Evaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern Brazil

Detalhes bibliográficos
Autor(a) principal: Souza, Vanessa de Arruda
Data de Publicação: 2019
Outros Autores: Roberti, Débora Regina, Ruhoff, Anderson Luis, Zimmer, Tamires, Adamatti, Daniela Santini, Gonçalves, Luis Gustavo Gonçalves de, Diaz, Marcelo Bortoluzzi, Alves, Rita de Cássia Marques, Moraes, Osvaldo Luiz Leal de
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UFRGS
Texto Completo: http://hdl.handle.net/10183/203587
Resumo: Evapotranspiration (ET) is an important component of the hydrological cycle. Understanding the ET process has become of fundamental importance given the scenario of global change and increasing water use, especially in the agricultural sector. Determining ET over large agricultural areas is a limiting factor due to observational data availability. In this regard, remote sensing data has been used to estimate ET. In this study, we evaluated the Moderate-Resolution Imaging Spectroradiometer (MODIS) land surface ET product estimates (hereafter MOD16 ET - MODIS Global Terrestrial Evapotranspiration Product) over two rice paddy areas in Southern Brazil, through the ET measured using the eddy covariance technique (hereafter EC). The energy balance components were evaluated during fallow and flooded seasons showing latent heat flux dominates in both seasons. The results showed that MOD16 ET underestimated EC measurements. Overall, the RMSE (root mean square error) ranged between 13.40 and 16.35 mm 8-day-1 and percent bias (PBIAS) ranged between -33.7% and -38.7%. We also assessed the ET (measured and estimated) main drivers, with EC yielding higher correlation against observed net radiation (Rn) and global radiation (Rg), followed by air temperature (Temp) and vapor pressure deficit (VPD), whilst MOD16 ET estimates yielded higher correlation against leaf area index (LAI) and fraction of photosynthetically active radiation (fPAR). The MOD16 algorithm was forced with meteorological measurements but the results did not improve as expected, suggesting a low sensitivity to meteorological inputs. Our results indicated when a water layer was present over the soil surface without vegetation (LAI around zero), the largest differences between EC measurements and MOD16 ET were found. In this period, the expected domain of soil evaporation was not observed in MOD16 ET physical processes partition, indicating the algorithm was not able to detect areas with high soil moisture. In general, the MOD16 ET product presented low accuracy when compared against experimental measurements over flooded rice paddy, suggesting more studies are necessary, in order to reduce uncertainties associated to the land cover conditions.
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spelling Souza, Vanessa de ArrudaRoberti, Débora ReginaRuhoff, Anderson LuisZimmer, TamiresAdamatti, Daniela SantiniGonçalves, Luis Gustavo Gonçalves deDiaz, Marcelo BortoluzziAlves, Rita de Cássia MarquesMoraes, Osvaldo Luiz Leal de2019-12-20T04:03:05Z20192073-4441http://hdl.handle.net/10183/203587001103186Evapotranspiration (ET) is an important component of the hydrological cycle. Understanding the ET process has become of fundamental importance given the scenario of global change and increasing water use, especially in the agricultural sector. Determining ET over large agricultural areas is a limiting factor due to observational data availability. In this regard, remote sensing data has been used to estimate ET. In this study, we evaluated the Moderate-Resolution Imaging Spectroradiometer (MODIS) land surface ET product estimates (hereafter MOD16 ET - MODIS Global Terrestrial Evapotranspiration Product) over two rice paddy areas in Southern Brazil, through the ET measured using the eddy covariance technique (hereafter EC). The energy balance components were evaluated during fallow and flooded seasons showing latent heat flux dominates in both seasons. The results showed that MOD16 ET underestimated EC measurements. Overall, the RMSE (root mean square error) ranged between 13.40 and 16.35 mm 8-day-1 and percent bias (PBIAS) ranged between -33.7% and -38.7%. We also assessed the ET (measured and estimated) main drivers, with EC yielding higher correlation against observed net radiation (Rn) and global radiation (Rg), followed by air temperature (Temp) and vapor pressure deficit (VPD), whilst MOD16 ET estimates yielded higher correlation against leaf area index (LAI) and fraction of photosynthetically active radiation (fPAR). The MOD16 algorithm was forced with meteorological measurements but the results did not improve as expected, suggesting a low sensitivity to meteorological inputs. Our results indicated when a water layer was present over the soil surface without vegetation (LAI around zero), the largest differences between EC measurements and MOD16 ET were found. In this period, the expected domain of soil evaporation was not observed in MOD16 ET physical processes partition, indicating the algorithm was not able to detect areas with high soil moisture. In general, the MOD16 ET product presented low accuracy when compared against experimental measurements over flooded rice paddy, suggesting more studies are necessary, in order to reduce uncertainties associated to the land cover conditions.application/pdfengWater. Basel : MDPI. Vol. 11, n. 9 (Sept. 2019), 1911, 23 p.EvapotranspiraçãoSensoriamento remotoCultura irrigadaEvapotranspirationFlooded rice paddyIrrigationRemote sensingMODISMOD16 algorithmEddy covarianceMeteorological measurementsEvaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern BrazilEstrangeiroinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSTEXT001103186.pdf.txt001103186.pdf.txtExtracted Texttext/plain75699http://www.lume.ufrgs.br/bitstream/10183/203587/2/001103186.pdf.txtb19c4ba5c8bd331a71ce7a0c205ad548MD52ORIGINAL001103186.pdfTexto completo (inglês)application/pdf19626485http://www.lume.ufrgs.br/bitstream/10183/203587/1/001103186.pdf9b0cb19b36e468d083ad204e3e761b17MD5110183/2035872019-12-21 05:03:07.003391oai:www.lume.ufrgs.br:10183/203587Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2019-12-21T07:03:07Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false
