Dynamics and degradation of pastures in the microregion of Goiânia through vegetation indices and satellite data

Abstract

The quality of pasture directly reflects on the productivity of meat, milk, and their derivatives, as well as the socio-environmental quality of a particular region. The assessment of pasture degradation in extensive areas can be conducted through vegetation indices obtained from sensors installed on orbiting satellites. This study aimed to understand the dynamics of pastureland in the Goiânia Microregion between the years 1985 and 2019, as well as to assess the quality of these pastures in 2019. Satellite images obtained from Mapbiomas for the years 1985, 1997, 2008, and 2019 were used to determine pasture areas by municipality. To assess pasture degradation, the average annual NDVI was obtained from Sentinel 2A satellite images with a resolution of 10 meters. A gradual reduction in pastureland area was observed in 15 out of the 17 municipalities in the Microregion during the study years. According to the average NDVI values in 2019, only 26% of the pasture area showed no degradation, while 44%, 22%, and 8% exhibited mild, moderate, and severe degradation, respectively. Sentinel 2A satellite images prove to be an efficient tool for assessing pasture degradation in the studied region.