Water Resources

Water Resources

Middle School

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Learning Objectives

• Describe how geoscience processes lead to uneven distribution of fresh and salt water.

• Explain why fresh water is a limited, yet sometimes renewable, natural resource.

• Analyze the impacts of human activities like overuse and pollution on water availability.

• Identify essential resources from the ocean and the challenges to their sustainability.

Key Vocabulary

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Fresh Water

Water with low salt concentrations, which is essential for most terrestrial life on our planet.

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Groundwater

This is the water that is held underground within the soil or in rock crevices.

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Aquifer

An underground layer of permeable rock that can hold and transport a significant amount of groundwater.

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Geoscience Processes

These are the natural forces that actively shape the Earth, like erosion and tectonic movement.

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Water Scarcity

This refers to the lack of enough available fresh water resources to meet local demand.

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Desalination

A scientific process used to remove minerals and salts from saltwater to produce fresh water.

Key Vocabulary

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Overfishing

Removing a fish species from water at a rate it cannot replenish, leading to population decline.

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Replenishment

The process of restoring a resource, such as the natural regrowth of fish populations over time.

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A Planet of Salt Water

Earth's Water Supply

• The vast majority of the water found on our planet is salt water.

• About 97% of all water on Earth is salt water located in our oceans.

• This means that only a tiny 3% of the planet's water is fresh water.

Fresh Water's Limits

• A large portion of Earth’s fresh water is not easily accessible for our use.

• About 79% of this fresh water is frozen solid in ice caps and glaciers.

• Accessible fresh water is a limited resource that varies in availability across the globe.

Multiple Choice

Which statement accurately describes the distribution of water on Earth?

• Most of the water is salt water found in oceans.

• The water is evenly divided between fresh and salt water.

• Most of the water is fresh water stored in glaciers.

• All of the water on the planet is easily accessible.

Multiple Choice

Why is most of the Earth's fresh water not readily available for human use?

• It is all located deep underground.

• It is quickly evaporated by the sun.

• A large amount of it is frozen in ice caps and glaciers.

• It is too salty for humans to use.

Multiple Choice

Based on the provided information, what is the most logical conclusion about the supply of usable fresh water on Earth?

• It is found in equal amounts all over the world.

• It represents a very small percentage of Earth\'s total water.

• It is mainly stored in the Earth\'s oceans.

• It is greater than the total amount of salt water.

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Geoscience and Water Distribution

Surface Water

• Lakes form in depressions made by past glacial activity or the movement of tectonic plates.

• Rivers carve their own paths through the land using erosion, carrying water from high areas.

• These surface processes create visible places for fresh water to collect and flow.

Groundwater

• The amount of available groundwater depends on the geology deep below the Earth's surface.

• Water from rain and snow seeps through the ground into porous layers of rock.

• These water-filled rock layers are called aquifers, which store large amounts of groundwater.

Multiple Choice

What is the fundamental difference between surface water and groundwater?

• Their location, with one being on the surface and the other being underground.

• The types of animals that live in them.

• Whether the water is fresh or salty.

• The source of the water, with one coming from rain and the other from snow.

Multiple Choice

How does the geology below the Earth's surface contribute to the formation of groundwater?

• Porous rock layers soak up water from rain and snow, which is then stored in aquifers.

• Glacial activity carves out depressions in the rock for water to fill.

• Tectonic plate movement pushes underground water to the surface.

• Rivers erode rock to create underground storage spaces.

Multiple Choice

A region's geology consists of deep depressions created by ancient glaciers, but the bedrock deep underground is solid and non-porous. What is the most likely scenario for water availability in this area?

• The area would likely have significant surface water in lakes but very limited groundwater.

• The area would have abundant groundwater in aquifers but very few rivers.

• The area would have an equal amount of surface water and groundwater.

• The area would be extremely dry because non-porous rock prevents any water from collecting.

Replenishment of Water Resources

• Groundwater is a renewable resource refilled by the water cycle.

• This replenishment process is very slow, taking many years.

