Geostatistical evaluation of reserve for coal mine and comparision to traditional method

The coal mine area covers 540km² a partion in which is studied. The information available comes from 97 holes drilled on about a 250m to 500m grid.One should compute four variograms of coal thickness in 0°, 45°, 90°, 135° direction, but experimental variogram is too dispersed to fit a mathematical model,because the thickness variableis’nt normally distrbuted with outliers. Consequently one should obtain a robust variogram rejecting the outliers. To checke a influence of models on Kriging estimation one calculcd local estimation with three moders and their results are compared with traditional methods of reserve.