Change of Support (Volume)

The elementary variogram $2/gamma(/boma{h})$, estimated from experimental data, is defined on the support of these data, e.g., core samples of given cross-section and length. By means of the formula for the estimation variance, the variogram $2/gamma_V(/boma{h})$ defined on any other support $V$ can be deduced from the variogram $2/gamma(/boma{h})$, e.g., $V$ may be the support of the mining block. In fact,

appears as the variance of estimation of the mean grade of the block $V$ centered on point $/boma{x}$ by the mean grade of the block $V$ centered on the point $/boma{x}+/boma{h}$. This formalism for the change of support has great practical applications. Since future mining will be carried out on the basis of blocks and not drill cores, it is of great benefit to be able to evaluate the spatial variability of the mean grades of these blocks by means of the variogram $2/gamma_V(/boma{h})$ defined on the block support.