The diagram illustrates the hydrological cycle, showing how water circulates continuously between the Earth’s surface and the atmosphere.
Overall, the process is cyclical and consists of several main stages, beginning with evaporation and ending with the return of water to rivers and oceans through precipitation and surface runoff.
At the first stage, heat from the sun causes water from oceans, lakes and rivers to evaporate, turning it into water vapour. Plants also contribute to this process through transpiration, releasing moisture into the atmosphere. The water vapour then rises and cools, leading to condensation, during which clouds are formed.
As the clouds become heavier, precipitation occurs in the form of rain or snow. Part of this water flows over the land as surface runoff, eventually reaching rivers, lakes and seas. Meanwhile, some water infiltrates the soil and becomes groundwater, which slowly moves underground and later returns to surface water bodies.
This continuous movement of water ensures the constant recycling of Earth’s water resources.