Himalayan Catchment Surge Simulator Nepal GLOF/LDOF

Peak Discharge (Q_max)
2,840 m³/s
Wave Front Velocity
11.4 m/s
Flood Crest Pos.
Km 8.4 (Gorge)
Lead Time (Village Plain)
34 min 12 s
High-Gradient Catchment Valley Profile (4,800m → 800m)
Sim Time: 00:00:00
Click / Drag profile to inspect elevation & station cross-section
Multi-Station Hydrograph Telemetry (Discharge m³/s vs Time) Kinematic Wave Routing
Catchment Settlement Risk & Evacuation Thresholds
Station / Settlement Elev. Distance Est. Arrival Peak Stage Status / Action
Disaster Presets
Cloudburst Precipitation Rate 85 mm/hr
Antecedent Soil Moisture Saturation 78%
Breach / Outburst Volume (GLOF/LDOF) 4.2 M m³
Manning's Bed Roughness (n) 0.062 (Boulder Choke)
Catchment Basin Area 340 km²
Debris / Sediment Entrainment Ratio 35% Bulking
Mechanics & Hydrology Model

Steep Valley Hydrodynamics

In steep Himalayan catchments (>35° headwaters to 8° valley floors), flood surge attenuation behaves fundamentally differently from lowland rivers. Supercritical flow regimes (\(Fr > 1\)) and massive debris entrainment (up to 50% sediment volume) induce hyper-concentrated slurry waves that resist normal kinematic diffusion.

Early Warning Window

Surge fronts traveling at 8–15 m/s compress acoustic and sensor lead times. As seen in Nepal's Melamchi (2021) and Seti River (2012) tragedies, moraine dam breaches create rapid cascading chokes where flood heights surge 12+ meters above baseline in less than 15 minutes.