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Registro Completo |
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Biblioteca(s): |
Embrapa Solos. |
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Data corrente: |
08/09/2020 |
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Data da última atualização: |
08/09/2020 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
RODRIGUES, H. M.; VASQUES, G. de M.; OLIVEIRA, R. P. de; TAVARES, S. R. de L.; CEDDIA, M. B.; HERNANI, L. C. |
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Afiliação: |
HUGO MACHADO RODRIGUES, UFRRJ; GUSTAVO DE MATTOS VASQUES, CNPS; RONALDO PEREIRA DE OLIVEIRA, CNPS; SILVIO ROBERTO DE LUCENA TAVARES, CNPS; MARCOS BACIS CEDDIA, UFRRJ; LUIS CARLOS HERNANI, CNPS. |
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Título: |
Finding suitable transect spacing and sampling designs for accurate soil ECa mapping from EM38-MK2. |
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Ano de publicação: |
2020 |
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Fonte/Imprenta: |
Soil Systems, v. 4, n. 3, 56, 2020. |
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DOI: |
https://doi.org/10.3390/soilsystems4030056 |
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Idioma: |
Inglês |
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Conteúdo: |
Finding an ideal sampling design is a crucial stage in detailed soil mapping to assure reasonable accuracy of resulting soil property maps. This study aimed to evaluate the influence of sampling designs and sample sizes on the quality of soil apparent electrical conductivity (ECa) maps from an electromagnetic sensor survey. Twenty-six (26) parallel transects were gathered in a 72-ha plot in Southeastern Brazil. Soil ECa measurements using an on-the-go electromagnetic induction sensor were taken every second using sensor vertical orientation. Two approaches were used to reduce the sample size and simulate kriging interpolations of soil ECa. Firstly, the number of transect lines was reduced by increasing the distance between them; thus, 26 transects with 40 m spacing; 13 with 80 m; 7 with 150 m; and 4 with 300 m. Secondly, random point selection and Douglas-Peucker algorithms were used to derive four reduced datasets by removing 25, 50, 75, and 95% of the points from the ECa survey dataset. Soil ECa was interpolated at 5 m output spatial resolution using ordinary kriging and the four datasets from each simulation (a total of twelve datasets). Map uncertainty was assessed by root mean square error and mean error metrics from 400 random samples previously selected for external map validation. Maps were evaluated on their uncertainty and spatial structure of variation. The transect elimination approach showed that maps produced with transect spacing up to 150 m could preserve the spatial structure of ECa variations. Douglas-Peucker results showed lower nugget values than random point simulations for all selected sample densities, except for a 95% point reduction. The soil ECa maps derived from the 75% reduced dataset (by random sampling or Douglas-Peucker) or from 13 transect lines (80 m spacing) showed reasonable accuracy (RMSE of validation circa 0.7) relative to the map interpolated from all survey points (RMSE of 0.5), suggesting that transect spacing of 80 m and reading intervals greater than one second can be used for improving the efficiency of on-the-go soil ECa surveys. MenosFinding an ideal sampling design is a crucial stage in detailed soil mapping to assure reasonable accuracy of resulting soil property maps. This study aimed to evaluate the influence of sampling designs and sample sizes on the quality of soil apparent electrical conductivity (ECa) maps from an electromagnetic sensor survey. Twenty-six (26) parallel transects were gathered in a 72-ha plot in Southeastern Brazil. Soil ECa measurements using an on-the-go electromagnetic induction sensor were taken every second using sensor vertical orientation. Two approaches were used to reduce the sample size and simulate kriging interpolations of soil ECa. Firstly, the number of transect lines was reduced by increasing the distance between them; thus, 26 transects with 40 m spacing; 13 with 80 m; 7 with 150 m; and 4 with 300 m. Secondly, random point selection and Douglas-Peucker algorithms were used to derive four reduced datasets by removing 25, 50, 75, and 95% of the points from the ECa survey dataset. Soil ECa was interpolated at 5 m output spatial resolution using ordinary kriging and the four datasets from each simulation (a total of twelve datasets). Map uncertainty was assessed by root mean square error and mean error metrics from 400 random samples previously selected for external map validation. Maps were evaluated on their uncertainty and spatial structure of variation. The transect elimination approach showed that maps produced with transect spacing up to 150 m could preserve the... Mostrar Tudo |
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Palavras-Chave: |
Geoestatística; Incerteza; Krigagem; Sensoriamento proximal do solo. |
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Thesagro: |
Sensoriamento Remoto. |
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Thesaurus Nal: |
Geostatistics; Kriging; Remote sensing; Uncertainty. |
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Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/215820/1/Finding-suitable-transect-spacing-and-sampling-designs-for-accurate-soil-2020.pdf
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Marc: |
LEADER 03005naa a2200301 a 4500
001 2124782
005 2020-09-08
008 2020 bl uuuu u00u1 u #d
024 7 $ahttps://doi.org/10.3390/soilsystems4030056$2DOI
100 1 $aRODRIGUES, H. M.
