Spatial and temporal-time analysis of land use in part of the semi-arid region of Ceara State, Brazil

The vegetation cover plays a key role in protection and conservation of natural resources, particularly concerning soils. This study had as objective to analyze space and time dimensions of anthropic influence on the vegetation cover in part of the semi-arid region of the Ceara State, Brazil. LANDSAT TM-5 satellite images of 1985 and 1994 combined with geoprocessing techniques were used to verify the hypothesis of intensification of environmental degradation. Maps of the vegetation cover, land use, soils, and hydrography were elaborated. They pointed out to an increase in degraded areas of the different phytoecological units. During this decade, a progressive degradation process was verified in study areas of the Independ (e) over cap ncia, Pedra Branca, Mombaca and Taua counties The Pedra Branca areas suffered the least from degradation. Among all areas, the sparse arborous Caatinga was the most degraded ecological unit, triggering degradation and transformation processes in the neighboring units. A large part of the area under investigation was en viron mentally degraded, with a substantial reduction of biodiversity, besides an overall downsizing of vegetal formations.