Water Resources

Chapter 11 Section 1

What do we use water for?

Where does our water come from?

Did you know?Humans can survive for more than a month without food, but we can live only a few days without water.

Two Kinds of WaterFreshwater

Water that people can drink

Contains little salt

Used for drinking and agriculture

Saltwater

Water found in oceans

Contains a higher concentration of dissolved salts

The Water PlanetWater is a renewable resource because it is circulated in the water cycle.Water molecules travel between the Earth’s surface and the atmosphere.Water evaporates and leaves behind salts and impurities.

The Water Cycle

The Water CycleWater vapor rises into the air.As water vapor rises through the atmosphere, the gas cools and condenses into drops of liquid water to form clouds.Eventually the water in clouds falls back to Earth and replenishes the Earth’s fresh water.

Global Water Distribution

71% of Earth’s surface is covered in water.

97% is salt water3% is freshwater

77% of the freshwater is frozen is glaciers and polar ice caps.

Surface WaterFresh water on Earth’s land surface.Found in lakes, rivers, streams, and wetlands.Vital role in the development of human societies.

River SystemsStreams form as water from falling rain and melting snow drains from mountains, hills, plateaus, and plains.Streams combine and form rivers.As streams and rivers move across the land, they form a flowing network called a river system.

WatershedsThe Mississippi, the Amazon, and the Nile are enormous river systems because they collect the water that flows from vast areas of land.The area of land that is drained by a river is known as a watershed.Pollution anywhere in a watershed may end up polluting a river.

WatershedThe amount of water that enters a watershed varies throughout the year.

Rapidly melting snow as well as spring and summer rains can dramatically increase the amount of water.

How can communities around a watershed be affected by severe changes?

FloodsDroughtsDepend on water

WatershedsMissi

WatershedsMississippi is largest in the United States

WatershedsThere are 14 watersheds in

New Jersey.Closest to us is the Raritan

Watershed.

GroundwaterMost freshwater available for humans is underground.Water stored beneath the Earth’s surface in sediment and rock formations is called groundwater.As water travels beneath the Earth’s surface, it eventually reaches a level where the rocks and soil are saturated with water – known as the water table.

GroundwaterAn underground formation that contains groundwater is called an aquifer.

Holds water like a sponge.Porosity is the amount of space between the particles that make up a rock. Water is stored in these space.The ability of rock or soil to allow water to flow though is called permeability.

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

It cannot reach an aquifer from places where the aquifer is covered by impermeable materials.

Why is freshwater considered a limited resource?

Write down one thing that you learned, and one question that you still have.