InSAR-Informed 3D Glacier Dynamics and Multi-Phase Simulation for Quantifying Cascading GLOF Risks in the Southeastern Tibetan Plateau

<title>Abstract</title> Glacial Lake Outburst Floods (GLOFs) are intensifying under accelerating climate change, posing severe threats to high-mountain communities and downstream infrastructure. However, current approaches often lack early-stage hazard detection and fail to simulate the full cascade of related processes. This study presents an integrated framework combining InSAR-based 3D glacier deformation monitoring with multi-phase numerical modeling to assess cascading GLOF processes in the southeastern Tibetan Plateau. Time-series analysis of Sentinel-1 SAR data revealed a fourfold increase in glacier terminus ablation (10–50 cm/yr from 2019 to 2024 signaling progressive moraine dam instability. The framework combines three-dimensional computational fluid dynamics (CFD) simulations to capture the complete hazard chain, from moraine dam breach to debris flow propagation and deposition. Under a modeled10-meter breach scenario, the peak discharge reached 3581 m³ s⁻¹, with velocities exceeding 60 m s⁻¹ in confined downstream channels. The simulations captured dynamic erosion–deposition patterns and variable runout distances, highlighting non-linear energy transfer throughout the cascade. Cross-model comparisons yielded consistent peak discharges but divergent deposition patterns, largely due to differing rheological and entrainment assumptions. Sensitivity analyses highlighted dam height, channel slope, and sediment entrainment rate as critical drivers. Based on spatiotemporal modeling outputs, impact zones were delineated, and early warning lead times were estimated to be as short as 5 minutes. Our results offers a globally transferable, physics-informed approach for real-time GLOF forecasting and climate-resilient risk mitigation in cryosphere-dominated landscapes.