Fluvial landforms of streams forest Geological phenomenon landscape Natural landscape nature stream water water resources watercourse waterfall waterway bank clean flow green mountain norway plant river rocks tree cloud sky canal grass Land lot branch natural environment vegetation biome environment habitat rain rainforest rock Singapore Terrestrial plant tropical trunk cascade Forrest Mountain River outside hiking Riparian zone architecture botany bridge garden leaf royal Body of water cliff Ecoregion highland milford sound new zealand algae fluid lake moss spring hut shed village wooden