Determining the Height of Water-Flowing Fractured Zone in Bedrock-Soil Layer in a Jurassic Coalfield in Northern Shaanxi, China

Table 5

Comparison between the results obtained by microresistivity scanning imaging and simple hydrology observation of soil layer.

Drilling	Interpretation of fractures by microresistivity scanning imaging		Fractures of simple hydrological observation				Comparative results	Ratio of the water-flowing fractured zone to the mining height
	Depth of the fractures (m)	Fracture numbers/article	Depth of the fractures (m)	Water level existence	Rate of water level decline (m∙min^-1)	Drilling flushing fluid consumption per unit time (L∙s^-1)
Drilling 8	21.8	2	21.92	No	—	1.3	No water level; total pump leakage. The rock mass is broken. Those two methods confirm each other better	28.5
	29.9		29.12	No	—	1.3
Drilling 9	7.8–7.9	4	7.79	Yes	0.026	0.6933	The water level declines to zero and the rate of decline suddenly changes	28.3
	18.4		16.67	Yes	0.380	0.7917	No water level; total pump leakage. Those two methods confirm each other better
	22.4		22.97	No	—	2.0742