Banca de DEFESA: SUELEN DA COSTA FARIA MARTINS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : SUELEN DA COSTA FARIA MARTINS
DATA : 20/03/2019
HORA: 10:00
LOCAL: Instituto de Tecnologia - Universidade Federal Rural do Rio de Janeiro
TÍTULO:

Actual evapotranspiration by the energy balance method - Bowen ratio in pasture area in the metropolitan region of Rio de Janeiro

PALAVRAS-CHAVES:

energy fluxes, FAO-56, seasonality

PÁGINAS: 67
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Agrometeorologia
RESUMO:

Evapotranspiration (ET) is, basically, the process of soil water evaporation added to the vegetation transpiration. Evapotranspiration estimation is extremely important to have a suitable irrigation management, for instance. There are some types of evapotranspiration, and for the current study, the actual evapotranspiration for a surface which is covered by pasture was chosen to work with, due to the fact that in the actual evapotranspiration it is taken into consideration the real conditions of the soil-plant-atmosphere system, if the plant is under water stress or not, for example. This study was developed in an experimental area, located in “Reserva Ecológica de Guapiaçu”, in Cachoeiras de Macacu, Rio de Janeiro. To estimate the actual evapotranspiration, the Energy Balance – Bowen Ratio method was used and it was compared to the reference evapotranspiration (ETo), estimated using the method by Penman-Monteith, the standardized method by FAO-56. Bowen Ratio has been used in various researches and it may be applied in many different types of surfaces, such as lakes, lagoons, to recharge aquifers and in forest pasture and crop evapotranspiration. ETo estimated by Penman-Monteith FAO-56 may also be applied to different types of vegetation and it has simple application. To make use of these methods, a micrometeorological mast was installed in the area, where measures of temperature and relative humidity profiles were made in three different high levels on the surface, wind speed profile in four different levels on the surface and of the net radiation. Moreover, measures of soil heat flux were also made. The instruments used for these measures were connected to an automated system of data acquisition, which collects and records the data. The main objectives of this study were to estimate and to evaluate the actual evapotranspiration by the Bowen Ratio method and the reference evapotranspiration by Penman-Monteith and to compare their results. The Bowen Ratio method generates errors due to the simplifications made to apply it, and in the level 2-3 it was verified high frequency of the error generated by the lack of temperature and relative humidity gradient, not being considered in other analyses. Energy fluxes partitions analyses were made and significant determination coefficients were found (r2 equal to 0.9947 to the latent heat flux and 0.9832 to the sensible heat). It was concluded that the latent heat flux increased in spring and in the summer, as well as the actual evapotranspiration and the reference evapotranspiration, period of the year when the water and solar energy availabilities are higher in the environment. Besides, both methods showed satisfactory performances, confirming that the needed measures to apply the Bowen Ratio method were made inside the inner boundary layer.

MEMBROS DA BANCA:
Presidente - 1574025 - GUSTAVO BASTOS LYRA
Externo ao Programa - 3040039 - MARCEL CARVALHO ABREU
Externo à Instituição - LUIS MARCELO DE MATTOS ZERI