Assessment of automated evapotranspiration estimates obtained using the GP-SEBAL algorithm for dry forest vegetation (Caatinga) and agricultural areas in the Brazilian semiarid region

Evapotranspiration (ET) is the second largest component of the terrestrial hydrological cycle on a global scale. The estimation of ET at regional scale using satellite imagery and algorithms allow the conversion of instantaneous measures in daily totals which represents a major contribution to the study of energy exchange between the biosphere and atmosphere. One of the most important remote sensing algorithms used to estimate the spatial partitioning of energy is the SEBAL -Surface Energy Balance Algorithm for Land. The time processing of this algorithm can be very high depending on the size of the image. Thus, the objective of this study was to propose a framework of the use of graphic processing units (GPU) to run the SEBAL to increase the performance and reduce the time required to run it. For implementation of SEBAL's framework was used local data collected in a micrometeorological tower installed in an area located in the Northern Pantanal (Brazil) and Landsat 5 -TM image. We used the Model Maker function of the ERDAS 9.2 Software to run SEBAL algorithm, and its implementation in Java, CUDA and OpenCL languages. A daily ET estimated by SEBAL in JAVA, CUDA and OpenCL languages were similar to the value performed by ERDAS software. The daily ET computed by the ERDAS software was 10% lower and the SEBAL computed in JAVA language, CUDA and OpenCL was 9% lower than the ET obtained by the Bowen ratio method. The results showed that CUDA was better due to the Speed Up performance up to 35,000 times.

Section: Resultsmentioning

confidence: 99%

The Surface Energy Balance Algorithm for Land (SEBAL) framework in Graphics Processing Units (GPU) using Cuda and OpenCL

Gomes

Danelichen

Biudes

et al. 2021

“…Desta forma, inúmeros estudos são desenvolvidos com o propósito de esclarecer diferentes mecanismos que amenizem os impactos climáticos de uso e ocupação do solo, Silva et al (2013), Morais et al (2017), Miranda et al (2018) e Lima et al (2021), além disso, o aumento populacional e das mudanças climáticas nos recursos hídricos Galvincio (2021), Galvincio et al, (2021). No entanto, para a realização desses estudos, pesquisadores encontram dificuldades diversas, tais como a coleta de dados e, grandes mudanças na ocupação e utilização do solo (Galvincio, 2019;Galvincio e Naue, 2019).…”

Section: Issn:1984-2295unclassified

Avaliação da evapotranspiração estimada pelo MODIS e do balanço hídrico para a bacia do Pontal-Pernambuco

Brito¹,

Miranda

Morais³

et al. 2021

The semi-arid region of northeastern Brazil has a strong tendency to decrease precipitation with climate change. It is known that the social, economic, and environmental impacts will be very high if this happens. Evapotranspiration and water balance are important variables in public policy decision-making related to rain and water resources, as it allows for greater knowledge of the water supply in each region. Thus, evaluating different estimation methodologies for these variables provides an important contribution to the planning of environmental public policies. Given the above, this study aims to evaluate the evapotranspiration estimated with MODIS and the water balance obtained with the Soil Water Assessment Tools (SWAT) for the Pontal basin, Pernambuco, Brazil, for the year 2016. The results show the great dependence of actual evapotranspiration and runoff on the volume of rainfall in the basin. It was possible to verify that the preserved caatinga areas had the highest evapotranspiration throughout the year. Also noteworthy is the volume of water stored in the soil in these areas. The largest volume drained was present in agriculture and livestock and exposed soil. These results show the impacts of anthropic actions on the natural resources of the Po ntal basin, which can lead to greater complications in the region's land cover and water balance.

“…A necessidade de oferecer respostas para os mais variados problemas ambientais fez dos produtos da série Landsat um dos mais utilizados para o monitoramento e gestão ambiental e diferentes unidades de observação. Atualmente, inúmeros trabalhos foram desenvolvidos, com diferentes abordagens, que vão desde as investigações dos impactos das mudanças no uso e cobertura da terra sobre os recursos hídricos, à questões climáticas e de produtividade agrícola (Silva et al, 2013;Machado et al, 2014;Bezerra et al, (2019);Allam;Bakr;Elbably, 2019;Desta;Fetene, 2020;Murad;Pearse, 2018;Shi et al, 2019;Wang, Q. et al, 2020;Lacerda et al, 2020;Lima et al, 2021;Galvincio e Luz, 2021).…”

Section: Introductionunclassified

Mudanças espaço-temporais no uso e cobertura da terra na bacia hidrográfica do rio Pontal a partir de dados referenciais do Google Earth Pro

Gomes¹,

Araújo²,

Galvíncio

2022

Self Cite

O uso e cobertura da terra compreende as diferentes estruturas modeladas a partir de forças de ordens natural e antropogênica. Esse tem sido um dos atributos mais utilizados para monitoramento e planejamento ambiental. O objetivo do presente estudo foi analisar as mudanças espaço-temporais do uso e cobertura da terra na bacia hidrográfica do rio Pontal, localizada no estado de Pernambuco. Para isso, foram empregadas técnicas de geoprocessamento e sensoriamento remoto utilizando classificação supervisionada em imagens orbitais dos satélites Landsat 5 e 8. Para obtenção de pontos de controle optou-se por utilizar as informações do Google Earth Pro, que possui um banco com imagens de alta resolução espacial e assim possibilita o reconhecimento real da área. Os resultados encontrados indicaram, de modo geral, que a metodologia se mostrou viável no sentido de detectar as classes de uso e cobertura da terra encontradas ao longo da área de estudo. A bacia do Pontal possui hoje menos água disponível no seu balanço hídrico para os diferentes usos e sustentabilidade ambiental devido as mudanças climáticas globais e mudanças no uso e ocupação do solo. As técnicas empregadas para o mapeamento do uso e cobertura da bacia hidrográfica do rio Pontal se mostraram consistentes no sentido de representar a variação espacial e temporal da vegetação na referida unidade. Space-temporal changes in land use and coverage in the Pontal river basin based on reference data from Google Earth Pro A B S T R A C TLand use and land cover are structures modeled after natural and anthropogenic orders. This has been one of the most used attributes for environmental monitoring and planning. The objective of the present study was analyzed as spatio-temporal changes in land use and land cover in the Pontal river basin, located in the state of Pernambuco. For this, geoprocessing and remote sensing techniques were used using supervised classification in images from Landsat 5 and 8 satellites. spatial resolution, thus enabling real recognition of the area. The results found indicate, in general, that one methodology showed no sense of detection as viable use classes and land cover along the study area. The Pontal basin today has water available in its water balance for different environmental uses and environmental sustainability and changes in use and less land occupation. The techniques used for the use mapping and tip coverage mentioned.Keywords: Environmental impact; supervised classification; Remote sensing.