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    <subfield code="a">Lundgren, Wellington Jorge Cavalcanti</subfield>
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    <subfield code="a">Silva, Jos&#xE9; Ant&#xF4;nio Aleixo da</subfield>
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    <subfield code="a">Ferreira, Rinaldo Luiz Caraciolo </subfield>
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    <subfield code="a">A Precis&#xE3;o da Estimativa do Erro da Krigagem pela Valida&#xE7;&#xE3;o Cruzada</subfield>
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    <subfield code="a">Publica&#xE7;&#xE3;o on-line; 17 ref.; 2 tables; 7 illus.; Summaries (En, Pt)</subfield>
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RESUMO

A Valida&#xE7;&#xE3;o Cruzada (VC) &#xE9; utilizada para verifica&#xE7;&#xE3;o de erros de estimativas em krigagem.
Para quantificar o erro cometido pela VC, um plantio de 1875 &#xE1;rvores de eucaliptos foi cubado
rigorosamente. Um mapa do volume/&#xE1;rvore foi constru&#xED;do por krigagem e gerou 8736 pontos.
Amostras de tamanhos 100, 150, 200, 250, 300 e 350 foram retiradas dos 8736 pontos por
amostragem sistem&#xE1;tica e aleat&#xF3;ria e mapas foram constru&#xED;dos por krigagem. Uma reta foi
ajustada ao gr&#xE1;fico Estimados x Observados. O R2, o intercepto e o coeficiente angular foram
os par&#xE2;metros de erros. A VC n&#xE3;o forneceu resultados confi&#xE1;veis para o R2 na amostragem
sistem&#xE1;tica com 100, 150, 200 e 250 amostras e confi&#xE1;veis para o R2 em todas as amostragens
aleat&#xF3;rias. A amostragem sistem&#xE1;tica apresentou bons resultados verdadeiros, o R2&gt; 0,70 com
200 amostras, e a amostragem aleat&#xF3;ria s&#xF3; apresentou R2&gt; 0,70 com 250 amostras.

Palavras-chaves: eucaliptos, semi&#xE1;rido, geoestat&#xED;stica, interpola&#xE7;&#xE3;o, volume de madeira.





Accuracy of the Kriging Error Estimate Through Cross Validation

ABSTRACT

Cross-validation (CV) is used for error checking in kriging estimates. To quantify the error of a
CV, 1875 eucalyptus trees were rigorously planted. A volume/tree map was constructed by kriging,
generating 8736 points. Samples with different sizes (100, 150, 200, 250, 300 and 350) were taken
from the 8736 points through systematic and random sampling and volume maps were constructed
by kriging. A straight line was fitted to Estimated x Observed graph. The R2, the intercept and
the slope were the errors parameters. The CV did not provide reliable results for the R2 in the
systematic sampling with 100, 150, 200 and 250 samples, but it was reliable for the R2 in all
randomized trials. The systematic sampling had good real results, R2&gt; 0.70 with 200 samples,
while random sampling showed R2 &gt; 0.70 only with 250 samples. 

Keywords: eucalyptus, semiarid, geostatistics, interpolation, volume of wood.</subfield>
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    <subfield code="a">EUCALIPTO</subfield>
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    <subfield code="a">ESTAT&#xCD;STICA</subfield>
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    <subfield code="a">VOLUME</subfield>
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    <subfield code="a">MADEIRA</subfield>
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    <subfield code="0">2929</subfield>
    <subfield code="9">347945</subfield>
    <subfield code="d">Rio de Janeiro-RJ Instituto de Florestas - UFRRJ 1994</subfield>
    <subfield code="o">2025-0444</subfield>
    <subfield code="t">Floresta e Ambiente (Brazil)</subfield>
    <subfield code="x">1415-0980  /  ISSN 2179-8087 0nline</subfield>
    <subfield code="g">v. 24 p. 1-12; (2017)</subfield>
    <subfield code="w">BR2026000281</subfield>
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    <subfield code="u">https://www.scielo.br/j/floram/a/G8jJ6VsbhJQ8qLtLhNgYZMk/?format=pdf&amp;lang=pt</subfield>
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