也称“水分循环”。地球上的水分受太阳辐射、重力等作用影响在大气中蒸发、凝结、降落的循环过程hydrological cycle

• 雨水利用是从水文循环中获取水为人类所用的一种方法。

  Rainwater usage is a way for people to gain access to water in the hydrological cycle.

• 世界气象组织拥有全球观测系统、大气观测系统和水文循环观测系统。

  The World Meteorological Organization has a global observation system, an atmospheric observation system, and a hydrological cycle observation system.