水すい界かい

noun

hydrosphere

Scientific term for the total water on Earth's surface, including oceans, lakes, rivers, and groundwater. Often used in earth science contexts.

See also: 水圏

• 水すい界かいは地ち球きゅうの表ひょう面めんの約やく70%を覆おおっている。

  The hydrosphere covers about 70% of the Earth's surface.

noun

boundary between water and land

Refers to the interface or border where water meets land, such as a shoreline or riverbank. Less common than the hydrosphere sense.

• 水すい界かいには多た様ような生いき物ものが生せい息そくしている。

  Diverse organisms inhabit the boundary between water and land.