Integration of Morris and GLUE methods for improving massflow-based debris flow simulation

Debris flow is a common geologic hazard in mountainous areas. It is crucial to simulate its initiation, flow, and accumulation efficiently and accurately for disaster prevention and control. Parameter determination in simulations is quite subjective. To address this issue, the paper presents a simulation approach using the Morris and GLUE methods. The Morris sensitivity analysis is used to identify the sensitive parameters of the Massflow model. The GLUE method is used to calibrate the sensitive parameters and determine the optimal parameter set. Finally, the determined parameter set is employed to simulate the debris flow in Massflow. To validate the effectiveness of this method, Huangyang gully is selected as the case study. The Results show that (1) Rainfall is the most significant factor affecting Massflow simulation results, followed by the channel bed roughness coefficient. (2) The calibrated parameter set improves simulation accuracy from 64 to 76.22%. (3) As the rainfall probabilities decrease, the debris flow accumulation area expands significantly. The largest increase occurs when the area grows from 30,712 m2 for the AEP of P = 2% to 46,272 m2 for the AEP of P = 1%, a 22.7% increase. The simulation results show that the debris flow simulation method based on Morris and GLUE significantly enhances model accuracy. It provides technical support and a scientific foundation for debris flow disaster simulation and prevention.