Estimativa do balanço de energia utilizando imagens TM - Landsat 5 e o algoritmo SEBAL no litoral sul de Pernambuco

Abstract

RESUMOAs trocas de energia na interface solo-planta-atmosfera, por meio das componentes do balanço de radiação (Rn) e dos fluxos de calor no solo (G), sensível (H) e latente (LE), são essenciais para a modelagem climática e hidrológica que, por sua vez, afetam toda a biosfera. Dessa forma, esta pesquisa teve por objetivos: (1) estimar e comparar o comportamento dos componentes do balanço de energia, usando o algoritmo SEBAL -Surface Energy Balance Algorithm for Land, em diferentes tipos de uso e cobertura do solo e (2) validar o algoritmo. Para isso, foram usadas três imagens TM -Landsat 5 de órbita e ponto 214/066, com datas de passagem em 26 de agosto de 2006, 6 de setembro de 2010 e 28 de janeiro de 2011, todas recortadas para enquadrar o litoral sul de Pernambuco. Os resultados mostraram a capacidade do SEBAL de estimar a variabilidade espacial dos diferentes componentes do balanço de energia, com capacidade de distinguir diferentes ocupações do solo. O cômputo do balanço de energia possibilita observar as formas diferenciadas do uso da energia pelos diferentes tipos de cobertura do solo e verificar aqueles que propiciam melhor conforto térmico. As estimativas da evapotranspiração obtidas pelo algoritmo SEBAL apresentaram uma boa concordância com os resultados obtidos pelo método da FAO-Penman-Monteith demonstrando, dessa forma, a potencialidade da abordagem metodológica escolhida. Palavras-chave: SEBAL, balanço de energia, evapotranspiração. ABSTRACT: ASSESSMENT OF ENERGY BALANCE USING TM -LANDSAT 5 DIGITAL IMAGES AND SEBAL ALGORITHM OVER THE SOUTHERN PERNAMBUCO SEACOASTThe energy exchange across soil vegetation-atmosphere interface through the net radiation components (Rn) the soil heat flux (G), sensible heat flux (H) and latent heat flux (LE) are of vital importance for the climatic and hydrologic modeling, which affects all biosphere. The main objectives of this research are: (1) to estimate and compare the several energy balance components behavior, using SEBAL algorithm, under different soil usages; and (2) to validate SEBAL algorithm. In order to make the analysis, three TM -Landsat 5 images, from orbit and point 214/066, the South Coast of Pernambuco State (Brazil) were used. The results showed the ability of SEBAL to estimate the spatial variability of the different components of energy balance, with the ability to distinguish different soil occupations. The calculation of the energy balance components allows to figure the different forms of energy usages by different soil coverage and to find those that provide better thermal comfort. Estimates of evapotranspiration obtained by the algorithm SEBAL showed a good agreement with the results obtained by the FAO-Penman-Monteith, thus demonstrating the potential of this methodological approach.

Three decades of reference evapotranspiration estimates for a tropical watershed in the eastern Amazon

“…The energy exchanges in the soil-vegetationatmosphere interface, which occur via the net radiation (Rn) and heat flux {soil (G), sensible (H), and latent (LE)} components, are essential for climate and hydrological modeling (Machado et al 2014). The latent heat flux (LE), which represents the loss of water from the surface in the form of vapor, can be converted into evapotranspiration (ET) …”

“…The determination of the energy balance on the Earth's surface involves two parts: the first consists of quantifying the net energy (Rn) of the fluxes of the shortwave and longwave radiation received and emitted by the surface, and the second part involves estimating the fluxes (G, H, and LE) from utilization of the net radiation available on the Earth's surface (Liu 2007, Machado et al 2014. The ETo can be quantified directly through lysimeter measurements or can be calculated indirectly using the energy balance approach (empirical models).…”

Procedures for calculation of the albedo with OLI-Landsat 8 images: Application to the Brazilian semi-arid

“…However, the model proposed by Zhong & Li (1988) employed by Bastiaanssen et al (1998) in the SEBAL (Surface Energy Balance Algorithm for Land) and initially applied to TM -Landsat 5 images, combines simplicity and precision. This model has been widely used in many studies on the balance of radiation (Silva et al, 2005b;Lopes et al, 2013;Gusmão et al, 2012), energy (Silva & Bezerra, 2006;Allen et al, 2007;Arraes et al, 2012;Bezerra et al, 2014;Machado et al, 2014;Mattar et al, 2014) and in researches analyzing alterations in land use and occupation (Rodrigues et al, 2009;Giongo et al, 2010;Oliveira et al, 2012).…”

Validation of the net radiation through sebal algorithm in different classes of land use and occupation in Rio de Janeiro

“…There was a predominance of vegetation in the main mountain ranges (Pedra Branca, Tijuca and Gericinó) existing in MRJ (GOULART et al, 2015), followed by high R n values in the evaluated dates. According to Machado et al (2014) and Caula et al, (2016), vegetation areas have lower albedo values, reflecting a smaller percentage of RS↓, followed by a lower loss by RL↓ due to having lower temperatures, favoring the energy availability in the form of net radiation. Lowland regions of MRJ are predominantly occupied with urban area and, consequently, there is little vegetation area (GOULART et al, 2015).…”

“…However, to improve the accuracy of SEBAL algorithm are necessary parameterization of several equations to better adjust it to the reality of the study area (BASTIAANSSE et al, 1998a;BASTIAANSSE et al, 1998b;ANDRADE et al, 2014;MACHADO et al, 2014;SILVA et al, 2014). This validation is performed by comparison between the estimated and obtained data in the field by onsite measurements of superficial energy flows or using empirical methods, such as PenmanMonteith method (FAO 56).…”