GEOSTATISTICAL ANALYSIS OF TOPSOIL FREE IRON OXIDES CONTENT USING COKRIGING | ||
| Journal of Soil Sciences and Agricultural Engineering | ||
| Article 3, Volume 30, Issue 4, April 2005, Pages 2275-2291 PDF (1.14 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jssae.2005.227506 | ||
| Author | ||
| A. M. Moustafa | ||
| Soil and Water Science DepartmentI Faculty of Agriculture (El-Shatby), Alexandria University, Egypt | ||
| Abstract | ||
| Geostatistics provides descriptive tools to characterize the spatial distribution of soil attributes. Kn'ging techniques rely on the spatial dependence between observations to predict attribute values at un-sampled locations. Cokriging on the other hand. utilizes the spatial correlation between two variables to map the primary one. which is under-sampled. using information content of the secondary variable. The present study aimed at applying cokn'ging technique to map topsoil free iron oxides content (Fed) (primary variable) measured in 32 samples. using the information content of topsoil clay contnel (secondary variable) measured in 54 samples. Topsoil Fed ranged between 2.10 and 4.80%. whereas topsoil clay content varied from 24.0 to 69.0%. The correlation coefficient, r. between the two variables is 0.93. which satisfies the most important criteria for carrying out cokriging. The fitted semivariograms for both variables are Gaussian, and the cross-semivariogram between the two variables is also Gaussian. The cokriged spatial distribution of topsoil Fed was mapped and compared to kriged Fed. The cokriging results were cross- validated and the standard error of estimation was matched to that of kriging. The study showed the superiority of cokriging upon kriging as a spatial mapping method. especially if the primary variable is under-sampled. | ||
| Keywords | ||
| Terra Rossa. Geostatistical analysis. Cokriging; Kriging; Clay contnet‘ Free iron oxides; Cross-semivariograrn. Semivariogram | ||
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