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Registro Completo |
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Biblioteca(s): |
Embrapa Agricultura Digital. |
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Data corrente: |
28/04/2009 |
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Data da última atualização: |
01/12/2010 |
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Autoria: |
GARCIA, B. I. L.; SENTELHAS, P. C.; TAPIA, L.; SPAROVEK, G. |
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Afiliação: |
BEATRIZ IBET LOZADA GARCIA, INIA, Venezuela; PAULO CESAR SENTELHAS, ESALQ/USP; LUCIANO TAPIA, CIAGRI/USP; GERD SPAROVEK, ESALQ/USP. |
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Título: |
Filling in missing rainfall data in the Andes region of Venezuela, based on a cluster analysis approach. |
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Ano de publicação: |
2006 |
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Fonte/Imprenta: |
Revista Brasileira de Agrometeorologia, Piracicaba, v. 14, n. 2, p. 225-233, 2006. |
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Idioma: |
Inglês |
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Conteúdo: |
Several agrometeorological studies require daily rainfall, mainly those wich have as objective to model or simulate water budget, crop development and yield, and occurrence of crop pests and diseases. However, the presence of missing data is a problem that normally occurs, which limits these studies. The origin of this problem varies, but they are more related to improperly devices functioning or lack of technical officers to make observations. Such problems are common in the different institutions which control weather-stations networks in Venezuela. Simple and feasible alternatives to improve the quality of rainfall database are required. We established the hypothesis that daily rainfall data from a weather station can be used to fill in missing data from another surrounding weather station. Data used to test our hypothesis were obtained from 106 weather stations in the Andes region, Venezuela, considering a period of 31 years (1967-1997). The original rainfall database presented 17.3% of missing data (207,534 days). Using a cluster analysis (Ward's method, with Euclidean distance), the proposed method, named as Closest Station, reduced the percentage of missing data to 2.5% (29,495 days). The performance of our proposed method was evaluated by mean absolute error (MAE), which ranged from 1.7 to 4.0 mm day-1, and by Willmott agreement index (d), which was 0.57 for daily basis and 0.83 for monthly basis. The contingency analysis showed that our proposed method overestimated rainfall events for daily data, which resulted in a small fraction of correct estimates (FC = 0.48) and a larger false alarm ratio (FAR = 0.53), limiting their use. For the other time scales, from 7 to 30 days, FC was greater than 0.88 and FAR smaller than 0.07, which allow the use of this technique for several purposes in agrometeorological studies. MenosSeveral agrometeorological studies require daily rainfall, mainly those wich have as objective to model or simulate water budget, crop development and yield, and occurrence of crop pests and diseases. However, the presence of missing data is a problem that normally occurs, which limits these studies. The origin of this problem varies, but they are more related to improperly devices functioning or lack of technical officers to make observations. Such problems are common in the different institutions which control weather-stations networks in Venezuela. Simple and feasible alternatives to improve the quality of rainfall database are required. We established the hypothesis that daily rainfall data from a weather station can be used to fill in missing data from another surrounding weather station. Data used to test our hypothesis were obtained from 106 weather stations in the Andes region, Venezuela, considering a period of 31 years (1967-1997). The original rainfall database presented 17.3% of missing data (207,534 days). Using a cluster analysis (Ward's method, with Euclidean distance), the proposed method, named as Closest Station, reduced the percentage of missing data to 2.5% (29,495 days). The performance of our proposed method was evaluated by mean absolute error (MAE), which ranged from 1.7 to 4.0 mm day-1, and by Willmott agreement index (d), which was 0.57 for daily basis and 0.83 for monthly basis. The contingency analysis showed that our proposed method overestimate... Mostrar Tudo |
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Palavras-Chave: |
Método Estação mais próxima; Precipitação; Séries históricas. |
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Thesagro: |
Chuva; Climatologia. |
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Categoria do assunto: |
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Marc: |
LEADER 02520naa a2200217 a 4500
001 1032142
005 2010-12-01
008 2006 bl uuuu u00u1 u #d
100 1 $aGARCIA, B. I. L.
