Surface albedo in different land-use and cover types in Amazon forest region

Abstract

Albedo is the portion of energy from the Sun that is reflected by the earth's surface, thus being an important variable that controls climate and energy processes on Earth. Surface albedo is directly related to the characteristics of the Earth's surface materials, making it a useful parameter to evaluate the effects of original soil cover replacement due to human occupation. This study evaluated the changes in the surface albedo values due to the conversion of vegetation to other land uses and to analyze the applicability of the use of albedo in the spatial delimitation of land-use classes in the transitional region between the Cerrado and Amazon biomes. Surface albedo measurements were obtained from processing of Landsat Thematic Mapper data in the Geographic Information System (GIS), and land-use information were collected using Google Earth high-resolution images. The results show that human activities such as the cultivation of crops and burning have contributed substantially to variations in the surface albedo, and that albedo estimates from Landsat imagery have the potential to help in the recognition and delimitation of features of land use and cover.Keywords: Landsat 5, reflectance, remote sensing.Albedo de superfície em diferentes classes de uso e cobertura do solo em região de floresta amazônica RESUMO Albedo é a porção de energia solar refletida pela superfície terrestre, sendo assim, uma importante variável que controla os processos climáticos e energéticos sobre a Terra. Albedo da superfície está diretamente relacionado com as características dos materiais da superfície da Terra, tornando-se um parâmetro útil para avaliar os efeitos da substituição de cobertura do solo original devido à ocupação humana. Este estudo objetivou avaliar as alterações nos valores de albedo da superfície em função da conversão da vegetação em outras formas de uso do solo, e analisar a aplicabilidade do uso do albedo na delimitação espacial de classes de uso do solo em região de transição entre os biomas Cerrado e Amazônia. As medidas de albedo da superfície foram obtidas a partir de processamento de dados Landsat Thematic Mapper em sistema SIG e as informações de uso do solo foram obtidas usando imagem de alta resolução do Google Earth.Rev. Ambient. Água vol. 13 n. 2, e2120 -Taubaté 2018 2 Thiago de Oliveira Faria et al.Os resultados demonstram que ações antrópicas sobre a superfície, como desenvolvimento de lavouras e queimadas contribuem substancialmente para as mudanças no albedo de superfície, e que as estimativas de albedo a partir de imagens Landsat apresentam potencial para auxiliar na identificação e delimitação de feições de uso e cobertura do solo.Palavras-chave: Landsat 5, reflectância, sensoriamento remoto.

Monitoring Effects of Land Cover Change on Biophysical Drivers in Rangelands Using Albedo

“…[75] observed that class names used in land cover classification systems are often descriptive without providing detail on the criteria used to define these classes. Water bodies and croplands fall within the literature ranges, while forest/plantation lies within 0.01 of published values for this land cover class, although lower than reported by [36].…”

“…Additionally, the link between modelled landscape change, surface albedo and changes in catchment water and carbon fluxes have not been investigated. Recently, surface albedo was extracted from satellite data per land cover class for calibration of land surface models (LSM) in climate modelling [34,35], while other authors have investigated the potential of albedo in land cover [36] and land cover change analyses [17]. The aim of this paper is to quantify trends and relationships between land cover change, surface albedo, NPP and ET to characterise catchment water and carbon fluxes and postulate consequences on ecosystem services provided by grasslands.…”

“…Landscape changes in the study area were grouped into three land change categories [46,47]. Table 1 shows the land cover class transitions identified by trajectory labels with expected albedo change direction for each class transition, based on literature values [36,48,49] for similar land cover classes, provided in brackets: (↑) to signify increase, (↓) decrease or (-) no change. The land change category is also specified as abrupt (highlighted in light grey), seasonal (dark grey) or gradual ecological change (no background).…”

Reframing tropical savannization: linking changes in canopy structure to energy balance alterations that impact climate

“…Investigations of the impact of forest structure gradients and change on albedo typically contrast forest with highly altered vegetation types canopies. For example, higher albedo is typically found in pasture, crops, and cleared lands, relative to forest, at least after initial post‐fire increases in absorptive charred materials subside (de Oliveira and Moraes 2013, de Oliveira et al 2016, 2019, Faria et al 2018). The albedo of regenerating secondary forest appears to converge toward mature forest values (low values, i.e., ~0.1); however, seasonal differences in albedo and net radiation appear linked to structure in these forests (de Oliveira and Moraes 2013, de Oliveira et al 2016, 2019).…”

Evaluation of methods for estimating atmospheric emissivity in Mato-Grossense Cerrado

“…In the last decades, the anthropic activities in the Cerrado have been causing strong changes in this biome, in particular, in its conversion to pastures and the production of soybean and sugarcane (Klink and Moreira, 2002;Rodrigues et al, 2014), besides the high rates of deforestation that are causing a mosaic of natural forests and arable land (Biudes et al, 2015). That mosaic implies land cover changes, provoking changes in the distribution of solar energy that is available to the environment (Novais et al, 2015;Faria et al, 2018), which affects directly the biophysical process linked to regional energy balance (Rodrigues et al, 2016).…”