011;Elwood et al 2012;Goodchild and Li 2012;Triglav-Čekada and Radovan 2013;Scassa 2013). But overall, with these considerations in mind, VGI provides an exciting opportunity to harness the existing dense network of observers and local knowledge to address a range of questions and issues across the environmental livelihoods sphere, and further research is needed to understand and detail potential applications and impacts (both positive and negative).…”