Landforms

1. Landforms Investigation 1: Schoolyard Models Investigation 2: Stream Tables Investigation 3: Go with the Flow Investigation 4: Build a Mountain Investigation 5: Bird’s Eye View

2. Investigation 1: Schoolyard Models • Model- a representation of an object or process • Boundary- the limit or border of an area or region • Structure- something built by people, like a building • Map- drawing of an area • Cartographer- person who makes maps • Grid- network of vertical and horizontal lines that form squares

3. Investigation 1: Schoolyard Models • What information can be included on a map? Maps show roads, structures, and landforms as seen from above • How did you use the grid to help you make a map of your schoolyard model? The grid identifies the position of buildings and other features on the map.

4. Investigation 1: Schoolyard Models • Symbol- color, shape, or texture used to represent something else on a map, such as a building, road, or landform. • Key- an explanation of symbols used on a map • Why is it important to include a key on a map? A map key explains what the symbols mean on a map

5. Investigation 2: Stream Tables • Drainage basin- system of rivers and streams that drains an area like the Colorado Plateau • Erosion- involves 2 processes • Weathering- wearing away by water, wind, ice • Transport- movement of materials to new locations by water, wind, or ice

6. Investigation 2: Stream Tables • Landform- shape or feature of the Earth’s surface • Canyon- a V-shaped valley eroded by a river or stream • Delta- fan shaped (triangular) deposit of earth materials at a mouth of a stream • Plateau- large, nearly level area that has been lifted above the surrounding area

7. Investigation 2: Stream Tables • What happens when a river flows over a flat surface like a plateau? Water flowing over earth materials may erode them. • What are some of the landforms that can be created by rivers? Rivers can create landforms called canyons and deltas. • Where does most of eroded earth material end up after the water moves through the stream table? Sand forms the delta, and clay ended up in the basin

8. Investigation 2: Stream Tables • Why do you think the sand was deposited at the bottom and the clay on top of the vial when it was shaken? The sand is heavier and settled to the bottom first when the shaking stopped. • Where does water slow down first in the stream table? The water starts to slow down near or at the mouth of the stream. You can observe the movement of the water by watching the particles it carries along.

9. Investigation 2: Stream Tables • How does the result of the shake test explain why the sand and clay were deposited in different places in your stream table? The sand is heavier, so it is deposited first. The clay is carried farther before it’s deposited because it’s lighter. • A canyon is created by erosion • A delta is created by deposition

10. Investigation 2: Stream Tables • Why does water move back and forth in a channel? Water always flows to the lowest place. Water will move around barriers if possible. • Deposition- process by which eroded earth materials settle out in another place • Sediments- eroded earth materials that have been deposited

11. Investigation 2: Stream Tables • Basin- low area in which sediments are often deposited • Channel- course or path the water takes in a stream or river • Meander- curve or loop in a channel • What happens to earth materials that have been eroded by a river? They are deposited as sediments in a basin

12. Investigation 2: Stream Tables • Which earth materials are deposited first as water in a river slows down? Heavier earth materials are deposited first (sand then clay) • What happens to water flowing in a river? It moves back and forth following the lowest channel • How could the Colorado River have formed the Grand Canyon? It might have eroded earth materials that make up the Colorado Plateau

13. Investigation 3: Go with the Flow • Slope- angle or slant of a stream channel or land surface • Alluvial fan- fan-shaped landform deposited at the end of a steep canyon where the slope becomes flatter. Fans are usually found in arid regions like Death Valley

14. Investigation 3: Go with the Flow • What differences did you observe in the landforms when the slope increased? The canyons were deeper; the deltas were larger and longer. Water flowing through channels with steep slopes causes more erosion • How did slope affect the time it took for landforms to appear? Material eroded faster in the slope tray, so the canyon took less time to form.

15. Investigation 3: Go with the Flow • What happens to flood waters when they reach another body of water like a lake? Water slows and material is deposited. A delta forms • Where did you see a delta in your stream table? Where the stream reached the pool of water. • What might happen in the Grand Canyon when there is a flash flood? More erosion might occur, and the canyon might become deeper.

16. Investigation 3: Go with the Flow • What might make water in a stream channel slow down? The slope might become more flat. The water might run into a lake or ocean • What would you expect to see where slope changes? Eroded earth materials would be deposited. A delta or alluvial fan could form.