dc.title.pt_BR.fl_str_mv Evaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern Brazil
title Evaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern Brazil
spellingShingle Evaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern Brazil
Souza, Vanessa de Arruda
Evapotranspiração
Sensoriamento remoto
Cultura irrigada
Evapotranspiration
Flooded rice paddy
Irrigation
Remote sensing
MODIS
MOD16 algorithm
Eddy covariance
Meteorological measurements
title_short Evaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern Brazil
title_full Evaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern Brazil
title_fullStr Evaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern Brazil
title_full_unstemmed Evaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern Brazil
title_sort Evaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern Brazil
author Souza, Vanessa de Arruda
author_facet Souza, Vanessa de Arruda
Roberti, Débora Regina
Ruhoff, Anderson Luis
Zimmer, Tamires
Adamatti, Daniela Santini
Gonçalves, Luis Gustavo Gonçalves de
Diaz, Marcelo Bortoluzzi
Alves, Rita de Cássia Marques
Moraes, Osvaldo Luiz Leal de
author_role author
author2 Roberti, Débora Regina
Ruhoff, Anderson Luis
Zimmer, Tamires
Adamatti, Daniela Santini
Gonçalves, Luis Gustavo Gonçalves de
Diaz, Marcelo Bortoluzzi
Alves, Rita de Cássia Marques
Moraes, Osvaldo Luiz Leal de
author2_role author
author
author
author
author
author
author
author
dc.contributor.author.fl_str_mv Souza, Vanessa de Arruda
Roberti, Débora Regina
Ruhoff, Anderson Luis
Zimmer, Tamires
Adamatti, Daniela Santini
Gonçalves, Luis Gustavo Gonçalves de
Diaz, Marcelo Bortoluzzi
Alves, Rita de Cássia Marques
Moraes, Osvaldo Luiz Leal de
dc.subject.por.fl_str_mv Evapotranspiração
Sensoriamento remoto
Cultura irrigada
topic Evapotranspiração
Sensoriamento remoto
Cultura irrigada
Evapotranspiration
Flooded rice paddy
Irrigation
Remote sensing
MODIS
MOD16 algorithm
Eddy covariance
Meteorological measurements
dc.subject.eng.fl_str_mv Evapotranspiration
Flooded rice paddy
Irrigation
Remote sensing
MODIS
MOD16 algorithm
Eddy covariance
Meteorological measurements
description Evapotranspiration (ET) is an important component of the hydrological cycle. Understanding the ET process has become of fundamental importance given the scenario of global change and increasing water use, especially in the agricultural sector. Determining ET over large agricultural areas is a limiting factor due to observational data availability. In this regard, remote sensing data has been used to estimate ET. In this study, we evaluated the Moderate-Resolution Imaging Spectroradiometer (MODIS) land surface ET product estimates (hereafter MOD16 ET - MODIS Global Terrestrial Evapotranspiration Product) over two rice paddy areas in Southern Brazil, through the ET measured using the eddy covariance technique (hereafter EC). The energy balance components were evaluated during fallow and flooded seasons showing latent heat flux dominates in both seasons. The results showed that MOD16 ET underestimated EC measurements. Overall, the RMSE (root mean square error) ranged between 13.40 and 16.35 mm 8-day-1 and percent bias (PBIAS) ranged between -33.7% and -38.7%. We also assessed the ET (measured and estimated) main drivers, with EC yielding higher correlation against observed net radiation (Rn) and global radiation (Rg), followed by air temperature (Temp) and vapor pressure deficit (VPD), whilst MOD16 ET estimates yielded higher correlation against leaf area index (LAI) and fraction of photosynthetically active radiation (fPAR). The MOD16 algorithm was forced with meteorological measurements but the results did not improve as expected, suggesting a low sensitivity to meteorological inputs. Our results indicated when a water layer was present over the soil surface without vegetation (LAI around zero), the largest differences between EC measurements and MOD16 ET were found. In this period, the expected domain of soil evaporation was not observed in MOD16 ET physical processes partition, indicating the algorithm was not able to detect areas with high soil moisture. In general, the MOD16 ET product presented low accuracy when compared against experimental measurements over flooded rice paddy, suggesting more studies are necessary, in order to reduce uncertainties associated to the land cover conditions.
publishDate 2019
dc.date.accessioned.fl_str_mv 2019-12-20T04:03:05Z
dc.date.issued.fl_str_mv 2019
dc.type.driver.fl_str_mv Estrangeiro
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dc.identifier.uri.fl_str_mv http://hdl.handle.net/10183/203587
dc.identifier.issn.pt_BR.fl_str_mv 2073-4441
dc.identifier.nrb.pt_BR.fl_str_mv 001103186
identifier_str_mv 2073-4441
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url http://hdl.handle.net/10183/203587
dc.language.iso.fl_str_mv eng
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dc.relation.ispartof.pt_BR.fl_str_mv Water. Basel : MDPI. Vol. 11, n. 9 (Sept. 2019), 1911, 23 p.
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