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.
Leaves
| Leaf | Question | Lens | Connection |
|---|---|---|---|
| Bathing Water Quality | Is bathing water suitable and safe for human recreational use at this location and time? | primary | Bathing suitability is interpreted against the local freshwater surface context and station placement. |
| Drinking Water & Water Source Protection | What drinking water source protection zones or supply infrastructure exist here? | member | |
| Elevation | What is the elevation at a given location? | member | Elevation gradients govern runoff and flow paths in freshwater systems. |
| Flood Hazard and Inundation | Which areas are exposed to flooding or inundation here, and under what scenario or return period? | member | |
| Hydrological Basin Delineations | Which basin or sub-basin does this location belong to in water-management planning? | primary | |
| Surface Flow Systems | How does water move and accumulate on the surface here, including depressions, flooding, and catchment context? | primary | |
| Surface Freshwater Bodies | Which river, lake, wetland, or catchment is this location part of? | primary |
Classical Theme Mappings
| Standard | Theme | Link |
|---|---|---|
| ISO 19115 | Inland Waters | Inland Waters |
| INSPIRE | Hydrography | Hydrography |
| UN-GGIM | Water | Water |