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Overview
Overview
In this activity, you will examine the basic components of the Earth's soil, water, and air. You will learn about the different soil layers and be introduced to the importance of a clean, freshwater supply. Finally, you will learn about the composition of the Earth's atmosphere.
Content
Content
The Earth is an amazing planet with an environment capable of supporting life. Humans have substantially altered the Earth's environment. To understand human's impact on the environment, we must understand the Earth's basic components: soil, water, and air.
1. Soil
1. Soil
Soil is a mixture of minerals, organic matter, air and water and is essential for terrestrial plants and all life on land.
The Four Components of Soil
1. Mineral Material
Small particles of weathered rock form the basis of soil. The size of the particles determines the soil texture (see below).
2. Organic Matter
Organic matter, consisting of decomposing animal and plant material, provides nutrients for soil. The second organic component of soil is the actual organism community itself. These include millions of bacteria in each teaspoon of soil, earth worms, insects and moles, which actively mix, fertilize with excreta, and modify all the components of soil.
3. Air
Air supplies oxygen and dissolved nutrients for soil organisms.
4. Water
Water is essential for soil organisms to survive. It also transports mineral and organic material throughout the soil.
Soil Texture:
Soil texture is determined by the size of the mineral (rock) particles in the soil. Sands are the coarsest (largest particles) soils, Silts are the medium coarsest, and clays are the finest (smallest particles) soils.
Course textured, sandy soils drain quickly, and do not hold water well, whereas fine, clay soils have poor drainage and hold more water and nutrients.
A soil triangle is used to determine the classification of soil based on the percentage of sand, silt, and clay found in the soil.
Soil Triangle for identifying soil type
Soil Layers:
If you dig down deep enough into soil, you will notice that it has different layers, called horizons. These layers contain different amounts of organic and mineral matter. The climate, and type of vegetation, affects the depth of the different layers of soil. Deserts have a very thin layer of topsoil due to lack of rain, and minimal plant growth compared to grasslands covered in vegetation.
CHECK YOUR UNDERSTANDING OF SOIL
Which type of soil, sandy or clay-based would hold more water? Explain why.
Explain the difference between leaf litter and humus.
How does humus get down into the subsoil from near the surface of the ground?
2. Water
2. Water
You can drink it, wash in it, play in it, and make things with it.
All living things need water. The human body is over 65% water. We can go for over a month without food, but can only live a few days without water.
Water, H2O, is a substance consisting of two hydrogen atoms attached to one oxygen atom. It is clear, colourless, tasteless, and has no odour. It freezes at 0°C, and boils at 100°C.
In nature, water is not 100% pure. It contains various naturally occurring dissolved substances, such as calcium, iron, and other minerals. Unfortunately today, our water also contains a variety of human-made chemicals and other pollutants.
Water Use
Canadians use an average of 329 litres of water per person per day, the second most per person in the world, behind the United States. If the average Canadian uses 329 litres of water in a day, imagine how much water we use in a year. Let's take a look:
The average Canadian uses 329 litres of water/day, and there are 365 days in a year.
329 litres/day X 365 days/year = 120 085 litres
So the average Canadian uses 120 085 litres of water in 1 year.
The average life expectancy for a Canadian female is 80 years. If she uses about 120 000 in 1 year, how much water will the average Canadian female use in her lifetime?
120 000 litres/year X 80 years = 9 600 000 litres
So the average Canadian woman will use about 9 600 000 litres of water in her lifetime.
Watch the Video about Water Supply and Consumption
Water Distribution
About 70% of the Earth's surface is covered in water. However, most of the water is unsuitable for many human uses. Over 97% of the world's water supply is salty ocean water, and another 2% is trapped, frozen in glaciers. This leaves less than 1% of the world's water available for human use.
Canada has 7% of the world's renewable freshwater supply, but 60% of our water flows north to the arctic, while over 80% of our population live in the south near the Canada/US border. Increasing pollution of our surface and groundwater further reduces our supply of readily available, clean water.
CHECK YOUR UNDERSTANDING OF WATER
If the average Canadian uses about 120 000 litres of water in one year. How much water would a family of four use in one year?
1316 litres
120 000 litres
480 000 litres
30 000 litres
240 000 litres
Even though Canada has thousands of lakes, we need to protect our fresh water supply because:
growing water demand decreases our water quality because of pollution.
other countries might want to buy our water.
most Canadians live in the southern part of Canada, but 60% of our water flows to the north.
most of our freshwater is frozen in the wintertime.
both a) and c).
Most of the world' water supply is unsuitable for many human uses, such as drinking because:
the water is too polluted
the water is frozen in glaciers.
the water is salty, ocean water.
the water contains naturally occurring minerals, such as calcium and iron.
both b) and d).
3. Air
3. Air
The Earth is surrounded by a blanket of air, called the atmosphere. The atmosphere provides us with the oxygen we breathe, it helps regulate the Earth's temperature and protects us from harmful ultraviolet radiation from the sun.
The atmosphere consists of a mixture of gases, mainly nitrogen (78%), and oxygen (21%), and small amounts of several hundred other gases, held close to the Earth's surface by the force of gravity.
Carbon dioxide helps to trap heat near the Earth's surface making the climate warm enough to support life. Too much carbon dioxide may contribute to the greenhouse effect and global warming.
Ozone consists of three oxygen atoms joined together. Ozone forms a layer 20 to 30 kilometres above the Earth's surface. This layer absorbs most of the ultraviolet radiation coming from the sun, which can be harmful to living things.
Composition of Earth's Atmosphere
Layers of the Atmosphere:
Scientists have identified several distinct layers in the atmosphere with different temperatures, density and chemical composition. Atmosphere consists of five layers
1.Troposphere
2.Stratosphere
3.Mesosphere
4.Ionosphere or thermosphere
5.Magnetosphere or exosphere
The troposphere is the most important layer since it supports life and is responsible for the climate and weather we experience.
Class Work:
Class Work:
Complete the following work in google classroom
1. Activity 1a - That's a Lot of Water!
As you have discovered, Canadians on average use 329 litres of water a day every day. Answer the following questions and submit in google classroom. You must show your work for mathematical calculations.
Based on an average life expectancy of 75 years, how much water will the average Canadian male use in his lifetime?
Using the Canadian average of 329 litres per person per day, how much water does your family use in one year?
If the average backyard swimming pool holds 150 000 litres of water, how many swimming pools of water will you use in your lifetime?
List five simple things you can do at home to reduce the amount of water you use.
2. Activity 1b - Layers of the Atmosphere
Research the layers of the atmosphere and fill in the Layers of the Atmosphere Chart found in google classroom.
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