Jacinto Estima

Investigating the Potential of OpenStreetMap for Land Use/Land Cover Production: A Case Study for Continental Portugal

In the last decade, volunteers have been contributing massively to what we know nowadays as Volunteered Geographic Information (VGI). Through the research that has been conducted recently, it has become clear that this huge amount of information might hide interesting and rich geographical information. The OpenStreetMap (OSM) project is one of the most well-known and studied VGI initiatives. It has been studied to identify its potential for different applications. In the field of Land Use/Cover, an earlier study by the authors explored the use of OSM for Land Use/Cover (LULC) validation. Using the COoRdination of INformation on the Environment (CORINE) Land Cover (CLC) database as the Land Use reference data, they analyzed the OSM coverage and classification accuracy, finding an interesting global accuracy value of 76.7 % for level 1 land classes, for the study area of continental Portugal, despite a very small coverage value of approximately 3.27 %. In this chapter we review the existing literature on using OSM data for LULC database production and move this research forwards by exploring the suitability of the OSM Points of Interest dataset. We conclude that OSM can give very interesting contributions and that the OSM Points of Interest dataset is suitable for those classified as CLC class 1 which represents artificial surfaces.

Flickr Geotagged and Publicly Available Photos: Preliminary Study of Its Adequacy for Helping Quality Control of Corine Land Cover

Volunteered Geographic Information has become exponentially available over the Web in the last years. This availability can hide a vast geographical richness and provides us with both a great opportunity to explore new ways to use it and also big challenges related with its unstructured nature. In this paper we conduct a preliminary analysis of the adequacy of photos from the Flickr initiative in order to use them as a source of field data in the quality control of the Land Use/Cover databases production. We evaluate its temporal and spatial distributions over Continental Portugal and also its distribution over Land Use/Cover classes using as a reference the European Corine Land Cover database. We conclude that this source is very valuable but needs to be combined with other sources due to some issues related with its spatial distribution.

Photo Based Volunteered Geographic Information Initiatives: A Comparative Study of their Suitability for Helping Quality Control of Corine Land Cover

Volunteered Geographic Information has become exponentially available over the Web in the last years. This availability can hide a vast geographical richness and provides us with both a great opportunity to explore new ways to use it and also big challenges related with its unstructured nature. This paper conducts a preliminary analysis of the adequacy of photos from the Flickr and Panoramio initiatives in order to use them as a source of field data in the quality control of the Land Use/Cover databases production. It evaluates its temporal and spatial distributions over Continental Portugal and also its distribution over Land Use/Cover classes using as a reference the European Corine Land Cover database. It concludes that this source is very valuable but needs to be combined with other sources due to its uneven spatial distribution.