Layer: Nepal-Origin Routes To Ocean

Explorer label: Ocean route
Layer group: Hydrology and basin layers
Feature count: 4

HydroRIVERS downstream traces continuing Nepal-linked systems through the Ganges/Padma/Meghna route to the Bay of Bengal.

Summary

This layer extends Nepal-linked downstream-system traces through the Ganges, Padma, and Meghna route toward the Bay of Bengal. It is a topology layer for following Nepal-origin systems beyond the northern plains.

What It Represents

This layer extends the existing Layer: Nepal-Origin Downstream Systems beyond the northern plains. It lets the reader follow each Nepal-linked system through the larger Ganges network toward the Bay of Bengal.

The four route features are:

Route	Origin system	Merge system
Koshi route to Bay of Bengal	Koshi-Kosi	Kosi-Ganges-Padma-Meghna
Gandaki route to Bay of Bengal	Gandaki-Narayani-Gandak	Gandak-Ganges-Padma-Meghna
Karnali route to Bay of Bengal	Karnali-Ghaghara	Ghaghara-Ganges-Padma-Meghna
Mahakali route to Bay of Bengal	Mahakali-Sharda	Sharda-Ghaghara-Ganges-Padma-Meghna

How To Read It

Use this as a strategic continuity layer. The existing downstream-system lines show Nepal-to-plains routing; this layer shows how those systems enter the shared lower Ganges route and ultimately reach the Bay of Bengal.

Important fields:

Field	How To Use It
`merge_system`	Names the downstream trunk each Nepal-linked route joins.
`route_confidence`	Indicates how confidently the current downstream endpoint snapped to HydroRIVERS.
`snap_distance_km`	Shows the distance between the existing mapped endpoint and the HydroRIVERS route start.
`route_length_km`	Approximate downstream route length in the generated trace.
`source_method`	Records the HydroRIVERS `NEXT_DOWN` tracing method.

Coverage / Method

The layer covers 4 generated route features. Routes are traced from existing Nepal-linked downstream-system endpoints using HydroRIVERS NEXT_DOWN topology, with route confidence, snap distance, route length, and method fields documented in downstream_ocean_route_report.json.

Caveats

This is a topology and communication layer, not a hydrodynamic model. It does not represent reservoir operations, flow volumes after withdrawals, distributary splits, tidal dynamics, embankments, barrages, irrigation diversions, or floodplain storage.

Dense delta distributaries are intentionally out of scope for the current layer. It preserves one strategic trunk per Nepal-linked system so the reader can follow the basin story without turning the map into a complete delta-network inventory.

Linked Data

nepal_origin_ocean_routes.geojson - generated route layer.
downstream_ocean_route_report.json - route QA report.