Layer: Nepal-Linked Basin Polygons

Explorer label: Basin areas
Layer group: Hydrology and basin layers
Feature count: 4

Koshi, Gandaki, Karnali, and Mahakali upstream basin polygons, with Nepal share and monsoon context.

Summary

This layer contains the Koshi, Gandaki, Karnali, and Mahakali upstream basin polygons used by the explorer. It gives the map broad hydrological boundaries for reading Nepal's upstream position, basin shares, and monsoon context.

What It Represents

This layer frames Nepal as an upstream hydrological actor. The polygons show the major Himalayan systems whose water, sediment, and seasonal flows pass through or originate in Nepal before entering the wider Ganges plain. The layer is not just a geography overlay; it is the base for understanding where Nepal has physical leverage and where that leverage is limited.

How To Read It

Read basin area together with Nepal share and monsoon share. A large basin with high Nepal share indicates stronger upstream relevance for Nepal planning; a shared or border basin requires more geopolitical caution. The layer is especially useful before turning on project or downstream-impact overlays.

Coverage / Method

The layer covers 4 basin polygon features listed in Map Inventory. It packages basin geometry with contextual fields such as Nepal share and monsoon share for explorer-scale comparison rather than sub-basin modeling.

Caveats

Basin polygons simplify complex hydrology. They do not resolve treaty rights, engineering control, reservoir operations, environmental flows, or sub-basin heterogeneity. The polygons should be read as analytical boundaries, not as claims of unilateral control.