Soil sealing occurs as a result of the development of housing, industry, transport and other physical infrastructure, including utilities (e.g. waste disposal and water distribution) and military installations, i.e. as a result of the wider process of land consumption.
Since several years the European Commission has been promoting the monitoring of the built-up area spreading inside the Global Monitoring for Environment and Security (GMES) program, expoliting remote sensing technologies. In 2008, the first pan-European dataset of built-up areas and the degree of soil sealing was delivered covering 5.8 million square kilometers spanning 38 countries. In 2009, the European Environment Agency (EEA) requested that the Seventh Framework Programme (FP7)-funded geoland2 (www.gmes-geoland.info/) project update the built-up and imperviousness layers. Requested output products include updated status maps and change maps of the built-up area, status and change maps of imperviousness in 20-meter resolution and an updated one-hectare “European layer” of built-up areas and degrees of imperviousness.
The 2010 update was performed by many of the same members of the European consortium that created the base map for 2006, including Planetek Italia (Italy). Planetek Italia has provided a service for sealed area extraction (including buildings, roads and infrastructure) over several European Countries: Italy, Malta, Cyprus, Albania, Greece, West Turkey and Macedonia. At the beginning of year 2012 the EEA awarded the contract to Planetek Italia to map high-resolution Forest and Impervious Area characteristics in Southern Europe (West and Central Mediterranean region) in the framework of the GMES Initial Operations (GIO) Land Monitoring Services.
Due to the very large extent of the european area to be investigated, the strategy was to develop highly automated update tools that can be applied minimizing the level of operator interaction required. The automated workflow was specifically designed to be easily shared, which was especially important in this case, since the same methodology were applied by all production partners throughout Europe. For this reasons, the built-up and sealing update layers were generated with models built specifically for the project using the Model Maker in ERDAS IMAGINE. The Model Maker is a smart tool that enables users to develop models as graphical flow charts. The graphical models are translated into and run via the ERDAS Spatial Modeler Language (SML), a script language specially designed for GIS modelling and image processing applications (www.uwf.edu/gis/manuals/SML.pdf). The high degree of automation and the uniform methodology applied by the consortium members ensured a spatially consistent update product.