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2. Why is water important? Water shapes Earth’s surface and affects Earth’s weather and climates. Water needed for life. Living things are made up of water Water is a natural resource 2

3. There is lots of water, so what’s the problem? 97% of water on Earth is salty. 3% is freshwater. 2/3 of that freshwater is frozen as ice and snow. Humans need fresh, clean water to survive. Freshwater is becoming a natural resource that cannot be replaced at the same rate at which it is used. 3

4. Fall as precipitation or may melt from ice and snow. Freshwater is found as either surface water or ground water. Surface water – fresh and salt water above the ground. Ground water – found under the earth’s surface. Aquifer – a body of rock underground that can store a lot of water and allows water to flow through it easily. Permafrost – a frozen layer of soil. 4

5. Water pollution – when waste or other material is added to water so that it is harmful to organisms that use it or live in it. 2 Types – 1. Point-source pollution – waste from one specific site. A major chemical spill or oil spill. A manufacturing plant. Can be controlled once the source is found. – 2. Nonpoint-source pollution – comes from many small sources and is more difficult to control. Sources include runoff from city streets, roads and drains, farms and mines. 5

6. Thermal Pollution – any heating of natural water that results from human activity. – Water that is used for cooling power plants gets warmed up. – Warm water has less oxygen available for organisms that live in the water. Chemical pollution – occurs when harmful chemicals are added to water supplies. – Chemicals used in agriculture; such as pesticides, herbicides and fertilizers (dissolved nutrients). – Industry such as factories produce toxic wastes. – Acid rain – forms when gases formed by burning fossil fuels mix with water in the air. Makes both water and soil more acidic Can harm both plants and animals 6

7. Biological Pollution – microbes (small organisms) in the water that can cause diseases such as dysentery (diarrhea), typhoid fever (bacteria in food) and cholera (intestinal disease). Eutrophication – An increase in the amount of nutrients in water from decomposing organisms. – Occurs naturally in water. – Human activity increases nutrients in the water from fertilizer runoff. 7

8. Measurements of water quality include testing the levels of: – dissolved oxygen (oxygen gas in water) – pH (how acidic or basic) – temperature (how hot or cold) – dissolved solids (harmful chemicals or calcium build-up) – the number and type of microbes (small organisms) in the water. – turbidity (cloudiness or clarity of water) 8

9. Water enters sewage systems where pipes carry it to wastewater treatment plants. Screens are used to remove large debris. Chemicals are added to remove harmful bacteria and other microbes. – Chlorine kills bacteria – Fluoride is added to help prevent tooth decay. Air is bubbled through the water to increase oxygen and cleanliness. Potable – water that is suitable to drink. 9

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13. Why is land important? Land supplies a solid surface for buildings and roads. The soil provides nutrients for plants and hiding places for animals. Minerals below the surface can be used for construction materials. Fossil fuels found underground; burned for energy. 13

14. 1. Recreational – we use natural areas/wild places -Include forests, grasslands, and dessert areas. -Used for hiking, bird-watching, biking, hunting, other fun activities. 2. Transportation – consists of roads and train tracks. -Roads in the U.S. highway system cover 4 million miles of land. -Trucks transport goods. -Smaller vehicles carry passengers. -Railroads carry freight and passengers. 14

15. 3.Agricultural – used to grow crops and raise livestock. 4.Residential – where we live. -Urban = cities and towns -Have large numbers of people and small areas of open land. -Rural = open land -Have low numbers of people and large areas of open land. -Urbanization – the growth of urban areas caused by people moving into cities. 5.Commercial and Industrial – small and large businesses take over by replacing rural areas. 15

16. Soil is a mixture of minerals, organic material, water and air. Soil forms when rocks break down and dead organisms decay. 1.It provides a habitat for organisms to live like insects and worms. -Decomposers (fungi and bacteria) break down dead organisms releasing nutrients back into the soil 2.It stores water and nutrients for Plants. - Plants are the base of a food chain which is important for the chain to continue. 16

17. Human activities can have negative effects on land and soil. Land degradation – the process by which human activity and natural processes damage land to the point that it can longer support the local ecosystem. 1.Urban Sprawl – urbanization; cities taking over rural areas. 2.Erosion – the process by which wind, water, or gravity transports soil and sediment from one place to another. - clearing land for farming. - deforestation 17

18. 3.Nutrient Depletion and Land Pollution – Plants need the right balance of nutrients to grow. 4.Desertification – the process in which land becomes more desert like and unable to support life. - overgrazing from animals. 18

19. 5.Deforestation – the removal of trees and other vegetation from an area. - Logging for wood - Removing vegetation - Urbanization - Can lead to increased soil erosion 19