The importance of the Validation of the Block Model Estimation with GEOVIA GEMS: GRAPHICAL VALIDATION.
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When estimating a block model, no matter what interpolation method is chosen, it is essential to validate the obtained results in order to ensure the estimation process quality according to the current industry standards.
By validating the block model, we look for:
- That the estimation be globally unbiased
- Minimize local bias
- Keep the estimation smoothing at a reasonably acceptable level
There are numerous methods to do this and through upcoming blogs we will discuss these three (3):
- Graphical validation.
- Statistical validation.
- Swath Plot validation.
First, we will explain the method of Graphical Validation:
GRAPHICAL VALIDATION OF THE BLOCK MODEL ESTIMATION
Objective:
Evaluate in a global and visual way, the coherence and similarities between the estimation (block model) and the real data (composites).
How to do it?
Perform a visual inspection by plans and vertical sections of the estimated blocks and of the composites.
Care to take into account at the execution:
- Composites need to have the same support as the size of the blocks
- Use the same color code to display blocks and composites
- Perform the analysis only on the best estimated blocks, e.g., those that are candidates to be measured and indicated resources
Expected results:
- That the blocks represent the trend or expected anisotropy of the orebodies.
- Similarity and coherence in grade distribution of the estimated blocks with respect to the composites.
This review is subjective but very useful to detect rough problems of over or underestimation or else errors in the grade anisotropy definition. The figures below highlight this process:
Figure 1: Graphical Validation – Plan View
Figure 2: Graphical Validation – Vertical Section EW
Figure 3: Graphical Validation – Vertical Section NS
