A Prediction Method for Floor Water Inrush Based on Chaotic Fruit Fly Optimization Algorithm–Generalized Regression Neural Network

Table 1

Relationship between aquifuge thickness and number of water inrush in typical mining areas.

Aquifuge thickness (m)	Number of water-inrush events	Proportion (%)
>40	23	7
32-40	34	10
25-32	96	28
20-25	77	22
<20	113	33