[Effect of exploratory techniques on the geostatistical analysis in a soil of the State Aragua]
1995
Rey, J.C. | Ovalles Viani, F.
Geostatistics requires that stationarity and normality assumptions should be fulfilled; otherwise, some questions arise as to the appropriateness of semivariograms. In order to compare results, phosphorus levels data of a experimental plot located in the Aragua state, were subjected to geostatistical analysis (semivariogram and kriging). The analysis was performed in two ways: original data and modified data by an exploratory analysis based on histograms, transformations and median-based techniques to remove the drift (residuals). Phosphorus residual showed a distribution close to normal and the mean and variance stationarity was fulfilled. Semivariograms were transitive; however, the sill of the original data was greater than the sample variance, as a consequence the non stationarity and drift were present. The sill and sample variance for residuals were similar; there by, median, based techniques removes drift and raised the assumption of stationarity. The diagrams of kriged values for original data and residuals were similar; therefore, kriging method depends on data and its distribution more than on semivariograms.
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