Determining the optimum search range for 2D and 3D mapping based on kriging through quantitative analysis

As the best linear estimator, kriging is now a well-established method in all types of 3D geomodelling, including geochemical mapping, rock type modelling, 2D geophysical mapping, and resource estimation. In this context, investigating kriging performance has always been of interest to numerous researchers. Evaluating kriging implementation for different applications has been a growing field of study in the last few decades. Although many authors have discussed various kriging parameters, it seems necessary to conduct more detailed studies on range searching, high and low nugget effect, as well as 2D and 3D estimations. In this paper, an optimal search range was determined using Quantitative Kriging Neighbourhood Analysis (QKNA), and the utility of this search range was explored by assessing kriging efficiency. Because of the existence of different numerical measures of search ranges in each criterion, it is difficult to define the optimal search range of an estimation process. In this research, different Multiple Criteria Decision Making (MCDM) methods were employed to determine the optimal search range via QKNA and by considering criteria which were applied to different cases. Given the unique capacity of this method in meeting this challenge, the Fuzzy-TOPSIS method, a variant of MCDM, was used in this study.