Chinese name: hydrologic cycle English name: hydrologic cycle; hydrological cycle Other names: water cycle (water cycle) Definition 1: the earth's surface water in the role of solar radiation, evaporation and rise, cold condensation, in certain conditions, in the form of precipitation falls to the earth's surface in the form of gravity, the continuous movement, and then re-generate evaporation, condensation, precipitation and runoff and other cyclical changes. The process of evaporation, condensation, precipitation and runoff is repeated. Applied disciplines: geography (first level); hydrology (second level) Definition 2: The cyclical movement of water on Earth between the atmosphere, land and sea by evaporation, precipitation and runoff under the action of solar radiation and gravity. Includes the global water cycle and the local water cycle. Applied disciplines: Water Science and Technology (first level); Hydrology and Water Resources (second level); Hydrology (water resources) (third level) Definition 3: The round-trip process by which atmospheric precipitation enters the atmosphere again through evaporation and transpiration. Applied disciplines: Soil Science (first level); Soil Physics (second level)