Watershed Delineation Tool

Delineate catchments, trace flow paths, and monitor live river & reservoir data across India

Analysis Controls
Click a point on the map
Select an outlet to begin delineation
Map Layers
Min stream order5
1 = all streams  ·  6 = major rivers only
India Datasets
Flood Monitoring
Reservoir Monitoring
These datasets are not owned by NIH / NIH-DHAARA — they belong to their respective official agencies (CWC / India-WRIS). Use them as per your own understanding; click for source details.
Results

Select an outlet point and run Delineate, Trace Flow, or Batch to view results

How to Use
  1. Choose Delineate, Trace Flow, or Batch mode
  2. Click a point on the map, or enter coordinates
  3. Click the Run button to compute results
  4. Toggle Map Layers for river networks, stations, and live monitoring
Datasets & Methodology

The Delineation tool utilizes high-precision global and national datasets to extract catchment details:

1. MERIT-Hydro DEM

A high-resolution (3 arc-second, ~90 m) global hydrography dataset. It improves on MERIT DEM by correcting stripes, tree canopy height, and topographic errors using ancillary datasets.

Used for: D8 flow direction raster calculations, flow path tracking, and catchment bounds extraction.

2. HydroBASINS (WWF / HydroSHEDS)

Pre-delineated watershed boundaries mapped at nested Pfafstetter topological levels, ensuring globally standardized catchment definitions.

Used for: Fast sub-basin identification, Pfafstetter nesting index mapping, and regional boundaries.

3. India-WRIS Network

Official datasets from the India Water Resources Information System containing standardized river channels, states/districts, and Gauge & Discharge stations.

Used for: Snapping outlet markers to historical measurement locations and regional overlays.

4. CWC Flood Watch

Central Water Commission's real-time water level observations and flood warning telemetry scraped directly from CWC portals.

Used for: Overlaying current active flood warnings and level alerts over catchments.

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