IB ESS SL 4.1: Introduction to Water Systems

Study Notes

Fresh Water Statistics

Approximately 68.7% of Earth's fresh water is stored in glaciers and ice sheets.
The remaining 1.3% of fresh water is found in various sources, including soil moisture, groundwater, and surface water bodies.
Only about 2.5% of all water on Earth is fresh water, while the vast majority (97.5%) is saltwater.

Hydrological Cycle

The hydrological cycle describes the continuous movement of water within the Earth and atmosphere.
Key processes in the hydrological cycle include evaporation, condensation, precipitation, infiltration, runoff, and transpiration.

Processes in the Hydrological Cycle

Evaporation: The transformation of liquid water into vapor, leading to water vapor entering the atmosphere.
Condensation: The conversion of water vapor back into liquid water, forming clouds.
Precipitation: Water falling from clouds in various forms, such as rain, snow, or hail.
Infiltration: The process of water soaking into the soil and becoming groundwater.
Runoff: The movement of water, typically from precipitation, that flows over the land surface into bodies of water.
Transpiration: The release of water vapor from plants into the atmosphere.

Storages in the Hydrological Cycle

Major storages include oceans, glaciers, ice caps, groundwater, lakes, rivers, and the atmosphere.

Flows in the Hydrological Cycle

The flows consist of processes that move water between different storages, including evaporation, precipitation, runoff, and infiltration.

Additional Resources

Further information and resources related to the hydrological cycle and fresh water can be found in scientific literature, environmental organizations, and educational websites.

Description

Test your knowledge on the Introduction to Water Systems topic of IB Environmental Systems & Societies (ESS) SL 4.1. Explore the Hydrological Cycle, Human Impact on the Hydrological Cycle, and Ocean Circulation.