BALANÇO DE RADIAÇÃO EM ÁREAS DE EXPANSÃO AGRÍCOLA NO SUDOESTE DO PIAUÍ

Abstract

Agricultural areas have been intensifying in the State of Piaui, this development results in damage to native vegetation, causing environmental impacts. Studies that evaluate these impacts are extremely important to quantify the changes caused on the surface. Thus, the objective was to identify changes in soil cover and evaluate its impacts on the radiation balance, vegetation indices and surface temperature in an agricultural expansion area in southwest Piaui. The evaluated area is located in the municipality of Baixa Grande do Ribeiro, using images from the Landsat 5 TM and Landsat 8 satellites, obtained between the years 1990 and 2018. The Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), Albedo (α), Radiation Balance, Long Wave Radiation (ROLs) and Surface Temperature (Ts) were evaluated. A reduction of 32.25% in native vegetation and a growth of 1,219.1% in agricultural exploitation were identified. The natural vegetation of the Cerrado showed lower temperature, albedo and ROLs and a higher radiation balance, when compared to exposed soil areas. Agricultural exploration in the southwest of Piaui has been promoting changes in the region s natural vegetation, causing environmental impacts, promoting an increase in surface temperature and decreasing the availability of energy. It is necessary to carry out more work that provides more information on these changes and also on the performance of public policies for agricultural and environmental planning purposes.