Creating a green network
Among their tasks, the regions and municipalities are responsible for managing green areas. This involves maintaining and restoring existing green areas, creating new ones and managing their distribution throughout the territory to create what is known as a “green network”. Green areas in an urban environment play an essential role in terms of ecology (improvement of urban climate, buffer effect against air pollution, maintenance of biodiversity, hydrologic role), planning (aeration of a very dense fabric of urbanisation), recreation and education. However, monitoring land use is a laborious and painstaking task that makes heavy demands on time and energy. Moreover, the municipalities often lack the kind of detailed and up-todate maps of green areas that they have of the urban network or of built-up areas. This is why the techniques of Earth observation by satellite, and in particular the use of very high resolution images, are so promising in developing applications of use in studying green areas in an urban environment. This applied research was carried out by three scientifi c teams in partnership with a private company seeking to develop products with a high added value. Researchers worked closely with the managing authorities in the fi eld, that are the City of Ghent and the Brussels Institute for Environmental Management, the latter responsible for managing green areas in the Belgian capital.