Water & Enviro Week 1

How much of Earth’s surface is covered in water

70%

Humans use how much freshwater

200000km3

True or false: Freshwater is available for use evenly around the planet

False

5 Stages of Hydrological Cycle

1. Evaporation / Evapotranspiration

2. Condensation

3. Precipitation

4. Infiltration

5. Runoff

Evaporation / Evapotranspiration

Water transferred from earth’s surface to atmosphere via evaporation of liquid/solid water & transpiration from plants

What percentage of atmospheric water comes from evaporation

90%

Evapotranspiration

Plants take water through roots - vaporisation occurs within intercellular spaces in leaves

Condensation

Transformation of water vapour to liquid droplets in the air producing clouds

Precipitation

Discharge of water in liquid/solid state out of the atmosphere

Infiltration

Penetration of water into soil & pores of permeable rocks

Zone of aeration

Gaps in sand, soil, rocks contain air and water

Zone of saturation

Gaps completely filled with water

Confined aquifer

Groundwater sandwiched by impermeable layers (aquitards) prevent passage of contaminants into aquifer

Unconfined aquifer

No overlying impermeable layer protecting aquifer - prone to contamination

Runoff

Movement of water over earth’s surface towards streams, rivers, lakes, oceans & depressions

Drainage basins

Lan where runoff drains downhill to a common point

True of false: Runoff flow picks up nutrients, sediments & pollutants which can be deposited into rivers, lakes etc causing ecological impact

True

In 2024, out of had safe drinking water

3 out of 4

People in less developed countries are ___ as likely to have access to clean water

Twice

How many people lack safely managed drinking water services

2.1 billion