Spatial and temporal variation of surface radiation balance in an area of the Southern Amazonas, Brazil/Variacao espacial e temporal do saldo de radiacao superficial em uma area do sul do Amazonas, Brasil

The south of the Amazon has several natural vegetation types that are being replaced by agriculture. The spatial variation in the radiation balance is strongly related to land use change. Thus, the aim of this study was to evaluate the spatial and temporal variation of the net radiation on different...

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Published in:Ra'e ga 2016-08 (37), p.333
Main Authors: Pavao, Vagner Marques, Querino, Carlos Alexandre Santos, Beneditti, Cristina Aparecida, Pavao, Larissa Leite, Querino, Juliane Kayse Albuquerque da Silva, Machado, Nadja Gomes, Biudes, Marcelo Sacardi
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Language:Spanish
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Summary:The south of the Amazon has several natural vegetation types that are being replaced by agriculture. The spatial variation in the radiation balance is strongly related to land use change. Thus, the aim of this study was to evaluate the spatial and temporal variation of the net radiation on different surfaces in southern Amazonas state using Thematic Mapper (TM) Landsat 5 images. The study area was the Humaita-AM municipal area where were identified forest, grassland, grassland with shrub and city area. The images were acquired on the site of the US Geological Survey referring to the days 15/07/2009 and 02/07/2010. The Normalized Difference Vegetation Index (NDVI), Adjusted Vegetation Index to Soil (SAVI) and the surface net radiation (Rn) were calculated in the intermediate stages of SEBAL (Surface Energy Balance Algorithms for Land). The highest values of NDVI and SAVI were observed in forest areas, followed by grassland, grassland with shrub and city areas. The Rn positively related with NDVI and SAVI. The Rn ranged between 550 and 565 W [m.sup.-2] in the forest, 520 and 530 W [m.sup.-2] in grassland and grassland with shrub and below 500 W [m.sup.-2] in the urban area of Humaita. Therefore, it was found that the density of vegetation is a determining factor in the availability of energy in the environment. Keywords: land use; Amazon forest; energy exchanges; soil-plant-atmosphere interaction. O sul do Amazonas apresenta diversas fisionomias vegetais naturais que estao sendo substituidas pela agropecuaria. A variacao espacial no balanco de radiacao e fortemente relacionada a alteracoes no uso do solo. Sendo assim, o objetivo desse trabalho foi avaliar a variacao espaco-temporal do saldo de radiacao sobre diferentes superficies no sul do estado do Amazonas por imagens Thematic Mapper (TM) Landsat 5. A area de estudo foi no municipio de Humaita-AM, onde foi possivel identificar area de floresta, campo limpo, campo sujo e area de cidade. As imagens foram adquiridas no site do U. S. Geological Survey referentes aos dias 15/07/2009 e 02/07/2010. O Indice de Vegetacao da Diferenca Normalizada (NDVI), o Indice de Vegetacao Ajustado ao Solo (SAVI) e o Saldo de Radiacao da superficie (Rn) foram calculados nas etapas intermediarias do SEBAL (Surface Energy Balance Algorithms for Land). Os maiores valores de NDVI e SAVI foram observados em areas de floresta, seguido pelas areas de campo sujo, campo limpo e cidade. O Rn relacionou positivamente com NDVI e SAVI. O Rn
ISSN:1516-4136