Field-based discharge measurements across seven major transboundary rivers shared between Nepal and India — generating ground-truth data to validate satellite estimates from NASA's Surface Water and Ocean Topography (SWOT) mission.
Using Acoustic Doppler Current Profiler (ADCP) instruments deployed from boats and bank stations, the team measured cross-section velocity profiles, flow depth, and discharge rates — providing critical reference data for cross-border water resource management.
Sends acoustic pulses through the water column to measure velocity at multiple depths simultaneously. Mounted on inflatable boats and traversed across the river to build a full velocity field.
High-precision GNSS receivers track the boat's path and water surface elevation in real time, enabling accurate cross-section geometry needed for discharge calculations.
Independent depth verification ensures the channel geometry is captured accurately — critical where bed sediment or vegetation can obscure ADCP returns.
Post-processing scripts for cross-section interpolation, depth-averaged velocity calculation, and discharge integration using established hydrometric methods.
NASA's SWOT mission, launched in 2022, measures river width and water surface elevation from space — but converting those measurements into discharge requires prior estimates from in-situ field data. That's where this project fits in.
Nepal's transboundary rivers feed millions of people across South Asia. Reliable discharge data underpins cross-border water-sharing agreements, hydropower planning, and flood early warning. Field measurements like these turn satellite data into actionable hydrology.
Photographs from the river survey campaigns are available in the gallery.
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