Estudo do balanço de radiação à superfície no bioma caatinga com diferentes densidades.

Abstract

Arid and semiarid biomes are present in 40% of the Earth’s surface. In these places, the use of water and natural resources are essential for the development of plants and all the biomass in these ecosystems. In Brazil, the caatinga, present in most of the Northeast and in the north of the state of Minas Gerais, represents this type of biome, being this the most populated dry region in the world. Research on the fluxes and radiation balance in this region is still scarce, despite the relevance they have in areas such as agriculture and hydrology. In this study, through the analysis of data collected in micrometeorological stations from 2014 to 2016 in the cities of Campina Grande-PB, in areas with recovering (CR) and degraded (CD) caatinga vegetation and Serra Negra do Norte-RN , at the Seridó Ecological Station (ESEC-Seridó), where there is a preserved caatinga vegetation (CP), it was observed that, as well as the solar radiation reflected by the surface, the greatest fluxes of solar radiation incident on the surface occurred in the CD. Regarding the longwave radiation emitted by the surface (Rlu) and the atmosphere (Rld), the most intense fluxes occurred in the CP, following the association with the region’s air temperatures, which were much higher than in the other regions. The net Radiation (Rn) was greater in CD, followed by CP, and CR. Some adjusted models capable of estimating the Rld for the conditios of clear sky (Rcl) and cloudness for the two regions were obtained to estimate the Rn at the surface for the area of each one of the stations, having all these present satisfactory efficiency.