Scaling of semivariograms and the kriging estimation of field-measured properties
Two methods were evaluated for scaling a set of semivariograms into a unified function for kriging estimation of field-measured properties. Scaling is performed using sample variances and sills of individual semivariograms as scale factors. Theoretical developments show that kriging weights are inde...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Ciência do Solo
1997-12-01
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| Series: | Revista Brasileira de Ciência do Solo |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06831997000400001&lng=en&tlng=en |
| _version_ | 1818722007428104192 |
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| author | S. R. Vieira P. M. Tillotson J. W. Biggar D. R. Nielsen |
| author_facet | S. R. Vieira P. M. Tillotson J. W. Biggar D. R. Nielsen |
| author_sort | S. R. Vieira |
| collection | DOAJ |
| description | Two methods were evaluated for scaling a set of semivariograms into a unified function for kriging estimation of field-measured properties. Scaling is performed using sample variances and sills of individual semivariograms as scale factors. Theoretical developments show that kriging weights are independent of the scaling factor which appears simply as a constant multiplying both sides of the kriging equations. The scaling techniques were applied to four sets of semivariograms representing spatial scales of 30 x 30 m to 600 x 900 km. Experimental semivariograms in each set successfully coalesced into a single curve by variances and sills of individual semivariograms. To evaluate the scaling techniques, kriged estimates derived from scaled semivariogram models were compared with those derived from unscaled models. Differences in kriged estimates of the order of 5% were found for the cases in which the scaling technique was not successful in coalescing the individual semivariograms, which also means that the spatial variability of these properties is different. The proposed scaling techniques enhance interpretation of semivariograms when a variety of measurements are made at the same location. They also reduce computational times for kriging estimations because kriging weights only need to be calculated for one variable. Weights remain unchanged for all other variables in the data set whose semivariograms are scaled. |
| first_indexed | 2024-12-17T20:47:47Z |
| format | Article |
| id | doaj.art-c5ed1301e8494437a872e7ba930f1aa7 |
| institution | Directory Open Access Journal |
| issn | 1806-9657 |
| language | English |
| last_indexed | 2024-12-17T20:47:47Z |
| publishDate | 1997-12-01 |
| publisher | Sociedade Brasileira de Ciência do Solo |
| record_format | Article |
| series | Revista Brasileira de Ciência do Solo |
| spelling | doaj.art-c5ed1301e8494437a872e7ba930f1aa72022-12-21T21:33:07ZengSociedade Brasileira de Ciência do SoloRevista Brasileira de Ciência do Solo1806-96571997-12-0121452553310.1590/S0100-06831997000400001S0100-06831997000400001Scaling of semivariograms and the kriging estimation of field-measured propertiesS. R. Vieira0P. M. Tillotson1J. W. Biggar2D. R. Nielsen3Insituto AgronômicoUniversity of GeorgiaUniversity of CaliforniaUniversity of CaliforniaTwo methods were evaluated for scaling a set of semivariograms into a unified function for kriging estimation of field-measured properties. Scaling is performed using sample variances and sills of individual semivariograms as scale factors. Theoretical developments show that kriging weights are independent of the scaling factor which appears simply as a constant multiplying both sides of the kriging equations. The scaling techniques were applied to four sets of semivariograms representing spatial scales of 30 x 30 m to 600 x 900 km. Experimental semivariograms in each set successfully coalesced into a single curve by variances and sills of individual semivariograms. To evaluate the scaling techniques, kriged estimates derived from scaled semivariogram models were compared with those derived from unscaled models. Differences in kriged estimates of the order of 5% were found for the cases in which the scaling technique was not successful in coalescing the individual semivariograms, which also means that the spatial variability of these properties is different. The proposed scaling techniques enhance interpretation of semivariograms when a variety of measurements are made at the same location. They also reduce computational times for kriging estimations because kriging weights only need to be calculated for one variable. Weights remain unchanged for all other variables in the data set whose semivariograms are scaled.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06831997000400001&lng=en&tlng=enSemivariogramasescalonamentokrigagemvariabilidade espacial |
| spellingShingle | S. R. Vieira P. M. Tillotson J. W. Biggar D. R. Nielsen Scaling of semivariograms and the kriging estimation of field-measured properties Revista Brasileira de Ciência do Solo Semivariogramas escalonamento krigagem variabilidade espacial |
| title | Scaling of semivariograms and the kriging estimation of field-measured properties |
| title_full | Scaling of semivariograms and the kriging estimation of field-measured properties |
| title_fullStr | Scaling of semivariograms and the kriging estimation of field-measured properties |
| title_full_unstemmed | Scaling of semivariograms and the kriging estimation of field-measured properties |
| title_short | Scaling of semivariograms and the kriging estimation of field-measured properties |
| title_sort | scaling of semivariograms and the kriging estimation of field measured properties |
| topic | Semivariogramas escalonamento krigagem variabilidade espacial |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06831997000400001&lng=en&tlng=en |
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