Importance of Water for Life

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Questions and Answers

Why is water considered essential for life on Earth?

It is abundant in nature.

It is easily available in rivers.

It is the primary source of energy.

It comprises 60–70 percent of the human body. (correct)

What percentage of the world's freshwater is accessible for human consumption?

0.3% (correct)

What is the primary use of the largest percentage of water withdrawn for human use in the US?

Thermoelectric power generation (correct)

Industrial manufacturing

Agriculture

Residential use

Which of the following is not one of the major water storage locations on Earth?

Atmosphere Signup and view all the answers

How does a river typically form?

From rainfall that becomes runoff. Signup and view all the answers

What factor does not affect the amount of time water stays in a given pool?

Weather conditions Signup and view all the answers

Which statement regarding surface and groundwater is accurate?

Many countries depend more on groundwater due to limited surface water. Signup and view all the answers

What is the term used for the smaller streams that join to form larger rivers?

Tributaries Signup and view all the answers

How much of the Earth's lakes and rivers contribute to the US's water supply for various uses?

70% Signup and view all the answers

What negative impact can the construction of dams have on aquatic life?

Prevent fish migration Signup and view all the answers

Which type of wetland is characterized by standing water and saturated soils?

Swamp Signup and view all the answers

What major human activity has significantly contributed to ocean pollution?

Overfishing Signup and view all the answers

Which river is considered the longest river in the United States?

Missouri River Signup and view all the answers

What percentage of the Earth’s water is stored in oceans?

95% Signup and view all the answers

What is a primary function of wetlands in ecosystems?

Support a wide variety of species Signup and view all the answers

Which of the following is NOT a benefit of constructing dams?

Enhancing fish migration Signup and view all the answers

What is the water table?

The top of the saturated zone Signup and view all the answers

Which of the following statements accurately describes the concept of infiltration?

It is the movement of water from the surface down to the saturated zone Signup and view all the answers

What leads to economic water scarcity?

Limited financial resources to build water infrastructure Signup and view all the answers

Which type of pollution is characterized by contamination from a single identifiable source?

Point source pollution Signup and view all the answers

What is one of the significant contributors to physical water pollution?

Excess sediment from poorly managed lands Signup and view all the answers

Which statement best describes biological pollution?

It consists of pollutants derived from living organisms Signup and view all the answers

What crucial factor contributes to water scarcity in arid regions?

High seasonality of rainfall Signup and view all the answers

How does Tony Allan's view on water distribution relate to affluence?

Wealthy countries have better access to safe drinking water Signup and view all the answers

What is a major consequence of water pollution on public health?

Spread of waterborne illnesses from pathogens Signup and view all the answers

Study Notes

Why is Water Important to Life?

Water is essential for life.
Water makes up 60-70% of the human body.
Water is a critical resource for human use and sustaining life on Earth.

How Much of Earth's Water is Available for Human Use?

Only about 3% of all water on Earth is fresh water.
Of the freshwater, only a tiny portion is available for human consumption.
Most freshwater is locked up in ice.
Most available fresh water is found underground as groundwater.
Only 0.3% of the world's freshwater is surface water in rivers, lakes, and swamps.

Water Storage Locations on Earth

The major locations of water storage on Earth are oceans, glaciers, groundwater, rivers, and lakes.
Water spends different amounts of time in each storage location depending on the volume of water and the speed of water movement.
The water cycle is a continuous global cycling of water from one pool to another.

Streams and Rivers

Rivers form from water moving from a higher altitude to a lower altitude, under the force of gravity.
When rain falls on land it either evaporates, seeps into the ground, or becomes runoff.
Runoff can concentrate into channels called creeks, streams, or rivers.
Smaller streams and creeks join together to form larger rivers. These smaller streams and creeks are called tributaries.
The land area drained by a river and all its tributaries is called a watershed.
The Mississippi River is the largest river in the US by volume.
The Missouri River is the longest river in the US.
Most of the rivers in the world are too polluted to support swimming, fishing, and drinking.