17. Investigation 3: Go with the Flow • How can you use what you know about flooding and increased volume of water to explain why rivers could flow more quickly over a flatter slope as they approach their mouths? At its mouth a river is probably carrying a greater volume of water because other streams in its drainage basin have joined it along the way

18. Investigation 3: Go with the Flow • Flood- a very heavy flow of water which is greater than the normal flow of water and goes over the stream’s normal channel • Flash Flood- rises and falls rapidly with little or no advance warning. It is usually the result of a very heavy rainfall over a relatively small area. Flash floods can be caused by sudden heavy rainfall, dam failure, or an ice jam thaw

19. Investigation 3: Go with the Flow • What differences did you observe in the landforms when you used the flood water source? The canyons were wider and straighter; the deltas were larger and longer. More material eroded • What differences did you notice in how long it took for features to form in the standard flood setups? The material started to erode earlier in the flood setup. Most events happened earlier.

20. Investigation 3: Go with the Flow • Levee- embankment along a stream that protects land from flooding. Levees can be manmade or natural • Dam- construction or wall across a river that holds back the water flowing through the river, creating a reservoir or lake. • Floodplain- area around a river that is covered by water flowing over the riverbank during a flood

21. Investigation 3: Go with the Flow • What are the different ways people use to control the flow of water in a river or stream? They build dams, levees, and new channels for the river

22. Investigation 4: Build a Mountain • Base- bottom of a mountain • Contour line- line on a topographic map that connects points of equal elevation • Contour interval- difference in elevation between contour lines • Elevation- vertical distance or height above sea level • Sea level- average height of ocean’s surface- zero elevation • Topographic map- uses contour lines to show the shape and elevation of the land’s surface

23. Investigation 4: Build a Mountain • What is a contour line and where is it used? Contour lines show the shape and elevation of the land on a topographic map • If a topographic map has many contour lines spaced close together, what does that tell you about the land’s surface in that area? The slope of the land is steep

24. Investigation 4: Build a Mountain • Profile- side view or cross-section of a landform such as a mountain • What kind of information can you get about a landform by looking at its profile? Profiles give a side view of a landform. They are a way to picture the slope of a mountain

25. Investigation 4: Build a Mountain • Bench Mark- surveyor’s marker usually placed permanently in the ground at a known position and elevation • Intermittent stream- has water flowing in it only during certain times of the year • Perennial stream- always has water flowing in it

26. Investigation 4: Build a Mountain • What kind of information do you usually get from a topographic map? Topographic maps give information about elevation and the shape of the land. Symbols and patterns on a key can give information about certain types of landforms such as intermittent and perennial streams

27. Investigation 5: Bird’s Eye View • Ridge- narrow area of high land between two valleys • Glacier- large mass or body of moving ice • Valley- low area between higher areas through which a river or stream often flows • Interpret a map- figure out the symbols, textures, colors, and patterns to put together an image of the land covered by the map

28. Investigation 5: Bird’s Eye View • Aerial photograph- picture of the earth’s surface taken from an airplane or spacecraft flying above the earth • Scale- describes the ration between a measured distance on a map to the actual distance in the real world • Surveyor- measures and marks the distance, elevation, position, and boundaries of land areas

29. Investigation 5: Bird’s Eye View • Bar scale- ruler line on a topographic map that shows the scale • Representative fraction- tells the scale of a map as a ration between distance on a map to distance in the real world • What kind of information do you get from an aerial photograph? Aerial photos give an actual picture of the earth’s surface, so you can see the trees, valleys, bodies of water, and more

30. Investigation 5: Bird’s Eye View • What are some ways aerial photos might be used? Surveyors can use them to record their measurements. Cartographers use these measurements and aerial photos to help them draw topographic maps • Rapids- part of a river channel where the water moves rapidly over obstacles, such as large boulders. This is a landform on the Colorado River in the Grand Canyon

31. Investigation 5: Bird’s Eye View • Intermittent Lake- contains water only during certain times of the year, such as the rainy season. This is a landform in Death Valley • What kinds of features can you view on a topographic map and aerial photos? Landforms, other natural features, and human constructions

32. Investigation 5: Bird’s Eye View • How can you tell you are looking at the same feature on a topographic map as you are on an aerial photo? You need to find similar landmarks on both. For example, alluvial fans are fan-shaped on the photos. The contour lines on a topographic map are also fan-shaped or parts of concentric circles