Rivers, lakes, wetlands, reservoirs, and drainage systems — the visible freshwater on the land surface. This is the twig for hydrographic data describing water bodies, their flow, and their characteristics.
Scope
- Rivers and streams: Channel geometry, streamflow measurements, catchment boundaries, stream order
- Lakes and ponds: Extent, depth, volume, water level monitoring
- Wetlands: Bog, fen, marsh classification and delineation
- Reservoirs: Artificial water bodies, dam locations, storage capacity
- Drainage: Drainage networks, tile drain systems, storm drainage routes
- Estuaries: Transitional waters where freshwater meets marine (shared with Marine)
Key Distinction: Water Body vs Water Quality
This twig describes the water body itself — its geometry, flow, and physical state. The quality of the water (pollutant concentrations) is Hydrosphere Contaminants. The organisms in the water are Biosphere.
Classical Theme Mappings
| Standard | Theme | Link |
|---|---|---|
| ISO 19115 | Inland Waters | |Inland Waters |
| INSPIRE | Hydrography | |Hydrography |
| UN-GGIM | Water | |Water |