Main Features (Parts) of the Hydrological Cycle:
- Evaporation
- Water changes from liquid to gas (vapour) due to heat from the sun.
- Happens in oceans, rivers, lakes.
- Transpiration
- Plants lose water through their leaves into the air.
- This water becomes vapour in the atmosphere.
- Condensation
- Water vapour cools down and changes back into liquid, forming clouds.
- Precipitation
- Water falls back to the Earth as rain, snow, sleet, or hail.
- Runoff
- Rainwater flows over the land into rivers and lakes.
- Infiltration
- Some rainwater soaks into the ground, becoming groundwater.
- Percolation
- Water moves deeper through soil and rocks, feeding underground sources.
- Collection
- Water gathers in oceans, lakes, rivers, and the cycle starts again.
Distribution of water on Earth:
|
Source of Water |
Percentage |
|
Oceans and seas |
97% |
|
Freshwater (ice, lakes, rivers) |
3% |
|
Usable freshwater |
Less than 1% |