Water Erosion Chapter 3 Section 2

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.

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?

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

Vocabulary Language 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

Input

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 grig 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

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

Input During sheet erosion, runoff forms tiny grooves called rills Sheet Erosion- begins when runoff from rainfall flows in a thin layer over the land A gully is a large groove that carries runoff from a rainstorm. It moves soil and rocks only after it has rained. Stream- continually flowing down a slope Starts off as a stream, then becomes a river as it gets bigger. Tributary- a stream or river that runs into another stream or river.

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

Input Meanders- loop like bend in the course of a river. It erodes the outer bank and deposit sediment on the inner bank of a bend. It can erode a wide flood plain. It’s channel is deep and wide Oxbow Lakes- meander that has been cut from the river. Forms when a river floods. When flood waters fall sediments dam up the ends of a meander and it has become an oxbow lake.

Input Deposition creates landforms such as alluvial fans and deltas. It can also add soil to a river’s flood plain. Alluvial fans- wide, sloping deposit of sediment formed when a stream leaves a mountain range. Flows out of steep and narrow mountain range and suddenly becomes wider and shallower. Deltas- sediment (deposition) deposit where a river flows into an ocean or lake builds up a landform. Delta of the Nile in Egypt is shaped like a triangle. They can be all different shapes.

Checking for Understanding What is a gully? What is a flood plain? What is a meander? Describe a delta

Guided Practice Independent Practice GP- page 56 # 1-19 Stop and have teacher look at answers IP- Water Erosion Worksheet