Natural Resources & Conservation in South Africa PDF

TOPIC 4 NATURAL RESOURCES & CONSERVATION IN SOUTH AFRICA SUB-TOPIC 1 NATURAL RESOURCES 1. Water The water cycle is continuous and has no exact “starting” point; however, let’s “start” with oceans, where most...

TOPIC 4 NATURAL RESOURCES & CONSERVATION IN SOUTH AFRICA SUB-TOPIC 1 NATURAL RESOURCES 1. Water The water cycle is continuous and has no exact “starting” point; however, let’s “start” with oceans, where most of Earth’s water exists. The sun drives the water cycle. The water evaporates and becomes water vapour in the atmosphere. Water also evaporates from plants (transpiration), becoming water vapour in the atmosphere. The water vapour rises and eventually cools and condenses as clouds. Clouds hold water vapour until it becomes too heavy and drops back down in many forms of precipitation, the most common being rain. The following image shows the water cycle.  Most precipitation falls back into the oceans or onto land, where, due to gravity, it flows over the ground as surface runoff. Some of this surface runoff flows into rivers and valleys, but most precipitation seeps through the Earth's surface and becomes groundwater. Runoff and groundwater accumulate and are stored as freshwater in lakes. Not all runoff flows into rivers; a lot soaks into the ground. Some water infiltrates deep into the ground and replenishes aquifers (saturated subsurface rock), which store huge amounts of freshwater for long periods of time. Over time, all of this water keeps moving, some to re-enter the ocean. All living things need water to live. You can live for several weeks without food, but you will die in a few days if you do not have water to drink. Water is a valuable natural resource, as we use it for many different things. However, people often waste and pollute water. 2. Air Without air, there would be no life on Earth. We need air to stay alive. We (humans & other living organisms) inhale oxygen and exhale carbon dioxide, both of which can be found in the air. Machines that have engines also need oxygen. 3. Soil Soil is the layer on the surface of the land where plants grow. It comprises particles of rock, decaying animals and plants, water, air. Soil is an important natural resource; without soil, there would be no life on land. Plants grow in soil and provide animal food through a series of feeding levels called a food chain; without soil, there would be no animal food. 4. Forests A forest is an area with many trees and plants growing in it. The trees and plants grow in soil and need water and air to grow. People use wood from trees to build homes, make furniture and paper, and burn firewood. Some forests grow naturally, and people plant others; we call these forests plantations. People plant plantations so that they can have enough wood. 5. Animals and Marine life Animals and marine life are important natural resources. They are a source of food for other animals and humans. We get meat from animals as well as eggs and milk. Animal food is high in protein. Protein builds, maintains, and makes new tissues in your body. Animals may also help people do work, such as pulling machines on farms.