Erosional/Depositional Systems

Running Water/Streams

Running Water/Streams

a. Carrying Power – How much material can the stream hold

1. Solution – dissolved particles

2. Suspension – carrying of fine sediments (they are suspended in water)

3. rolling, sliding or bouncing along the bottom >> Bedload

Velocity of a Stream = speed

• The _________ the stream, the ______ it can carry

• ESRT Page __

• When a stream slows down, it loses its carrying power and particles are deposited

faster more

6

What’s the minimum speed water needs to be moving in order to transport sand? _________

In order to move a particle that is 7.0 cm, a stream’s velocity would need to be at least _________ cm/sec

0.3 cm/sec

200

Velocity is dependent on:• i. Gradient - Gradient (slope) increases,

Velocity increasesDirect relationship

Velocity is dependent on:

• ii. discharge

As discharge increases, velocity ____________increases

_________ relationshipDirect

Velocity is dependent on:

• iii. Channel Shape

• Meander = curve of stream or river

• If a stream is meandering, then velocity is greatest on the outside

• If stream is straight, velocity is greatest in the center just below surface (less friction)

http://www.wwnorton.com/earth/egeo/flash/14_1.swf

iii. Channel Shape

outside of the bend, greater velocity on the outside

the inside, less velocity so particles are dropped

• Erosion on

• Deposition on

ELBOW = EROSION

DENT = DEPOSITION

EROSION

DEPOSITION

What happens when a stream reaches a large body of water?

High potential energy(top of hill) Mouth - where river enters ocean

Low potential energy,low velocity

Velocity __________ as distance from the mouth ________, ______ particles settle out first

decreases increasesLarge

EROSIONAL EFFECTS

• A. Particles become round and smooth due to ____________

• B. V-shaped ValleysAbrasion

c. Graded Bedding

Fastest Velocity

Slowest Velocity

Big Particles

SmallParticles

c. Graded bedding

Life Of A Stream

NEW MATURE OLD

Life of a Stream

Oxbow Lake - cut off from main flow

http://www.school-portal.co.uk/GroupDownloadFile.asp?file=21606

Watershed - Area of land drained by one stream

Deposits atmouth of river

A flat land next to a river that is subject to flooding

Where river begins

Streams that flow into rivers

• 4,520 square miles of land area within New York State

Chenango River (2,796 river/stream miles)

• http://www.youtube.com/watch?v=adlGxr7wovU