Radiation and Energy Fluxes in Preserved Caatinga and Sugarcane in Semi-Arid

Abstract The objective of this study was to compare the radiation and energy fluxes between an area of preserved caatinga and an irrigated sugarcane crop in the Brazilian semi-arid region. The radiation and energy components, the environmental data (soil moisture and temperature, water regime) and the vegetation cover index were analyzed between June 2015 and May 2016. In each area was installed a micrometeorological tower equipped with electronic sensors. As results, it was verified that the main differences in the radiation balance between caatinga and sugarcane are associated to the albedo and the emission of long-wave radiation on the surfaces. The sensible heat flux (H) was always higher in the caatinga, while the latent heat flux (LE) was higher in sugarcane (p < 0.05). In the caatinga, the energy partitions for H, LE and soil heat flux (G) were 64%, 34% and 2%, in that order; while in sugarcane, it was 12% for H, 85% for LE and 3% for G; with significant differences between the surfaces (p < 0.05). These differences can lead to modifications in the local and / or regional climate, so they should be considered in hydrological and climatic simulation models.