What is the hydrological cycle?
• Around 98 per cent of the water on Earth lies in the seas and is therefore saline. Powered by solar energy, seawater and other surface waters evaporate and form clouds. These clouds condense and provide freshwater in the form of precipitation. Under the force of gravity, freshwater makes its way back towards the seas in rivers and as groundwater, serving the needs of living organisms on the way. From the sea it again evaporates and the process repeats itself.