Risk Assessment of Water Inrush in Coal Seam Floor Based on a Dynamic Variable Weight Model and 3D Probability Space Comparison

Mining under the Ordovician limestone aquifer is severely threatened by coal seam floor water inrush, which endangers mining safety. Traditional fixed-weight evaluation models for coal floor water inrush risk have prominent limitations: they ignore the internal variability among index values, easily distorting prediction results and failing to meet the demand for accurate risk assessment. To address this issue, this study proposes a dynamic variable weight evaluation model for coal floor water inrush risk based on the Improved Fuzzy Analytic Hierarchy Process (IFAHP) and Entropy Weight Method (EWM). First, after comprehensive analysis of hydrogeological data, six key evaluation indicators were selected, including Ordovician limestone water pressure, Ordovician limestone water abundance, aquifuge thickness, fragile rock ratio, fault fractal dimension, and floor failure depth. Subjective weights from IFAHP and objective weights from EWM were then combined to obtain comprehensive weights. Subsequently, the K-means algorithm was applied for unified clustering analysis of the indices to define variable weight intervals and construct the dynamic variable weight model. Based on this model, ArcGIS was used to classify Ordovician limestone water inrush risk into four levels and generate a risk zoning map for the 16<sup>th</sup> coal seam floor. Validation with known water inrush points and comparative analysis with the constant-weight model demonstrated that the proposed IFAHP-EWM dynamic variable weight method has higher prediction accuracy and better spatial adaptability. Additionally, 3D visualization of the risk zoning map was developed to enhance practical application. This model provides a reliable theoretical basis and practical tool for improving the safety of coal seam floor mining under Ordovician limestone aquifers.