watersystems
vesistöalueet
flodområden
avrinning
runoff
valunta
catchment areas
catchment basins
water catchments
valuma-alueet
watercatchment areas
drainage basin
catchments
drainage areas
drainage basins
watersheds [Am]
an area drained by a stream
valuma-alue
watersheds
tillrinningsområden
area
alue
functional area
toiminnallinen alue