in earth sciences (soil science). Variance of Kriging is often proposed as a statistical technique
with superior mathematical properties such as a minimum error variance. However, the
robustness and simplicity of IDW motivate its continued use. This research aims to compare the
two interpolation techniques (Inverse Distance Weighting and Kriging), as well as to evaluate
the effect of sampling density on mapping accuracy of soil properties with diverse spatial
structure and diverse variability in a quest to improve interpolation quality for soil chemical
property mapping.
The comparison of these interpolation methods is achieved using the total error of crossvalidation
and validation statistics. Mean Prediction Error and Root Mean Square Error are
calculated and combined to determine which interpolator produced the lowest total error. The
interpolator that produced the lowest total error portrays the most accurate soil property
predictions of the study area.
The finding of this study strongly suggests that the accuracy achieved in mapping soil properties
strongly depends on the spatial structure of the data. This was clearly visible, in that, when the
subset training data set was decreased, the total error increased. The results also confirmed
that systematic sampling pattern provides more accurate results than random sampling pattern.
The overall results obtained from the comparison of the two applied interpolation methods
indicated that Kriging was the most suitable method for prediction and mapping the spatial
distribution of soil chemical properties in this study area.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-08202014-150143 |
| Date | 20 August 2014 |
| Creators | Mtshawu, Babalwa |
| Contributors | Dr CH Barker |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-08202014-150143/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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