245 $aFilling in missing rainfall data in the Andes region of Venezuela, based on a cluster analysis approach.
260 $c2006
520 $aSeveral agrometeorological studies require daily rainfall, mainly those wich have as objective to model or simulate water budget, crop development and yield, and occurrence of crop pests and diseases. However, the presence of missing data is a problem that normally occurs, which limits these studies. The origin of this problem varies, but they are more related to improperly devices functioning or lack of technical officers to make observations. Such problems are common in the different institutions which control weather-stations networks in Venezuela. Simple and feasible alternatives to improve the quality of rainfall database are required. We established the hypothesis that daily rainfall data from a weather station can be used to fill in missing data from another surrounding weather station. Data used to test our hypothesis were obtained from 106 weather stations in the Andes region, Venezuela, considering a period of 31 years (1967-1997). The original rainfall database presented 17.3% of missing data (207,534 days). Using a cluster analysis (Ward's method, with Euclidean distance), the proposed method, named as Closest Station, reduced the percentage of missing data to 2.5% (29,495 days). The performance of our proposed method was evaluated by mean absolute error (MAE), which ranged from 1.7 to 4.0 mm day-1, and by Willmott agreement index (d), which was 0.57 for daily basis and 0.83 for monthly basis. The contingency analysis showed that our proposed method overestimated rainfall events for daily data, which resulted in a small fraction of correct estimates (FC = 0.48) and a larger false alarm ratio (FAR = 0.53), limiting their use. For the other time scales, from 7 to 30 days, FC was greater than 0.88 and FAR smaller than 0.07, which allow the use of this technique for several purposes in agrometeorological studies.
650 $aChuva
650 $aClimatologia
653 $aMétodo Estação mais próxima
653 $aPrecipitação
653 $aSéries históricas
700 1 $aSENTELHAS, P. C.
700 1 $aTAPIA, L.
700 1 $aSPAROVEK, G.
773 $tRevista Brasileira de Agrometeorologia, Piracicaba$gv. 14, n. 2, p. 225-233, 2006.
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Registro original: |
Embrapa Agricultura Digital (CNPTIA) |
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| Registros recuperados : 11 | |
| 2. |  | FIORIO, P. R.; DEMATTÊ, J. A. M.; SPAROVEK, G. Cronologia e impacto ambiental do uso da terra na Microbacia Hidrográfica do Ceveiro, em Piracicaba, SP. Pesquisa Agropecuária Brasileira, Brasília, DF, v. 35, n. 4, p. 671-679, abr. 2000. Título em inglês: Cronology and environmental impact of land use on Ceveiro Microbasin in Piracicaba region, Brazil.| Biblioteca(s): Embrapa Unidades Centrais. |
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| 4. | | FOCHT, D.; SPAROVEK, G.; SILVA, E. F. da; RANIERI, S. B. L.; WEILL, M. A. M. Influência do avaliador no resultado da classificação de terras em capacidade de uso. In: CONGRESSO BRASILEIRO DE CIÊNCIA DO SOLO, 27., 1999, Brasília, DF. Resumos [...]. Planaltina, DF: Embrapa Cerrados, 1999. 1 CD-ROM.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Solos. |
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| 6. | | BENEDETTI, M. M.; SPAROVEK, G.; COOPER, M.; CURI, N.; CARVALHO FILHO, A. de. Representatividade e potencial de utilização de um banco de dados de solos do Brasil. Revista Brasileira de Ciência do Solo, Viçosa, MG, v. 32, n. 6, p. 2591-2600, nov/dez. 2008.| Tipo: Nota Técnica/Nota Científica |
