NOTE:
This presentation was not made for public use. Please do not use this presentation without my permission and the permission of each of the authors of the photographs, quotes, and other materials that they contain.
Thank you,
Vicki Hughes
Labs, Activities, and WS for this presentation: none

EARTH’S WATER (EOG L21)
75% of Earth

•
pH Lab

• A water molecule is
.

15.1
hydrogen bonds hold water molecules together

Surface Tension = Tendency to avoid separating of molecules on the surface
– Due to hydrogen bonding
– Cohesion – water’s attraction to other water
Water on a Penny

• Cold water contracts and its density increases.
• Below 4˚C, the density of water starts to decrease .
• Frozen water is less dense than cold water.

• Density allows ice to float in cold water.

Ice is an open framework of water molecules arranged like a honeycomb .

Air temperatures are warm.
Water at the surface is warm.
Deep water is cool.
– When ice melts, the framework collapses, and the water molecules pack closer together, making liquid water more dense than ice.

Air temperatures are cooling.
Water at the surface cools to 4 o C and sinks because it is more dense.
4 o C

Air temperatures are cold.
Water at the surface freezes and expands causing it to float.
4 o C

High Specific Heat – takes a lot of energy to change the temperature
Ahhh…
Brrr!
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Structure of the Hydrosphere
•
(80% on EOG)
Salt Water
Nonpotable
• Potable = drinkable
Nonpotable = not drinkable

Structure of the Hydrosphere
•
Potable
• Of all the freshwater in the world about 75% is frozen and unavailable to drink without alteration

Structure of the Hydrosphere
• Groundwater is most of the remaining freshwater.
• Groundwater is the water that exists in large cavernous layers from which we usually drink .
• When droughts occur groundwater becomes too low.

Structure of the Hydrosphere
• The remaining 0.02% of all water on Earth makes up our lakes, rivers, ponds, atmosphere, and soil water.
• Soil water is water that is held within the tiny spaces in the soil.

Headwaters = all of the streams that combine to make a larger stream.
Delta = deposited soil from a river that build up until it rises above the water.
Base level = lowest point to which a stream can erode its channel .

Tributary = a stream or river that empties into another stream or river .
tributaries
Rutherfordton
Broad River

WATERSHEDS = the areas of land in which all rain that falls contributes to the same stream .
All major watersheds drain to the ocean.
Flash: Rivers Shapers of Earth
OCEAN

RIVER BASIN = the area of land in which all rain that falls flows into a large river .
Broad River
Flash: Rivers Shapers of Earth

• Fact: The ground you walk on is not solid!
• Fact: There are countless tiny pore spaces between grains of soil.
• Fact: The spaces fill with water.
• Fact: The water in the spaces collects and moves.

When rain falls…
…some of the water runs off ,
…some of the water evaporates ,
…and the rest soaks into the ground .
How much water soaks into the ground depends on…
…steepness of slopes,
…natures of surface materials,
…intensity of the rainfall
…type and amount of vegetation.

Zone of Aeration = area where soil is not saturated with water.
Water Table = upper limit of the zone of saturation

Zone of Saturation = area where water fills all open spaces in sediment and rock (GROUNDWATER)
GROUNDWATER

Subsurface Material:
• Porosity = % of ground consisting of pore spaces .
Can still block the movement of water underground.

• Permeability = allows fluid to travel through
• Groundwater moves by twisting and turning through pores that are connected.

Aquifer = permeable rock that allows the movement of underground water .
Aquitard = impermeable layers that prevent the movement of underground water.
AQUIFER

Groundwater moves more slowly when pore spaces are smaller.
Goes through too fast!
Goes through too slow!
Goes through just right.

