| The hydrological cycle is powered by solar energy. The sun heats water from the ocean, lakes, rivers and the Earth’s surface. This water then evaporates into the atmosphere. Additional water is drawn from the soil by plants, and is then evaporated into the atmosphere from leaves and stems. This process is called transpiration. As the air rises and the temperature drops, the moisture-laden air condenses, forming clouds and eventually resulting in precipitation in the form of rain or snow. Surface run-off makes its way back to the ocean via rivers. Other water seeps into the soil. This process is called infiltration. If the rock below the soil is permeable, then the water percolates the rock and is stored as groundwater. | 
