Lesson Notes By Weeks and Term v5 - Grade 10

Lesson Video

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Performance objectives

• Define and give examples of pollution, resource depletion, and habitat destruction in South Africa.
• Explain the causes and consequences of water and air pollution.
• Evaluate human impact on biodiversity in a South African ecosystem.
• Suggest solutions to reduce human impact at a local level.

Lesson summary

Environmental studies and understanding human impact are crucial for all South Africans. Our rich biodiversity, from the fynbos of the Western Cape to the savanna of Kruger National Park, is under increasing pressure from human activities. This week, we will explore how our actions, both big and small, affect the environment around us, focusing specifically on pollution, resource depletion, and habitat destruction. Recognizing these impacts is the first step toward finding sustainable solutions and preserving our natural heritage for future generations.

Lesson notes

2.1 Introduction to Environmental Impact Human activities are the primary drivers of environmental change. These activities release pollutants into the air and water, consume natural resources, and transform natural habitats into agricultural lands, urban areas, and industrial sites. Environmental impact refers to the effects of these activities on the environment. These impacts can be positive or negative, direct or indirect, and short-term or long-term. In general, the term is used to describe negative changes. 2.2 Pollution Pollution is the introduction of contaminants into the natural environment that causes instability, disorder, harm or discomfort to the ecosystem, i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat, or light.

The major kinds of pollution include: Air Pollution: Air pollution is caused by the release of harmful substances into the atmosphere. Common sources include vehicle emissions (exhaust fumes from cars, trucks, and buses), industrial processes (factories releasing smoke and chemicals), and burning of fossil fuels (coal-fired power plants). In South Africa, coal-fired power stations contribute significantly to air pollution in areas like Mpumalanga, impacting human health and the environment. The burning of wood and paraffin for heating and cooking in informal settlements is also a significant source of indoor and outdoor air pollution. Consequences include respiratory problems (asthma, bronchitis), acid rain, and global warming.

Example: High levels of particulate matter (PM2.5 and PM10) in the air in industrial areas like Secunda can cause severe respiratory illnesses, especially in children and the elderly.

Water Pollution: Water pollution occurs when harmful substances contaminate bodies of water, such as rivers, lakes, oceans, and groundwater. Sources include industrial discharge (factories releasing wastewater), agricultural runoff (fertilizers and pesticides washing into rivers), sewage (untreated or poorly treated wastewater), and mining activities (acid mine drainage). South Africa faces significant water pollution challenges due to mining, industrial activities, and inadequate sanitation infrastructure. The consequences of water pollution include the death of aquatic life, contamination of drinking water sources, and the spread of waterborne diseases.

Example: Acid mine drainage from abandoned gold and coal mines in Gauteng and Mpumalanga pollutes rivers and groundwater, making the water unsafe for human consumption and harming aquatic ecosystems.

Land Pollution: Land pollution results from the accumulation of solid and liquid waste on land. Sources include improper disposal of garbage (landfills, illegal dumping), industrial waste (chemicals, heavy metals), agricultural waste (pesticides, herbicides), and mining activities (mine tailings). Land pollution can contaminate soil and groundwater, harm plants and animals, and pose risks to human health.

Example: Plastic waste accumulates in landfills and pollutes natural environments, harming wildlife that ingest or become entangled in plastic debris. The improper disposal of electronic waste (e-waste) releases toxic chemicals into the soil. 2.3 Resource Depletion Resource depletion refers to the consumption of a resource faster than it is replenished. Natural resources like water, minerals, forests, and fossil fuels are finite, and overuse can lead to scarcity and environmental damage.

Water Depletion: South Africa is a water-stressed country, and overuse of water resources for agriculture, industry, and domestic use is leading to water scarcity in many regions. Droughts exacerbate the problem, leading to water restrictions and conflicts over water rights.

Example: Over-extraction of groundwater for irrigation in the Western Cape has led to the depletion of aquifers and increased competition for water resources during droughts.

Deforestation: The clearing of forests for agriculture, logging, and urban development is leading to deforestation, which results in habitat loss, soil erosion, and climate change.

Example: Illegal logging and clearing of indigenous forests in KwaZulu-Natal for timber and agriculture are contributing to habitat loss and biodiversity decline.

Mineral Depletion: The extraction of minerals like gold, platinum, and coal has significant environmental impacts, including habitat destruction, water pollution, and air pollution. The depletion of these resources raises concerns about the long-term sustainability of the mining industry.

Example: The intensive mining of coal in Mpumalanga has led to the degradation of vast areas of land, water pollution, and air pollution, impacting local communities and ecosystems. 2.4 Habitat Destruction Habitat destruction is the process by which a natural habitat becomes incapable of supporting its native species.