Cognised existence: Surface freshwater bodies are the visible hydrological features of the landscape — rivers, streams, lakes, ponds, reservoirs, and canals. They are both ecological habitats and infrastructure.
Question: What surface freshwater bodies exist at a location and how do they flow?
OSM wiki: https://wiki.openstreetmap.org/wiki/Key:waterway | https://wiki.openstreetmap.org/wiki/Tag:natural%3Dwater
Realisations
OpenStreetMap — waterway=*, natural=water
OSM covers rivers, streams, lakes, and canals globally. Linear waterways are tagged on ways; standing water bodies on closed ways or relations.
osmnx access
import osmnx as ox
ox.settings.cache_folder = ".cache/"
# Rivers and streams (linear)
waterways = ox.features_from_place(
"Copenhagen, Denmark",
tags={"waterway": ["river", "stream", "canal", "drain"]}
)
# Lakes and ponds (polygon)
water_bodies = ox.features_from_place(
"Copenhagen, Denmark",
tags={"natural": "water"}
)Geofabrik layers
| Layer | Content |
|---|---|
gis_osm_waterways_free_1.shp | Rivers, streams, canals — LineString |
gis_osm_water_a_free_1.shp | Lakes, ponds, reservoirs — Polygon |
Key OSM tags
| Tag | Meaning |
|---|---|
waterway=river | River |
waterway=stream | Stream |
waterway=canal | Canal |
waterway=drain | Drainage channel |
natural=water | Water body (lake, pond, reservoir) |
water=lake | Lake (sub-tag of natural=water) |
water=reservoir | Reservoir |
water=pond | Pond |
name=* | Name of the water body |
Natural Earth — Lakes and Rivers
Natural Earth includes ne_10m_lakes, ne_10m_rivers_lake_centerlines, and related ocean basin polygon variants at three scales. Best used for continental or global overview contexts.
Python load
import geopandas as gpd
lakes = gpd.read_file("ne_10m_lakes.shp")
rivers = gpd.read_file("ne_10m_rivers_lake_centerlines.shp")
# Optional: filter to major rivers only
major_rivers = rivers[rivers["scalerank"] <= 4]Key attributes
| Field | Meaning |
|---|---|
featurecla | Feature class (Lake, River) |
name | Feature name |
scalerank | Prominence rank (lower = larger/more important) |
min_zoom | Suggested minimum display zoom |
Geometry Representations
| Rep ID | Source Dataset | Geometry Type | Native CRS | Suitable For | Not Suitable For |
|---|---|---|---|---|---|
freshwater_osm_lines | OSM via Geofabrik | LineString | EPSG:4326 | Network tracing, flow direction, river mapping | Catchment area calculation |
freshwater_osm_polygons | OSM via Geofabrik | Polygon | EPSG:4326 | Surface area, shoreline mapping | Flow routing, upstream/downstream analysis |
freshwater_ne_10m_lakes | Natural Earth 10m lakes | Polygon | EPSG:4326 | Global lake context, continental overview | Small or sub-regional lake detail |
freshwater_ne_10m_rivers | Natural Earth 10m rivers and lake centerlines | LineString | EPSG:4326 | Global/continental river context, atlas mapping | Tributary-level hydrological analysis |
Important: For catchment / drainage basin analysis, a DEM-derived hydrological network (e.g. Copernicus DEM + SAGA/WhiteboxTools) is more reliable than OSM waterways.
Limitations
- Small streams are under-mapped in many regions.
- Flow direction is implied by way direction but not always correct.
- For hydrological modelling, supplement with DEM-derived data.
Realised By Links
- OpenStreetMap (collection)
- Natural Earth (collection)