Water Erosion

1. Water Erosion Chapter 3 Section 2

3. Standard • S 6.2.a – Students know water running downhill is the dominant process in shaping the landscape • S6.2.b- Students know rivers and streams are dynamic systems that erode, transport sediment in natural and recurring patterns.

4. Anticipatory Set • Record how many drops a faucet releases in 1 minute • Place one bar of soap in a dry place • Place one bar of soap in a wet place • Let this go on for 10 minutes • What happened after 10 minutes to each bar of soap?

5. Vocabulary • Runoff-water that moves over earth’s surface • Rill- runoff forms tiny grooves in the soil • Gully- large groove, or channel that carries runoff from storms. • Stream- a channel that water is flowing down a slope • Energy- the ability to do work or cause change

6. VocabularyLanguage of the Discipline • Flood plain- flat, wide area of land along a river • Meander- loop-like bend in the course of a river • Oxbow lake- a meander that has been cut off from the river • Alluvial fan- a wide, sloping deposit of sediment- formed when a stream leaves a mountain range • Delta- sediment deposited where a river flows into a lake builds up a landform • Load- the amount of sediment that a river carries

7. Input

8. Input • Summer- water running, pebbles and sand move at the bottom of the river, it carries leaves downstream. Insects drink from the river • Winter- the stream freezes, chunks of ice grid away at the stream bed and banks. • Spring- stream floods and may be strong enough to move large rocks. • Streams- cause erosion because of the sediments it carries

9. Input • Runoff- water that moves over Earth’s surface. • Runoff that flows in a thin layer over the land is called sheet erosion. • 5 factors • Amount of rain • Vegetation • Type of soil • Shape of land • How people use the land

10. Input • Through erosion, a river creates valleys, waterfalls, flood plains, meanders and oxbow lakes. • Energy- the ability to do work • All along a river, the water’s energy does work. • Rivers often form on steep mountain slopes • Near the mouth of a river, it is fast flowing, and follows a straight and narrow course.

11. Input • Waterfalls- occurs when a river meets hard rock and erodes it slowly. It flows over the rock and then flows over softer rock downstream. • Softer rock wears away faster than harder rock • Floodplain- flat, wide area of land. This occurs when it overflows its banks during flooding

12. Input • A river is a dynamic system. • A rivers slope, volume of flow and the shape of its streambed all affect how fast the river flows and how much sediment it can erode. • The amount of sediment that a river carries is called a load. • Slope- if more water flows through a river, then its speed will increase. • Flow- the volume of water that moves past a point on a river in a given time

13. Video • Video Field Trip