Earth Science Home

 

Animations worth looking at:

Groundwater and Hydrogeology  
18.swf Artesian Well and Confined Aquifer Figure 11.9
19a.swf Cone of depression 1 Figure 11.18
19b.swf Cone of depression 2: upgradient flow Figure 11.18
19c.swf Cone of depression 3: saline intrusion Figure 11.18
20.swf Geyser Eruption Figure 11.27
Other Resource Links: Earth Science Animations: Groundwater Animations Links
  1. LINK GROUNDWATER SPEED
    DESCRIPTION Michigan Tech University, most have little idea on how slow groundwater can move. For this Flash animation, water movement is contrasted for three different environments: river, lake, and aquifer. Whereas the movement of water in a river is depicted as 7 ft/s, movement in an aquifer is only .33 ft/day.

  2. LINK PERMEABILITY
    DESCRIPTION Michigan Tech University, in this Flash animation the permeabilities of four different substrates, gravel, sand, silt, and clay are contrasted. Permeability is the ability to transmit liquid. In this animation substrate permeability range from two minutes for a meter of gravel to two hundred years for clay.

  3. LINK CONE OF DEPRESSION
    DESCRIPTION McGraw Hill, a simple Flash animation exhibits the formation of a cone of depression as a result of groundwater overdraft. Contaminants from a nearby landfill are drawn into the cone of depression. At this same page, there are a number of other groundwater animations, including salt water intrusion and the formation of an artesian well. Access the animation by clicking on the `Pumping Well and Cone of Depression` link.

  4. LINK GEYSER ERUPTION
    DESCRIPTION Exploring Earth, the Flash animation uses a cross section to explain geyser eruption. As groundwater enters fractured bedrock, it is heated by nearby magma but is prevented from boiling by the pressure of overlying water. Eventually, the water becomes superheated and is forced upward, pushing water to the surface. The animation can be paused and rewound to emphasize important points

  5. LINK HYDROLOGIC CYCLE AND GROUNDWATER
    DESCRIPTION Wiley, a QuickTime animation with accompanying audio outlines the basic pathways associated with the hydrologic cycle. The second part of the video focuses on groundwater, discussing such terms as infiltration, percolation, and groundwater table. Contamination issues are also introduced. The idealized flow lines shown in cross section should be viewed with caution, especially for limestone and glacial terrains where groundwater flow can be much more circuitous. The animation loads slowly.

 

 

 

1. Mr. Gessler's Web page on Recharge Basins " I love to swim in these things!"

 

2. PDF version of Gessler's web page

 

3. The Long Island Water Cycle

 

4. How much water do I use?

 

5. Smithtown (zone 12) water quality report

 

6.How the land was formed (LI)

Ancient, Clean, Controversial

 

7. In the belly of the earth

8. Lake Ronkonkoma Myths legends

 

9. Saltwater intrusions

 

10. Great Well Pumping Simulation*************

 

11. Simulated water flow through rocks*************

 

12. Porosity & permeability

 

13. A Civil Action (movie related to GW pollution) true (IMPORTANT:Who runs this web page?)

 

14. Erin Brockovitch (movie related to GW pollution) true

 

15. The Water Cycle another website

 

16. Freshwater on earth

 

17.More LI Hydrology

 

18. Citizens Environmental Research Institute- good info on Long Island resources

 

19. GW Contamination

 

  1. WATER TOWERS

  2. NYC Water tunnels

  3. NYC Catskill reservoirs

  4. Dont' Drink the Water-Cryptosporidium and Giardia Background Information

  5. WHICH IS LI'S MOST IMPORTANT AQUIFER? 3/2/04

  6. A sinkhole caused by groundwater

 

 

 

 

Hydrology 121- Long Islands Groundwater story by Professor Bennington of Hofstra University

Name_________________ Earth Science Lab: What is Groundwater?

Questions :

  1. Where does groundwater come from originally?
  2. In porous surface material that water readily seeps through, such as sand or gravel ____________% of rain or snow may seep into the ground.
  3. This means approximately ______% evaporates back into the atmosphere as water vapor.
  4. The force that pulls water into the saturated zone is called_____________.
  5. Water is contained by soils in the openings called____________.
  6. The top of the saturated zone is called the _________________.
  7. Above the saturated zone the soil pore spaces contain air. This zone is called the _________________.
  8. The water table rises and falls according to the ___________ and amount of __________.
  9. Define permeability completely:
  10. Explain what impermeable means:
  11. What is an aquifer?
  12. What type of soil will yield a large mount of water?__________________
  13. Water seeping into an aquifer is called___________________
  14. Groundwater that is confined under pressure is called a ______________ aquifer.
  15. The maximum level water will rise in an artesian well is the ______________surface.
  16. Aquifers not confined under pressure are called_______________ aquifers.
  17. Groundwater leaves the ground at _____________ points.
  18. Groundwater flows from areas of ______________ to ____________ points.
  19. Streams that receive groundwater discharge are ______________ streams.
  20. Streams that lose water to the water table are called______________ streams.
  21. When water is pumped from a well the water table is depressed. This is called the __________________________.
  22. If the groundwater is pumped too much what can happen to the water table with respect to the bottom of the well?
  23. What is the truth about "vast underground rivers?"
  24. What is the relationship between streams, lakes and groundwater?

What stops groundwater from sinking past a certain depth?

 

 

 

3/3/03

The Long Island Aquifer System and time for the water to move from the water table to the various aquifers

 

  1. Long Island is a community of people that reside above a sole source aquifer system. This is our only source of fresh drinking water.