Groundwater is NOT renewable!
• 65% used for crop irrigation
• When groundwater is removed faster than it can be replenished ground may sink as water is removed.
India

WATER POLLUTION (EOG L24)
Point-Source Pollution = comes from one specific source .
Easier to identify, so easier to control .
Dishwater from homes
Factories
Damaged Wastewater pipes https://www.youtube.com/watch?v=phmN-IpR3xw

SOURCES OF WATER POLLUTION
NONPoint-Source Pollution = comes from several sources .
Difficult to identify, so difficult to control .
https://www.youtube.com/watch?v=HDxNy65pSOE

WATER QUALITY (EOG L25)
There’s been a death at Hughes’ Pond! Did Wild Willie die from drinking unhealthy pond water or was he
MURDERED! Let’s look at the suspects!
C. E. Owe Bathing Bertha
Speedy Sam
Professor Acid R. Base
Farmer John
Mr. Bubbles
HUGHES POND

Meet Detective Bob.
Bob’s Mission: Determine if
Wild Willie’s death was the result of drinking unhealthy pond water or a MURDER!
HUGHES POND

of the pond. Bob knows that the temperature must be cool for the pond to be healthy.
Cool water can hold more oxygen than warm water.
More oxygen means healthier water. Hot water will also indicate that
Bathing Bertha killed Willie!
Good! The water is cool.
HUGHES POND

pH : Next Bob must examine the pH of the pond. Bob knows that pH measures the acid or base .
The pH should be neutral . Neutral is 7.0 on the pH scale. Anything higher or lower would indicate an unhealthy pond … and Professor Acid R. Base!
Perfect!
We appear to have a nice pH of
7.0.
HUGHES POND

Dissolved Oxygen: Next Bob must examine how much oxygen is dissolved in the water of the pond. Bob knows that the pond must have adequate dissolved oxygen to be healthy .
High
Low water temperature should mean we have high dissolved oxygen content.
Mr. Bubbles could have
Oxygen content.
Excellent!
sucked all the dissolved oxygen out AND murdered
Wild Willie!
HUGHES POND

Turbidity: Now Bob must examine the turbidity ( clarity ) of the pond. Bob knows that high turbidity is very unhealthy .
I see a bit of algae which can cause high turbidity…
Or Speedy
Sam could have stirred up the pond!
But it doesn’t appear to be an ALGAL BLOOM (fast growth of algae) so I think we’re ok.
HUGHES POND

Nitrates = nitrogen compounds that plants use for growth.
If we have too many nitrates in the pond, the pond will become overcome with pond scum and other unwanted plant life. Farmer John always carries fertilizer in his pockets. He could have killed Willie and dropped some in he pond!
John. The nitrates are normal!

Organisms or parts of organisms that are sensitive to water health. Healthy trout and low levels of chlorophyll a are indicators of good health.
If I can sneak up on the trout in this pond I can see if it appears healthy or unhealthy. Maybe C.E.Owe killed
Willie to hide waste dumped from his factory!
Excellent!
There’s plenty of trout and they appear to be healthy and happy.
HUGHES POND

I’m pleased to report that I studied the physical indicators, the chemical indicators and the biological indicators and I must report that the pond appears to be healthy. That only leaves one suspect!

What kind of detective are you? Identify which of the following bodies of water are healthy.
Clues: pH = 5.0, high turbidity, low oxygen, high nitrates
Deductions = high temperature, algal blooms

Clues: pH = 7.3, low temperature, high chlorophyll a
!

Clues: low temperature, high dissolved oxygen, pH 7.0

Natural Levees = landform that parallels some streams .

Artificial Levees
Flood-Control Dam
Limited Development
Levee construction. New Orleans 1727
Oklahoma
Riverside forests help to suppress overflowing water during floods

What happens when Flood Controls fail?
http://www.nola.com/katrina/graphics/credits.swf

Katrina + Poor Levees = Fatal Failure
Some of the following photos are graphic.

Sinkhole = depression produced in a region where groundwater has removed soluble rock.
Venezuela
Guatamala City
In Soviet Russia, the ground moves you.
Berezniki’s sinkhole began in 1986 and just sI grows worse with each passing year.
How Sinkholes form:
The vast Qattara west of Cairo, Egypt is the http://www.youtube.com/watch?v=nGkDouBV largest natural sinkhole in the world, oLs measuring 80km long by 120km wide.