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Structures of the Hydrosphere Labs

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1 Structures of the Hydrosphere Labs
P. McAven 8th Grade Science Riverwood Middle School

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3 Think About It  Where does our drinking water come from? How does it get here? What are some ways people can enjoy the features of a watershed? What might happen if the boundary between two countries runs through one watershed?

4 Crumple a Watershed Activity
What is a watershed? Watersheds are constantly in the news. They are arguably THE defining environmental and political issue across much of America, and will be throughout your lifetime. The current working definition of a watershed is: an area of land from which all the rain flows to a specific river, lake, or underground aquifer. The key point here is that a watershed is an area of land around a river or lake. It is not the river or lake itself. By definition, every piece of land on Earth is in a watershed (all rain goes somewhere).

5 Create Your Watershed On a blank sheet of paper, create your watershed by drawing some simple shapes to represent each item: Houses Farms Gas Stations Factories Other Now, place a piece of tape in one section of your paper to represent a parking lot.

6 Complete Your Watershed
Crumple and unfold your paper. Do not completely flatten it. Now, take a blue marker and draw where you think a river and/or streams would flow. It will then rain (spray with squirt bottle). Observe what is happening: Where is the water flowing, how fast, what color is it?

7 Conclusion Questions 1. Define “watershed.” What are the major features of a watershed? 2. What soil type contributes to flooding in a watershed and why? What type of soil have you observed in our area? 3. Why are wetlands important? 4. What are the impacts of constructing buildings, roads, and parking lots (impervious surfaces) through which water cannot be absorbed into the ground? 5. What is the name of the watershed in which your school is located? 6. What effects do farms, homes, gas stations, and factories have on our watershed?

8 Porosity & permeability Lab
porosity – the amount of empty space in a rock or other earth substance; this empty space is known as pore space. Porosity is how much water a substance can hold. Porosity is usually stated as a percentage of the material’s total volume. permeability – is how well water flows through rock or other earth substance. Factors that affect permeability are how large the pores in the substance are and how well the particles fit together. Water flows between the spaces in the material. If the spaces are close together such as in clay based soils, the water will tend to cling to the material and not pass through it easily or quickly. If the spaces are large, such as in the gravel, the water passes through quickly.

9 There are two other terms that are used with water: percolation and infiltration.
percolation – the downward movement of water from the land surface into soil or porous rock. infiltration – when the water enters the soil surface after falling from the atmosphere.

10 An aquifer is a natural underground area where large quantities of ground water fill the spaces between rocks and sediments and creates and underwater “pool” of water. This water is frequently pumped up using water wells and used for humans and livestock. The water table is the upper surface of ground water below which the soil or rocks are permanently saturated with water and where the pressure of water in the soil equals the pressure of the atmosphere. The water table fluctuates with the seasons and from one year to another based on how much precipitation has fallen, how much has been pumped out for human use and how much is used by plants and animals.

11 Less permeable rock below an aquifer that keeps groundwater from draining away is called a confining layer. The water held within the pores of the sand, soil, and clay above the confining layer is called an aquifer. Sometimes, deeper in the ground is an impermeable layer. When water is trapped between the confining layer and the impermeable layer, it forms an artesian aquifer. Water in an artesian aquifer is under a large amount of pressure and can bubble up out of the ground in some places. Rainwater cannot penetrate the confining layer to get to an artesian aquifer. Artesian aquifers are refilled in a recharge zone where there is no confining layer.

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16 Answer the following questions in complete sentences.
1. Which earth material had the highest porosity? Explain why. 2. Which earth material had the highest permeability (fastest time)? Explain why 3. Which earth material had the lowest porosity? Explain why. 4. Which earth material had the lowest permeability (slowest time)? Explain why. 5. Using your own words, define the following words: porosity - permeability - percolation - infiltration -

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19 Record you data for the experiment.
Calculate the percent porosity and record. Use this formula: % porosity = volume of pore space (amount of water) x 100 volume of material

20 Permeability Prezi Running Dry (25 min) Neuse River (10 min) FLOW (90) Blue Gold (90) Tapped Preview


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