Topographic map of the Kymi river basin.
Own work

Topography: Elevation model 2 m / National Land Survey of Finland (open data, CC BY 4.0)
Labels: Geographic names / National Land Survey of Finland (open data, CC BY 4.0)
Drainage basins: Catchment Areas / Finnish Environment Institute (open data, CC BY 4.0)
Shoreline, Lakes, Cities: Topographic map 1:250 000 / NLS National Land Survey of Finland (open data, CC BY 4.0)
Rivers: Shoreline - River Network (Ranta10) / Finnish Environment Institute (open data, CC BY 4.0)
Relief: Digital Elevation Model over Europe (EU-DEM) / European Environment Agency
Inset map: 1:10m Cultural – Admin 0 – Countries / Natural Earth
ETRS89 / ETRS-TM35FIN Transverse Mercator projection
Nelg