Water Resources

Water Resources

Where does the water come from that you drink? Freshwater and saltwater are the two kinds of water found on Earth.

Objectives

• Describe the distribution of Earth's water resources.

• Explain why fresh water is one of Earth's limited resources.

• Describe the distribution of Earth's surface water.

• Describe the relationship between groundwater and surface water in a watershed.

The Water Cycle

• Exists in all three states of matter.

• Renewable resource.

• The water cycle is the continuous movement of water between Earth and its atmosphere.

Global Water Distribution

• Fresh water is a limited resource.

• 97.5% is saltwater.

• Most of the freshwater is tied up in ice caps and glaciers.

Surface Water

• It is fresh water on Earth's land surface.

• Found in lakes, rivers, streams, and wetlands.

• Provide drinking water, water to grow crops, food, power for industry, and a means of transportation.

River Systems

• As water drains it forms streams.

• Streams combine and form rivers.

• The more streams that run into a river, the larger the river becomes.

• The streams and rivers form a river system

There are many small rivers, streams, and creeks that feed into the larger rivers.

Watershed

• The area of land that is drained by a river.

• Pollution anywhere in the watershed could end up polluting the river.

Groundwater

• Water stored beneath the Earth's surface in sediment and rock formations.

• It eventually reaches the water table where the rocks and soil are saturated.

• This may be at the surface or hundreds of meters below the surface.

Aquifers

• An underground formation that contains groundwater.

• Most consist of rock, sand, and gravel with a lot of spaces for water to accumulate.

One of the largest known aquifers in the world.

Porosity and Permeability

• Porosity is the amount of space between the particles that make up a rock.

• The ability of rock or soil to allow water to flow through it is called its permeability.

• The most productive aquifers are usually formed from permeable materials.

Recharge Zone

• To reach an aquifer, surface water must travel down through permeable layers of rock and soil.

• The area of the Earth's surface where water percolates down into the aquifer is called the recharge zone.

• Environmentally sensitive.

Wells

• A hole that is dug or drilled to reach groundwater.

• Reliable source of water.

• Height of the water table changes seasonally.

• Can run dry if in extreme drought or supply is used faster than it can recharge.

Multiple Choice

Which one is not a way water travels through the water cycle?

• Precip, runoff, evaporate, condensate

• runoff, evaporation, condensation, precipitation

• Condensation, evaporation, runoff, Precipitation

• Transpiration, condensation, precipitation, infiltration

Multiple Choice

Water is a what type of resource?

• renewable resource

• continuous resource

• non-renewable resource

Multiple Choice

Why is fresh water a limited resource?

• It isn't because it is a renewable resource

• Only 2.5% is drinkable and is stored in icecaps, rivers, and lakes.

• 97% of water is in the oceans and too salty to drink.

Multiple Choice

What is it called when creeks and smaller rivers join together to make a larger river?

• River Systems

• Watershed

• Topography

• Groundwater

Multiple Choice

What is a watershed?

• Water in an area

• Land that water flows over and through

• Water that flows into a river or stream

• Water that is salty

Multiple Choice

What is the relationship between groundwater and surface water?

• Surface water is found in lakes directly above underground water sources.

• There is no relationship between surface and groundwater; they form independently.

• Groundwater filters through the soil to form surface water.

• Surface water percolates through the soil to form groundwater.