Structures of the Hydrosphere Labs P. McAven 8th Grade Science Riverwood Middle School 2016 - 2017

Think About It  Where can drinking water come from? 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?

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).

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.

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?

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?

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.

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.