voolava vee erosiooni tagajärjel kujunenud, varieeruvate mõõtmetega (laius, sügavus), lineaarne piklik negatiivne pinnavorm, has a diverse shape and measures, usually a narrow negative linear landform (with a stream running through it). Different shape of the cross profile (V-shape, U-sape, canyon; flood-plain valley) is due to differences in discharge, flow velocity and geological setting.