Land cover changes caused by humans have reached points never witnessed in history before. Consequences of these changes are environmental degradation, pollution of water, biodiversity loss and climate change among others. It is in this frame that the interest of the scientific community for this type of events has increased in the last decades. Nowadays, researchers have access to sophisticated monitoring tools and techniques. However, the new threat is that over abundance of information would hide relevant facts and processes. In our research we use data from the CORINE (Coordination of Information on the Environment) program. This program has compiled land cover information about Europe in a standardized form for the years 1990, 2000 and 2006, allowing comparative studies of land cover evolution. In this chapter we present the LC3 data model to study land cover changes. In our research we use Semantic Web technologies to create a formal representation of the CORINE land cover classification. Later we use the same technologies to create formal representations of the components involved in land cover change. In our research land cover types are organized as a taxonomy. Using this approach it is easy to aggregate and disaggregate land cover types at different levels, allowing a more flexible analysis. An additional benefit is that it is possible to create formal descriptions of particular land cover changes, allowing an easy identification of them at different levels of the land cover classification. Our approach has been implemented as a computer program using a triplestore as its data repository. Our approach enable scientist to easy discover patterns of change that could be hidden due to the large volumes of data.