Lakes, Reservoirs, and Ponds

A body of standing water on the land surface is called a lake, pond, or reservoir.
Reservoirs are artificial lakes that are formed when dams are built to stop rivers from flowing.
Canada has about 60% of the world's lakes.
The US gets two-thirds of its water from lakes and reservoirs.
Dams have benefits and negative impacts on people and the environment.
Benefits of dams include providing a source of water, recreational opportunities, and reducing local flooding.
Impacts of dams include increased severe flooding downstream, trapping stream sediments, disrupting and damaging aquatic habitats, preventing aquatic organisms from migrating, and displacement of local people.

Wetlands

Wetlands are areas that have standing water, saturated soils, and plants that require large amounts of water to survive.
Wetlands provide a great deal of food that supports a wide variety of species.

Oceans

Oceans store the majority of all water on Earth (about 95%).
Oceans are an important part of the hydrologic cycle, with high biological diversity and many landforms.
Human activities such as pollution, overfishing, carbon dioxide acidification, and global warming are degrading oceans.

Groundwater

Groundwater is found below the surface of the Earth in porous rock layers.
Water seeps into the ground, through unsaturated rocks or sediments, to become groundwater.
The top of the saturated portion is called the water table.
Aquifers are bodies of rock or sediment that store large amounts of usable water in their pores.
Groundwater is a renewable resource but can become nonrenewable if water is removed faster than it can be replenished.

Water Scarcity

Water scarcity is a major environmental crisis facing the world today.
Over one billion people in the world lack access to clean drinking water.
The demand for water has grown rapidly due to global population growth.
There is enough fresh water on Earth to provide every human with enough drinking water, but it is unevenly distributed, polluted, mismanaged, and wasted.
Water scarcity is caused by demand for water being greater than the supply.
Scarcity can be physical or economic.
Physical scarcity is an actual shortage of water, regardless of quality or infrastructure.
Economic scarcity is a lack of financial resources and/or infrastructure to supply safe drinking water.

Water Pollution

Water pollution is a major problem facing many of our surface water and groundwater sources.
Contamination can be natural or anthropogenic (caused by humans).
Human sources of pollution can be categorized as either point sources or non-point sources.
Point source pollution comes from a single point.
Non-point source pollution is discharged over a wide land area.

Types and Sources of Water Pollution

Contamination of water resources can be physical, biological, or chemical.

Physical Pollution

Excess sediment in runoff from agricultural plots, clear-cut forests, poorly managed lands, and plastic refuse products are physical pollutants.
Temperature changes from power plants and industrial facilities are also a form of physical pollution.

Biological Pollution

Biological pollution refers to pathogenic microorganisms and organic wastes that come from living organisms.
Pathogenic microorganisms include bacteria, viruses, and protozoa that cause diseases in humans.
Organic wastes include animal waste and plant debris.

Chemical Pollution

Chemical pollution includes heavy metals, pesticides, herbicides, and fertilizers.
Mining operations are a major source of heavy metals.
Improper storage and use of automotive fluids can cause water pollution.

Eutrophication

High concentrations of nitrogen and phosphorus in water can lead to eutrophication, which is an excess of nutrients in a body of water that leads to the overgrowth of algae and aquatic plants.

Water Management

Pollution control begins with testing and monitoring of water quality.
Nonpoint source control relates to land management practices in agriculture, urban design, and sanitation.
Good urban planning and design can reduce stormwater runoff.
Using native plants and xeriscape techniques reduces water use and minimizes the need for pesticides and fertilizers.

Clean Water Act (CWA)

The CWA is the primary federal law governing water pollution.
The goals of the CWA are to eliminate pollutant discharge and increase the amount of fishable and swimmable waters in the US.
The act covers point and nonpoint sources.
The EPA works with federal, state, and tribal partners to monitor and ensure compliance with water quality laws and regulations.
The CWA is a partnership between states and the federal government.
The federal government sets standards and states carry out the implementation of the law.
States can set standards more stringent than the federal standards.
Under the CWA, discharge into US waters is only legal with a permit.
The CWA helped make burning rivers a thing of the past in the US.

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Description

This quiz explores the vital role water plays in sustaining life on Earth. It covers topics such as the composition of the human body, the availability of freshwater, and various water storage locations. Test your understanding of the water cycle and the significance of freshwater resources.