• Using water faster than it refills can deplete the source.

Multiple Choice

What makes groundwater a renewable resource?

• It is refilled over time by the water cycle.

• It is an unlimited resource that never runs out.

• It refills very quickly after being used.

• It is a man-made source of water.

Multiple Choice

Why can a renewable resource like groundwater be depleted?

• The replenishment process is very slow compared to the rate of use.

• The water cycle occasionally stops working.

• The resource is not actually renewable.

• The water becomes too polluted to use.

Multiple Choice

A city's population grows, and it begins to pump more water from its underground aquifer. What is the most likely long-term effect on the aquifer?

• The water level will drop because it is being used faster than it can be refilled.

• The water cycle will work faster to replace the extra water being used.

• The amount of water will remain the same regardless of how much is used.

• The water source will automatically expand to meet the new demand.

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Human Impact on Water Resources

Water Depletion

• Humans rely on water for agriculture, industry, and daily life, leading to overuse in many areas.

• Underground aquifers are being depleted faster than they can be naturally refilled, causing water shortages.

• Building dams changes a river's natural flow, which can harm the environment downstream.

Water Pollution

• Waste from farms, cities, and industries often ends up in rivers, lakes, and groundwater.

• This pollution contaminates the water, making it unsafe for people and animals to use.

• The combination of overuse and pollution leads to severe water scarcity in many regions.

Multiple Choice

Which statement best summarizes the primary ways humans impact water resources?

• By overusing and polluting available water

• By creating new underground water sources

• By only building dams on major rivers

• By increasing the natural refilling of aquifers

Multiple Choice

How do human actions like building dams and overusing aquifers impact the environment?

• They can change a river's flow and cause water shortages.

• They create more habitats for fish and refill aquifers.

• They only pollute the water but do not reduce it.

• They increase the amount of fresh water for downstream areas.

Multiple Choice

A farming community starts using large amounts of water from its river for irrigation, while a new factory releases waste into the same river. What is the most likely combined effect on the community's water?

• The water will become both limited in quantity and unsafe in quality.

• The river will have less water, but its quality will improve.

• The river will become polluted, but there will be more of it.

• The water supply will remain unchanged by these activities.

Human Impact on the Oceans

• The ocean provides valuable resources like food, minerals, and fuel.

• Overfishing and pollution harm marine life and ocean ecosystems.

• Desalination turns salt water into fresh water but is costly.

Multiple Choice

What is the primary role of the ocean as a resource for humans?

• It provides valuable resources like food, minerals, and fuel.

• It is only useful for transportation between continents.

• Its main purpose is to regulate global temperatures.

• It is primarily a place for recreational activities.

Multiple Choice

What is the relationship between human activities like overfishing and pollution and the ocean?

• They can harm marine life and damage ocean ecosystems.

• They generally lead to an increase in fish populations.

• They have no significant effect on the ocean environment.

• They help to clean and purify the ocean water.

Multiple Choice

A coastal community wants to use desalination to solve its water shortage. What is the most likely challenge they will face in implementing this solution?

• The process is expensive to implement and operate.

• It produces water that is still too salty to drink.

• It can only be performed during certain times of the year.

• The process uses up too much salt from the ocean.

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Common Misconceptions

Misconception	Correction
Earth has an endless supply of fresh water.	Fresh water is a very small and limited resource.
Groundwater and surface water are separate.	They are often connected and can flow into one another.
The ocean is too vast for humans to harm.	Human activities can severely damage entire ocean ecosystems.
Desalination is an easy and cheap way to get fresh water.	Desalination is currently expensive and requires a lot of energy.

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Summary

• Geoscience processes cause uneven water distribution, making most usable fresh water frozen.

• Groundwater is replenished slowly by the water cycle.

• Human activities like overuse and pollution are depleting water resources.

• Overfishing threatens ocean resources, while desalination offers a costly solution to scarcity.

Poll

On a scale of 1-4, how confident are you about the concepts covered in today's review?

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