Topic 1: Foundation

1.1 Perspectives

1.2 Systems

1.3 Sustainability

Topic 2: Ecology

2.1 Individuals, populations, communities, and ecosystems

2.2 Energy and biomass in ecosystems

2.3 Biogeochemical cycles

2.4 Climate and biomes

2.5 Zonation, succession and change

Topic 3: Biodiversity and conservation

3.1 Biodiversity and evolution

3.2 Human impact on biodiversity

3.3 Conservation and regeneration

Topic 4: Water

4.1 Water systems

4.2 Water access, use and security

4.3 Aquatic food production systems

4.4 Water pollution

4.4.1—Water pollution sources

4.4.2—Plastic debris accumulation

4.4.3—Water quality measurement

4.4.4—Biochemical oxygen demand (BOD)

4.4.5—Eutrophication

4.4.6—Eutrophication sequence

4.4.7—Eutrophication and ecosystem services

4.4.8—Eutrophication management levels

4.4.9 (HL)—Water pollutants

4.4.10 (HL)—Harmful algal blooms

4.4.11 (HL)—Anoxic and hypoxic waters

4.4.12 (HL)—Sewage treatment stages

4.4.13 (HL)—Indicator species

4.4.14 (HL)—Biotic index

4.4.15 (HL)—Water Quality Index (WQI)

4.4.16 (HL)—Water quality guidelines

4.4.17 (HL)—Citizen action

Topic 5: Land

5.1 Soil

5.2 Agriculture and food

Topic 6: Atmosphere and climate change

6.1 Introduction to the atmosphere

6.2 Climate change—causes and impacts

6.3 Climate change—mitigation and adaptation

6.4 Stratospheric ozone

Topic 7: Natural resources

7.1 Natural resources—uses and management

7.2 Energy sources—uses and management

7.3 Solid waste

Topic 8: Human populations and urban systems

8.1 Human populations

8.2 Urban systems and urban planning

8.3 Urban air pollution

HL.a Environmental law

HL.b Environmental economics

HL.c Environmental ethics

IB ESS HL 4.4.15 (HL)—Water Quality Index (WQI) Question Bank

• Single weighted average of multiple test parameters

• Represents contamination degree

0 selected