  2. The uppermost aquifer the Upper Glacial Aquifer has been severely polluted in many towns. Common sources of pollutants are from cesspools, automobile fluids, dry cleaners that illegally have dumped wastes and illegal dumping. Many people choose to illegally dispose of materials in wooded areas far from their homes. Often on hikes I have encountered debris from construction and from people doing oil changes on their cars. State law mandates that all registered automobile repair shops have to accept up to 5 gallons of used motor oil from you. they are legally responsible to have the oil removed by a private licensed oil recycler. this means that there is no reason to illegally dispose of used oil.

  3. The more we continue to develop, the less natural open space there will be to allow rainwater and precipitation to infiltrate into the groundwater supply we depend upon.

  4. Would you be surprised to learn that there was once a forest and Plains that ran from Brooklyn to Montauk? There is only a small remaining area today called the Long Island Pine Barrens. This forest is composed of extremely sandy soils that lack enough nutrients to support much more than Pitch pine trees and Scrub Oaks. The sandy soils are well drained and have high permeability's. It is here that our drinking water supplies are filtered by nature. any further destruction and development jeopardizes our drinking water.

  5. The Hempstead Plains and Oak Brush plains have been reduced to nearly nothing. The plains used to cover most of the south shore of long island. They have been reduced now to just 19 acres directly next to the Nassau Coliseum.

Below is a surface map indicating Long Islands Watersheds. The Pin Barrens watershed provides clean drinking water to the 1,438,973 people in Suffolk county( 1991 census estimate.)

Print and Color This Map!

 

 

 new notes: 2/27/04

 

 

The Water Cycle

 

 

Ø      Precipitation, Evaporation, Transpiration are all major points of the water cycle

Ø      The water cycle is powered by the energy from the sun.

 

Where is the Earths water found?

Water source

Water volume, in
cubic miles

Percent of
total water

Oceans

317,000,000

97.24%

Icecaps, Glaciers

7,000,000

2.14%

Ground water

2,000,000

0.61%

Fresh-water lakes

30,000

0.009%

Inland seas

25,000

0.008%

Soil moisture

16,000

0.005%

Atmosphere

3,100

0.001%

Rivers

300

0.0001%

Total water volume

326,000,000

100%

ü     Of the 3% of water that is “fresh,” we only can access 0.63 %

 

ü     Most of the world’s water is in the form of liquid ground water.

 

What happens to water that precipitates?

 

1.     The water can remain at the earth’s surface as ice or snow. It may also remain on the leaves of plants. This is called retention.

 

2.     The water may soak or Infiltrate and become stored in the ground as groundwater. Also called seepage or recharge.

 

3.     The water may flow over the land as runoff. Approximately 1/3  33 % of all precipitation will runoff due to gravity.

 

4.     The remaining 2/3 or 66% of precipitation will be evaporated or transpired back to the atmosphere.

 

Infiltration

Infiltration is affected by a few variables

1.     The lands slope

a.     steep slopes have more runoff than infiltration

2.     The degree of saturation

a.     when the soil is dry, more infiltration will occur because the pore spaces are full of air

b.     Below the water table soil is saturated

c.     Any water found in the saturate zone is called groundwater

 

Porosity

1.     Porosity is the percent of pore space in a material

2.     Generally, more porous materials have more infiltration

3.     Factors affecting porosity

a.     shape- the more spherical the particles the more porosity

b.     Packing- particles that are packed loosely have more porosity. If a soil is walked upon by animals or large vehicles travel over it, the soil becomes more densely packed reducing the porosity.

c.     Sorting- a well sorted soil has higher porosity

 

Permeability

1.     Permeability is the ability of a material to allow water or other liquids to pass through it.

2.     Permeability is a rate of flow. A change of distance during some time period.

3.     Permeability is affected by particle size- the larger the particle the higher the flow rate will be. 

4.     A material can be very porous but be impermeable if the pores are not connected.

5.     A material will have a low permeability if:

a.     the soil particles are cemented together

b.     the particles are very flat and have few connected pore spaces

c.     the ground is frozen and full of ice near the surface blocking water

 

Capillarity

1.     As water infiltrates the ground, some water is attracted to soil particles. Water molecules stick to surfaces and the attractive force is called capillarity.

2.     Capillary action is the upwards movement of water in soil

3.     Capillary action is greater when soil particle sizes is smaller

4.     As particle size decreases capillarity increases

 

Vegetation

1.     Grasses, trees and other plants can interact with falling precipitation. These plants absorb some of the falling waters KE reducing the force of impact preventing erosion.

2.     Plants allow water more time to infiltrate the ground by slowing the water.

3.     Areas with little plant material or plant litter have high amounts of runoff and more erosion.

 

Land Use

1.     People developing land completely disturb the natural flow of water in the water cycle.

2.     Most man made structures are impermeable. This prevents water from infiltrating and recharging groundwater supplies.

3.     Farm animals can compact soils, farms have high rates of erosion.

 

Stream Discharge

1.     Surface runoff occurs when:

Ø     The rate of precipitation exceeds the rate of infiltration

Ø     The pore space of loose material or rock is saturated

Ø     The slope is steep preventing infiltration

Ø     The water on the surface has not evaporated or sublimed

2.     Stream discharge- this is what water flowing in a stream is referred to as. It is a volume of water flowing past a certain point over some time.

3.     Units are Liters/minute, m3/second

4.     Generally after a storm a few hours later the runoff water causes the stream discharge to increase

5.     Stream discharge is typically highest in the spring when melting snow causes the water volume in a stream to increase and velocity to increase.

6.     FLOODING- occurs when the stream is overflowing its normal channel.

a.     Flooding occurs when Precipitation is much greater than infiltration rates and evapotranspiration is not great enough.

b.     Flooding can also be a result of a hurricane storm surge, coastal storm, Tsunami or extreme tides.

c.     The best plan of action is to move to higher ground, and have a planned escape route.