CHANGES IN THE VEGETATION COVER OF THE URUÇUÍ-UNA ECOLOGICAL STATION BETWEEN THE DRY AND RAINY SEASONS

Abstract

The Ecological Stations (ESEC) are conservation units in the category of Integral Protection, whose regulations are established by Federal Regulatory Law No. 9.985, of July 18, 2000. In Piauí, the only example of this type of conservation is the Uruçuí-Una ESEC, located in the southwest of the state, with an area of approximately 135,200 hectares preserving examples of vegetation typical of the Cerrado biome. This type of vegetation is characterized by the loss of its leaves during the dry season as a form of preservation, reducing the area of transpiration to survive long periods of drought, but this causes substantial changes in the local landscape. In order to quantify seasonal variations in vegetation, this study analyzed changes in the vegetation cover of the Uruçuí-Una ESEC, using the Normalized Difference Vegetation Index (NDVI). The results showed that changes in vegetation occurred in areas close to watercourses and in the valleys of the ESEC, with high NDVI values for the rainy season and low values for the dry season, which demonstrates the severe loss of leaf mass in the tree canopy. On the other hand, in the central area of the ESEC the vegetation underwent little significant change as it maintained the same NDVI values between the seasons.

Keywords: Ecological Station. NDVI. Landsat-8.