Constructing rainfall thresholds for debris flow initiation based on critical discharge and S-hydrograph

Debris flows caused by channel bed erosion present major hazards affecting life, livelihoods, and the built environment in mountainous regions. An efficient way to decrease hazard impact is through reliable forecasts appropriate early-warning strategies. Rainfall thresholds are fundamental achieving forecasts. However, a lack of rainfall records often impedes empirical establishment such thresholds. This paper constructs intensity-duration based on process-based critical runoff discharge for initiation debris mathematical approximation among peak discharge, intensity duration. Simulations conditions that triggered flow non-debris events allowed determination lower upper limits initiation. In turn, these compared with four estimates derived from approaches test which approach best delimit conditions. Hydrological simulations derive S-hydrographs recorded events. Further analysis results as function duration minimum required produce particular discharge. The threshold trigger an event can be calculated setting dis charge. this enables conventional I-D construction valley-specific data-poor areas provides promising pathway improve reliability early warnings.