Water ErosionChapter 3Section 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

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

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 PracticeIndependent Practice

GP- page 56 # 1-19

Stop and have teacher look at answers

IP- Water Erosion Worksheet