FABS 222 Module 4 Lecture 5: Global Water Security

USASK/UOFS

MODULE 4 LECTURE 5: GLOBAL WATER SECURITY

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Water security

Reliable availability of sufficient quantities of safe water for human health, agriculture, ecosystems, and economic production.

Water scarcity

Occurs when water demand exceeds available water resources in a region.

Physical water scarcity

Natural water resources are insufficient to meet human and environmental demand.

Economic water scarcity

Water is available but infrastructure or governance limits access.

Global freshwater availability

Only about 2.5% of Earth’s water is freshwater.

Accessible freshwater

Less than 1% of freshwater is easily available for human use.

Major global water users

Agriculture, industry, and domestic households.

Agricultural water use

Agriculture accounts for about 70% of global freshwater withdrawals.

Industrial water use

Used for cooling, manufacturing, and energy production.

Domestic water use

Includes drinking, cooking, cleaning, and sanitation.

Water footprint

Total volume of freshwater used to produce a product or service.

Blue water footprint

Surface and groundwater used for irrigation or processing.

Green water footprint

Rainwater stored in soil used by plants.

Grey water footprint

Water needed to dilute pollutants to safe concentrations.

Virtual water

Hidden water used during production of food and goods.

Virtual water in food

Meat products require more water than plant foods.

Water footprint of beef

Very high due to feed crops and animal water needs.

Water footprint of cereals

Lower water demand compared to livestock.

Water stress

Water demand approaches or exceeds supply.

Climate change impact on water

Alters rainfall patterns and increases drought risk.

Drought definition

Prolonged period of below-average rainfall.

Flooding effects

Damages crops and contaminates water supplies.

Groundwater

Water stored underground in aquifers.

Aquifer

Underground water-bearing geological formation.

Groundwater depletion

Extraction faster than natural recharge.

Irrigation

Artificial application of water to crops.

Over-irrigation

Excess watering leading to soil problems.

Salinization

Salt buildup in soil from irrigation evaporation.

Waterlogging

Saturated soils reduce oxygen to plant roots.

Water quality

Chemical, physical, and biological condition of water.

Water contamination

Harmful substances introduced into water.

Agricultural runoff

Fertilizers and pesticides entering water bodies.

Nutrient pollution

Excess nitrogen and phosphorus in water.

Eutrophication

Algae growth causing oxygen depletion.

Waterborne pathogens

Disease-causing microbes in water.

Safe drinking water

Water free from pathogens and toxic chemicals.

Water treatment

Processes used to improve water safety.

Primary treatment

Removal of solids by screening and settling.

Secondary treatment

Microbial breakdown of organic matter.

Tertiary treatment

Removal of nutrients and contaminants.

Water reuse

Recycled wastewater used again.

Desalination

Removal of salt from seawater.

Desalination limitation

High cost and energy requirement.

Irrigation efficiency

Percentage of water used by plants.

Drip irrigation

Delivers water directly to roots.

Sprinkler irrigation

Water sprayed over crops.

Flood irrigation

Fields submerged in water.

Water conservation

Reducing water use and waste.

Rainwater harvesting

Collection and storage of rainwater.

Integrated water management

Coordinated use of water resources.

Water governance

Policies controlling water use and distribution.

Sustainable water use

Use that does not exceed replenishment.

Food security and water

Food production depends on water availability.

Population growth and water demand

More people increase water needs.

Urbanization impact on water

Cities increase domestic water demand.

Water-energy-food nexus

Interconnection of water, energy, and food systems.

Water productivity

Crop yield per unit of water used.

Efficient irrigation

Methods that minimize water loss.

Water recycling

Reusing treated wastewater.

Sustainable agriculture and water

Practices reducing water use while maintaining yield.