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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).
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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: Gradient (slope) increases, Velocity increases • i. Gradient - Direct relationship
ii. Discharge the amount of water
Velocity is dependent on: • ii. discharge As discharge increases, velocity ____________ increases _________ relationship Direct
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)
Where is erosion greatest? Outside of Curve
Where does the river flow fastest? Center down from surface
Where is deposition greatest? Inside of Curve Mouth of River
Why? lowest velocity
iii. Channel Shape • Erosion on • Deposition on outside of the bend, greater velocity on the outside the inside, less velocity so particles are dropped
DENT = DEPOSITION ELBOW = EROSION
EROSION DEPOSITION
What happens to particle size? Why? Decreases
What happens to particle size? decreases, because the velocity decreases
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 increases Large
EROSIONAL EFFECTS • A. Particles become round and smooth due to ____________ • B. V-shaped Valleys Abrasion
c. Graded Bedding SmallParticles Slowest Velocity Fastest Velocity Big Particles
Life Of A Stream NEW OLD MATURE
Life of a Stream Oxbow Lake - cut off from main flow
Oxbow Lakes
Watershed - Area of land drained by one stream Where river begins Streams that flow into rivers Deposits atmouth of river A flat land next to a river that is subject to flooding
4,520 square miles of land area within New York State Chenango River (2,796 river/stream miles)
delta What is this?
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