Chapter 11 Rivers & Groundwater. 11.1 Notes – The Active River Water Cycle water cycle – the...
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Transcript of Chapter 11 Rivers & Groundwater. 11.1 Notes – The Active River Water Cycle water cycle – the...
Chapter 11
Rivers & Groundwater
11.1 Notes – The Active RiverWater Cycle
water cycle – the continuous movement of water from water sources, into the air, on to land, into the ground, and back to water sources
evaporation – liquid water from water sources changes into water vapor in the air due to heat from the sun
condensation – water vapor in the air changes into liquid droplets, forming clouds
11.1 Notes – The Active RiverWater Cycle
precipitation – rain, snow, sleet, or hail falls from the clouds on to the Earth’s surface
percolation – gravity pulls water that is already in the ground through the soil back to the water sources
11.1 Notes – The Active RiverWater Cycle
runoff – water flows across the ground or falls from the clouds and collects in rivers or streams
11.1 Notes – The Active RiverWater Cycle
What main source of energy drives Earth’s weather systems? Solar radiation (from the sun)
What drives the water cycle? The sun
weathering – the process by which sediment is broken off rock
erosion – the process by which sediment is picked up and moved to a new location
Erosion What are the 5 agents of erosion?
1. Wind
2. Water (rivers, streams, ocean waves)
3. Ice (glaciers)
4. Precipitation (rain, snow, sleet, & hail)
5. Gravity (causes landslides)
Erosion How can erosion happen fast?
A river overflowing leaving the side of the banks muddy
How can erosion happen slowly? Grand Canyon – the river eroding the surface
of the Earth slowly overtime
deposition – the process by which sediment is dropped due to lack of speed
Mountain Changes What can change the shape of a mountain?
Precipitation – rain, snow, sleet, and hail Runoff – forming rivers and streams Water flowing down hill can carry sediment because of
gravity Weathering, erosion, & deposition
What will form at the top of a mountain during precipitation? A stream with a few bends
11.1 Notes – The Active River load – the rocks and soil (sediment) carried in a stream’s
water Why would a river carry more of a load?
Because it has more water, because it is flowing fast, because it is on a hill or mountain, because water in a river can rise during precipitation
3 types of loads:1. bed load – large pieces of sediment like boulders and
pebbles2. suspended load – small pieces of sediment like small
rocks and sand – this makes the water look muddy3. dissolved load – dissolved material like sodium and
calcium – this makes the water look clear
11.1 Notes – The Active River meander – a curve or bend in a river or
stream What happens at a meander?
On the outside of the curve the water speeds up and erodes sediment
On the inside of the curve the water slows down and deposits sediment
channel – the path that a stream follows
Characteristics of the 4 stages of a river
youthful river – fast, waterfalls, steep gradient, bedload, deep not wide, erosion happens quickly
Characteristics of the 4 stages of a river
mature river – deep, slow, wide, not very steep, meanders, suspended load
Characteristics of the 4 stages of a river
old river – slow, wide, shallow, floods, meanders, dissolved load, a lot of sediment deposits, many times forms oxbow lakes
• oxbow lake – formed by an increase in the flow of water in a river causing the river to change course
Characteristics of the 4 stages of a river
rejuvenated river – land is raised by tectonic plates, steep cliffs above the river, river erodes valley floor
11.1 Notes – The Active River Why would one river have more sediment than
another river? More water = more sediment
What would give a river more water? precipitation
What are two ways that beaches get sand?1. Waves slow down and weather rocks depositing sand
2. Rivers end at the ocean creating a delta (deposited sediment)
11.1 Notes – The Active River Why does water flow downhill on a mountain?
Gravity – water always flows from higher elevations to lower elevations
How do you know if a river has recently flooded? There is wet mud on the ground
11.1 Notes – The Active River How could two mountains with a small stream in
between become flat 50 million years later? precipitation
What happened to the sediment? eroded by the stream and deposited in the ocean
Why would a river change course? floods
11.2 Stream
and RiverDeposits
alluvial fan – fan shaped deposits that form on dry land when a river or stream loses speed
delta – fan shaped deposits that form at large bodies of water such as the ocean when a river or stream loses speed This is one way beaches more sand.
11.2 Stream and River Deposits floodplains – an area along a river that
forms from sediment deposited when a river overflows its banks
Where would you find a lot of floodplains? On old rivers because they flood a lot