The Alto Descoberto basin is an important water source for the Distrito Federal. During the past years, this basin has suffered an agriculture and urban expansion over the natural areas. The inadequate land use associated with a lack of planning the use and occupation of the land, can lead to alteration in the superficial water flow and hydrological cycle, to siltation, to pollution of the superficial and underground water bodies and also towards an unbalanced environment in the region. Because of that, the monitoring and analysis of land use and occupation are extremely needed in the prevention of these impacts and maintenance of the water bodies. Keeping that in mind, this study aimed to perform the mapping and comparative analysis of the land use and occupation of the soil of the Alto do Descoberto basin between 1994 and 2011. The classifications of use and occupation of the soil were elaborated using a classifier oriented to the fuzzy rulebased object, allowing the analysis of the advances of the soil use and loss of vegetal coverage of the basin. The classification system was considered successful, with thematic accuracy (Kappa index) of 0.64. Although there are still some thematic confusions during the classification process, the comparative analysis among theme classes of the maps of the referred years showed a strong agriculture expansion of the region in approximately 11% of the river basin area, as well as a loss of the natural vegetation.
Land use and occupation; Object-based classification; ENVI EX
