Quantitative Evaluation for the Threat Degree of a Thermal Reservoir to Deep Coal Mining

Table 17

Relative difference matrix of borehole Qs1.

Index factor	Threat level
	Safe (I)	Low threat (II)	Medium threat (III)	Relatively high threat (IV)	High threat (V)
	-1	-0.0171	0.0171	-1	-1
	-1	-1	-1	0.5291	-0.5292
	-1	-1	-1	-1	-1
	-1	-1	-0.8808	0.8821	-1
	-1	-1	-1	0.3162	-0.3162
	-1	-1	0.39	-0.39	-1
	-1	-1	-0.6218	0.6242	-1
	-1	-0.5081	-0.6204	0.6203	-1