INVESTIGATION OF A SUITABLE MODEL FOR MINERAL RESERVE ESTIMATION BY ORDINARY KRIGING METHOD

This study aims to determine the most suitable model for reserve estimation of a lignite mine in Tavşanlı district, Kütahya, using the Ordinary Kriging (OK) method. Eleven different variogram models were tested, assuming isotropic data, with and without trend removal. Data were normalized through skewed and logarithmic transformations before variogram modeling. The effects of these factors on geostatistical estimation were evaluated statistically. Results showed that the best estimations for the upper and lower surfaces of the lignite reserve were achieved by applying the OK method with skewed distribution data, after removing the trend effect, and using the Hole Effect variogram model. For surface value estimation, the best regression lines between measured and predicted coal depths were y = 0.998x + 0.92 (upper surface) and y = 0.994x + 3.45 (lower surface), indicating high accuracy. Based on the selected method, the lignite reserve in the study area was estimated at approximately 44 million m³.