Índices de vegetação no monitoramento espaço-temporal da cobertura da terra no município de Riacho de Santana – BA

Abstract

Riacho de Santana is a city located in the semi-arid region of the state of Bahia, characterized by vegetation of the Caatinga biome and being in the São Francisco basin. In this area could be seen intense changes due to the removal of vegetation, besides changes in the average amount of precipitation and the periodicity. In this context, the present work aims to determine the dynamics of land occupation and occupation in the municipality of Riacho de Santana in the years 1986, 2004 and 2017. This process used Remote Sensing techniques, directed to the study of vegetation. The vegetation indexes by normalized difference (NDVI) and the soil adjusted vegetation index (SAVI) were applied in the satellite images of LandSAT 5, TM sensor and LandSAT 8, OLI sensor. Was made TOA atmospheric correction, cropping of images and calculation of vegetation indexes. For the purposes of comparison, four indices was defined: water, exposed soil, undergrowth and woody vegetation. The results obtained with the indices (NDVI and SAVI) showed significant differences between the analyzed years, with emphasis on the reduction of the exposed soil and consequent increase of the undergrowth. These results indicate a change in the pattern of land occupation and new and ongoing monitoring fordiagnoses should be made, aiming more robust data.