245 $aFinding suitable transect spacing and sampling designs for accurate soil ECa mapping from EM38-MK2.$h[electronic resource]
260 $c2020
520 $aFinding an ideal sampling design is a crucial stage in detailed soil mapping to assure reasonable accuracy of resulting soil property maps. This study aimed to evaluate the influence of sampling designs and sample sizes on the quality of soil apparent electrical conductivity (ECa) maps from an electromagnetic sensor survey. Twenty-six (26) parallel transects were gathered in a 72-ha plot in Southeastern Brazil. Soil ECa measurements using an on-the-go electromagnetic induction sensor were taken every second using sensor vertical orientation. Two approaches were used to reduce the sample size and simulate kriging interpolations of soil ECa. Firstly, the number of transect lines was reduced by increasing the distance between them; thus, 26 transects with 40 m spacing; 13 with 80 m; 7 with 150 m; and 4 with 300 m. Secondly, random point selection and Douglas-Peucker algorithms were used to derive four reduced datasets by removing 25, 50, 75, and 95% of the points from the ECa survey dataset. Soil ECa was interpolated at 5 m output spatial resolution using ordinary kriging and the four datasets from each simulation (a total of twelve datasets). Map uncertainty was assessed by root mean square error and mean error metrics from 400 random samples previously selected for external map validation. Maps were evaluated on their uncertainty and spatial structure of variation. The transect elimination approach showed that maps produced with transect spacing up to 150 m could preserve the spatial structure of ECa variations. Douglas-Peucker results showed lower nugget values than random point simulations for all selected sample densities, except for a 95% point reduction. The soil ECa maps derived from the 75% reduced dataset (by random sampling or Douglas-Peucker) or from 13 transect lines (80 m spacing) showed reasonable accuracy (RMSE of validation circa 0.7) relative to the map interpolated from all survey points (RMSE of 0.5), suggesting that transect spacing of 80 m and reading intervals greater than one second can be used for improving the efficiency of on-the-go soil ECa surveys.
650 $aGeostatistics
650 $aKriging
650 $aRemote sensing
650 $aUncertainty
650 $aSensoriamento Remoto
653 $aGeoestatística
653 $aIncerteza
653 $aKrigagem
653 $aSensoriamento proximal do solo
700 1 $aVASQUES, G. de M.
700 1 $aOLIVEIRA, R. P. de
700 1 $aTAVARES, S. R. de L.
700 1 $aCEDDIA, M. B.
700 1 $aHERNANI, L. C.
773 $tSoil Systems$gv. 4, n. 3, 56, 2020.
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Registro original: |
Embrapa Solos (CNPS) |
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 | Acesso ao texto completo restrito à biblioteca da Embrapa Gado de Corte. Para informações adicionais entre em contato com cnpgc.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Gado de Corte. |
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Data corrente: |
03/08/2011 |
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Data da última atualização: |
16/04/2012 |
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Tipo da produção científica: |
Artigo de Divulgação na Mídia |
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Autoria: |
VALLE, C. B. do. |
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Afiliação: |
CACILDA BORGES DO VALLE, CNPGC. |
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Título: |
BRS Tupi é alternativa para solos pobres. |
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Ano de publicação: |
2011 |
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Fonte/Imprenta: |
DBO o portal de negócios da pecuária, 2011. Disponível em: . Acesso em: 10 maio. 2011. |
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Idioma: |
Português |
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Palavras-Chave: |
BRS Tupi; Forrageira. |
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Thesagro: |
Pastagem. |
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Categoria do assunto: |
K Ciência Florestal e Produtos de Origem Vegetal |
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Marc: |
LEADER 00442nam a2200133 a 4500
001 1897265
005 2012-04-16
008 2011 bl uuuu u00u1 u #d
100 1 $aVALLE, C. B. do
245 $aBRS Tupi é alternativa para solos pobres.
260 $aDBO o portal de negócios da pecuária, 2011. Disponível em: <http://www.portaldbo.com.br/portal>. Acesso em: 10 maio. 2011.$c2011
650 $aPastagem
653 $aBRS Tupi
653 $aForrageira
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