Navegando por Autor "SOUSA, Francisco de Assis Salviano de"

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Acesso aberto (Open Access)
Modelagem da interceptação na Floresta Nacional de Caxiuanã, no Leste da Amazônia
(2008-09) OLIVEIRA, Leidiane Leão de; COSTA, Rafael Ferreira da; COSTA, Antonio Carlos Lôla da; SOUSA, Francisco de Assis Salviano de; BRAGA, Alan Pantoja
The present work was carried out in the Ferreira Penna Scientific Station, at the Caxiuanã National Forest in Melgaço, Pará, Brazil (01º 42’ 30” S; 51º 31’ 45” W; 60 m of altitude) in the Eastern Amazonia. It is an upland forest area with closed vegetation, 35 m average canopy high, some emergent trees with 50 m high and species density between 450 and 550 plants per hectare. The objective was to compare the estimations of rainfall interception using two numerical models, for the period from March to December of 2004. The measured rainfall interception was 248 mm corresponding to 21.5% of total precipitation (1,153.4 mm) above canopy. The rainfall interception was simulated, by Rutter´s and Gash´s models, at good level of accuracy. The Gash model overestimated the interception by 17.3% (42.8 mm), while the Rutter model overestimated by only 0.5% (1.1 mm) of the observed interception.
Acesso aberto (Open Access)
Precipitação efetiva e interceptação em Caxiuanã, na Amazônia Oriental
(Instituto Nacional de Pesquisas da Amazônia, 2008-12) OLIVEIRA, Leidiane Leão de; COSTA, Rafael Ferreira da; SOUSA, Francisco de Assis Salviano de; COSTA, Antonio Carlos Lôla da; BRAGA, Alan Pantoja
The present work was carried out at the Ferreira Penna Scientific Station, in the Caxiuanã National Forest, Melgaço, Pará, Brazil (01º 42" 30"S; 51º 31" 45"W; 60 m a.s.l.). The studied region is an upland forest with closed vegetation and a mean canopy height of 35 m although some trees can be 50 m high. The species density is between 450 and 550 plants per hectare. The aim was to quantify the net precipitation, throughfall, stemflow and rain interception by vegetation, from March to December of 2004. For the throughfall measurements 25 rain gauges were randomly distributed in an one hectare area subdivided in one hundred parcels of 10 x 10 m, while the stemflow was measured on seven trees with a stem diameter at breast height representative of the area. The results showed values of net precipitation of 905.4 mm, throughfall of 885.4 mm, stemflow 20 mm and rain interception of 248 mm,corresponding respectively to 78.5%, 76.8%, 1.7% e 21.5% of the total precipitation above the canopy which was 1,153.4 mm for the study period.