Scenario-based research simulation. Not an official flood warning or evacuation system.

26 Aug 2026 outburst flood Surge building in the upper valley Modeled replay T+00 min Sediment-laden water following the Bhote Koshi-Trishuli corridor

loading Reference reconstruction

ReplayWatch the flood move through the valley.
ChangeModify breach, rainfall and debris conditions.
SimulateRun an interactive scenario.
CompareSee how downstream impacts change.

Nepal 2026 Flash Flood

A 3D digital twin and what-if simulator for the Rasuwagadhi, Timure, Syabrubesi, Betrawati, Devighat, Galchhi, Malekhu and lower Trishuli downstream corridor.

Source to Downstream

Timeline

T+0

T+00T+30T+60T+120

Layers

Mode 3

What-If Lab

Interactive terrain-constrained scenario approximation. Results are estimated from precomputed hydrograph envelopes and Cesium terrain cross-sections; this is not a newly executed hydraulic solver.

Precomputed scenario Barrier lake volume 2.0-5.0 million m3 Breach mechanism Breach duration Relative breach width Rainfall Antecedent river flow Debris content Channel roughness Bridge condition Secondary blockage

Mode 4

Results / Insights

Asset Inspection

Click a bridge, settlement, road, or facility in the 3D view. Exposure is modeled intersection, not confirmed damage.

Showcase execution

Studio Mission

Powered by Nebula Cloud Studio. Studio orchestrates data, geospatial analysis, engineering simulation, verification and visualization as one executable mission.

Model & Data

Model: Interactive scenario model
Version: nepal-flash-flood-surrogate-v0.1.0
Calibration: Representative / preliminary. Calibration dataset not yet integrated.
Terrain: Cesium World Terrain sampled along the corridor when configured; ellipsoid fallback otherwise.
Infrastructure: OpenStreetMap-derived corridor places plus representative demo asset IDs.
Flood outputs: Representative terrain-constrained inundation surfaces over real geography.
Reference reconstruction: Geopera and Planet Source Cooperative catalogs are cited only; non-commercial imagery/assets are not bundled.
Observed validation: Unavailable. IoU is not reported.

Provenance

Reference event context: Geopera's August 28, 2026 reconstruction reports an approximately 100 million m3 debris-laden release with substantial uncertainty. The smaller 2-5 million m3 barrier-lake controls below are future what-if scenarios, not the August 26 event.