Temporal and Spatial Evolution Mechanisms of the Water-Conducting Fractured Zone of Overlying Strata in the Kongzhuang Coal Mine

Table 2

Danger zone table of water intrusion.

Roof type area	Water inrush risk index (TS)
Safe area	<0.36
Safer area	(0.36, 0.44)
Transition area	(0.44, 0.51)
More dangerous areas	(0.51, 0.60)
Danger zone	>0.60