Hydrologic Cycle: a brief description
The hydrologic cycle begins with the evaporation of water from the surface of the ocean. There are five processes at work in the hydrologic cycle: condensation, precipitation, infiltration, runoff and evapotranspiration. These occur simultaneously and, except for precipitation, continuously. Together, these five processes make up the Hydrologic Cycle. Water vapor condenses to form clouds, which result in precipitation when the conditions are suitable. Precipitation falls to the surface and infiltrates the soil or flows to the ocean as runoff. Surface water (e.g., lakes, streams, oceans, etc.), evaporates, returning moisture to the atmosphere, while plants return water to the atmosphere by transpiration. Condensation is the process of water changing from a vapour to a liquid. Water vapour in the air rises mostly by convection. This means that warm, humid air will rise, while cooler air will flow downward. As the warmer air rises, the water vapour loses energy, causing its temperat...