| Biblioteca(s): Embrapa Solos. |
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| 7. | | TORRES, M. L. G.; PARRA, J. R. P.; NAVA, D. E.; ASUNCAO, A. L. C.; FREITAS, F. M.; SPAROVEK, G. Determinação do número de gerações de Diaphorina citri (Hemiptera: Psyllidae) e de seu parasitóide Tamarixia radiata (Hymenoptera: Eulophidae) no estado de São Paulo, baseando-se em um sistema de informações geográficas (SIG). In: CONGRESSO BRASILEIRO DE ENTOMOLOGIA, 22., 2008, Uberlândia. Ciência, tecnologia e inovação: anais... Uberlândia: Sociedade Entomológica do Brasil, 2008. 1 CD-ROM.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Clima Temperado. |
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| 8. | | FERREIRA, J.; PARDINI, R.; METZGER, J. P.; FONSECA, C. R.; POMPEU, P. S.; SPAROVEK, G.; LOUZADA, J. Towards environmentally sustainable agriculture in Brazil: challenges and opportunities for applied ecological research. Journal of Applied Ecology, v. 49, n. 3, p. 535-541, Jun. 2012.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 1 |
| Biblioteca(s): Embrapa Amazônia Oriental. |
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| 9. | | SPAROVEK, G.; BARETTO, A. G. de O. P.; MAULE, R. F.; MARTINS, S. P.; SMORIGO, J. N. Increase in social and environmental standards to Brazilian sugarcane expansion pathways. In: FALEIRO, F. G.; FARIAS NETO, A. L. de (Ed.). Savanas: desafios e estratégias para o equilíbrio entre sociedade, agronegócio e recursos naturais. Planaltina, DF: Embrapa Cerrados, 2008. cap. 22, p. 745-761.| Biblioteca(s): Embrapa Cerrados. |
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| 10. | | CERRI, C. E. P.; TORNQUIST, C. G.; BERNOUX, M.; COOPER, M.; SPAROVEK, G.; MENDONÇA-SANTOS, M. de L.; CERRI, C. C. Integrated digital, spatial, and attribute databases for soils in Brazil. In: HUANG, P. M.; LI, Y.; SUMNER, M. E. (ed.). Handbook of soil sciences: resource management and environmental impacts. 2nd ed. Boca Raton: CRC Press, 2011. cap. 29.| Tipo: Capítulo em Livro Técnico-Científico |
| Biblioteca(s): Embrapa Solos. |
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| 11. | | JOLY, C. A.; PADGURSCHI, M. C. G.; PIRES, A. P. F.; AGOSTINHO, A. A.; MARQUES, A. C.; AMARAL, A. G.; CERVONE, C. O. F. de O.; ADAMS, C.; BACCARO, F. B.; SPAROVEK, G.; OVERBECK, G. E.; ESPINDOLA, G. M. de; VIEIRA, I. C. G.; METZGER, J. P.; SABINO, J.; FARINACI, J. S.; QUEIROZ, L. P. de; GOMES, L. C.; CUNHA, M. M. C. da; PIEDADE, M. T. F.; BUSTAMANTE, M. M. da C.; MAY, P.; FEARNSIDE, P.; PRADO, R. B.; LOYOLA, R. D. Apresentando o diagnóstico brasileiro de biodiversidade e serviços ecossistêmicos. In: JOLY, C. A.; SCARANO, F. R.; SEIXAS, C. S.; METZGER, J. P.; OMETTO, J. P.; BUSTAMANTE, M. M. C.; PADGURSCHI, M. C. G.; PIRES, A. P. F.; CASTRO, P. F. D.; GADDA, T.; TOLEDO, P. (Ed.). 1° Diagnóstico brasileiro de biodiversidade e serviços ecossistêmicos. São Carlos, SP: Editora Cubo, 2019. cap. 1, p. 6-33.| Tipo: Capítulo em Livro Técnico-Científico |
| Biblioteca(s): Embrapa Solos. |
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| Registros recuperados : 11 | |
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| Nenhum registro encontrado para a expressão de busca informada. |
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