Application of Classification and Systematization Methods in Assessment of the Level of Associated Hazards in the Exploitation Areas

In Polish coal mines as the extraction descents to the increasing depth, the risk of methane and spontaneous fire is observed. The coexistence of these two hazards enforces at the design phase and during extraction, the assessment in terms of the selection of a prevention scope for their eradication. Based on a set of indicators and parameters describing the level of co-occurrence of both threats on a set of 75 longwalls extracted in Polish hard coal mines, their classification and systematization was performed with the use of statistical methods. Adoption of the methods described in the publication made it possible to split the set of 75 longwalls into statistically homogeneous subsets, characterizing similar longwalls, and the development of a synthetic evaluation instrument, with the coexistence of hazards allowed to calculate for each longwall its dimensionless value that is a reflection of the level of associated risk. The calculation results reflect with high probability the actual level of associated hazards when mining these longwalls.