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dc.contributor.authorSouza, Vanessa de Arrudapt_BR
dc.contributor.authorRoberti, Débora Reginapt_BR
dc.contributor.authorRuhoff, Anderson Luispt_BR
dc.contributor.authorZimmer, Tamirespt_BR
dc.contributor.authorAdamatti, Daniela Santinipt_BR
dc.contributor.authorGonçalves, Luis Gustavo Gonçalves dept_BR
dc.contributor.authorDiaz, Marcelo Bortoluzzipt_BR
dc.contributor.authorAlves, Rita de Cássia Marquespt_BR
dc.contributor.authorMoraes, Osvaldo Luiz Leal dept_BR
dc.date.accessioned2019-12-20T04:03:05Zpt_BR
dc.date.issued2019pt_BR
dc.identifier.issn2073-4441pt_BR
dc.identifier.urihttp://hdl.handle.net/10183/203587pt_BR
dc.description.abstractEvapotranspiration (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.en
dc.format.mimetypeapplication/pdfpt_BR
dc.language.isoengpt_BR
dc.relation.ispartofWater. Basel : MDPI. Vol. 11, n. 9 (Sept. 2019), 1911, 23 p.pt_BR
dc.rightsOpen Accessen
dc.subjectEvapotranspirationen
dc.subjectEvapotranspiraçãopt_BR
dc.subjectSensoriamento remotopt_BR
dc.subjectFlooded rice paddyen
dc.subjectCultura irrigadapt_BR
dc.subjectIrrigationen
dc.subjectRemote sensingen
dc.subjectMODISen
dc.subjectMOD16 algorithmen
dc.subjectEddy covarianceen
dc.subjectMeteorological measurementsen
dc.titleEvaluation of MOD16 algorithm over irrigated rice paddy using flux tower measurements in Southern Brazilpt_BR
dc.typeArtigo de periódicopt_BR
dc.identifier.nrb001103186pt_BR
dc.type.originEstrangeiropt_BR


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