Fluxo de calor no solo e radiação líquida em pastagem de capim braquiária com grau de cobertura variável

Abstract

The soil heat flux on the ground (G) is an important component of the energy balance and refers to the amount of thermal energy transferred to lower soil levels for unit area during a given period of time. The use of heat flow plates in the soil is widely used in several studies involving energy balance and water demand. The objective of this study was to evaluate the performance of models of heat flow plates in soil HFT3.1 (Radiation and Energy Balance Systems, Seattle, Washington, USA) and HFP01 (Hukseflux, Thermal, Delft, Netherlands) called REBS and HUKS respectively. In addition, the study aimed to find a ratio of net radiation (Rn) and soil coverage degree to estimate the heat flux in the soil in vegetated surface for braquiária grass. An automatic weather station was installed on the campus of the Federal University of Bahia Reconcavo - UFRB in the city of Cruz das Almas to obtain the data of soil variables and atmosphere for the study. The heat flux plates exhibited similar performance when compared within the same model as well as models of different manufacturers, it is possible to estimate the huKS values based on the values REBS. It was observed that the ratio L / Rn suffered interference degree of ground cover, being represented by L 23, 12, and 1% to Rn bare soil, partially covered and wholly covered. Thus, was obtained in these studies, models mathematically with high coefficient of determination (R²).