ANDRADE, S. C. P.; http://lattes.cnpq.br/5086189027878863; ANDRADE, Silvia Cristina de Pádua.
Resumen:
This study aimed to estimate the components of the energy balance at the surface and
quantify the impact of the replacement of forest by pasture areas in the flow of energy in
the state of Rondônia, Brazil. We used the algorithm METRIC (Mapping
Evapotranspiration at High Resolution and with Internalized Calibration) and ten
MODIS images that are aboard the Terra satellite was used meteorological elements
available in Deployed microteorológicas towers in forest and grassland sites , such as
wind speed and air temperature. The results showed a good agreement between the
values estimated by the satellite images with the measured data in micrometeorological
towers to the net radiation Rn, with an average percentage error of 13 % for the region
of grasslands and 9% for the forest area. It was found also that during the study period
there was an increase in sensible heat flux and soil heat , and a decrease in net radiation
, the latent heat flux and hence the instantaneous hourly evapotranspiration, which
affects considerably the local atmosphere , making it warmer and drier . The conversion
of forests to pasture caused significant changes in the radiation balance. The increase in
albedo values, the long-wave radiation emitted to the atmosphere and net longwave
radiation, resulted in a reduction of net radiation and evapotranspiration.