Running WaterRunning Water

6.16.1

Water Water EverywhereWater Water Everywhere

About 97.2% of water is in oceans

Ice sheets and glaciers = 2.15%

.65% = divided among lakes, streams, groundwater, and the atmosphere

About 97.2% of water is in oceans

Ice sheets and glaciers = 2.15%

.65% = divided among lakes, streams, groundwater, and the atmosphere

The Water CycleThe Water Cycle

Unending circulation of Earth’s water supply Water changes

states Powered by the

sun

Unending circulation of Earth’s water supply Water changes

states Powered by the

sun

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The Water CycleThe Water Cycle

1. Evaporation = liquid to gas Water evaporates from oceans and

continents into atmosphere

2. Condensation = gas to liquid Moisture condenses into clouds

3. Precipitation = rain and snow Falls into oceans = 1 full cycle Falls onto land = must make its way back

to oceans

1. Evaporation = liquid to gas Water evaporates from oceans and

continents into atmosphere

2. Condensation = gas to liquid Moisture condenses into clouds

3. Precipitation = rain and snow Falls into oceans = 1 full cycle Falls onto land = must make its way back

to oceans

The Water CycleThe Water Cycle

4. Runoff = when rate of rainfall exceeds Earth’s ability to absorb it, excess water flows over the surface into lakes and streams

5. Infiltration = water soaks into land and seeps into lakes, streams, oceans

6. Transpiration = evaporation of water from plants

4. Runoff = when rate of rainfall exceeds Earth’s ability to absorb it, excess water flows over the surface into lakes and streams

5. Infiltration = water soaks into land and seeps into lakes, streams, oceans

6. Transpiration = evaporation of water from plants

How the Water Cycle Works

How the Water Cycle Works

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Earth’s Water BalanceEarth’s Water Balance

Water cycle is balanced Average annual

precipitation on Earth = amount of water that evaporates

Can have local imbalances Wind belts Precipitation exceeds

evaporation over continents

Water cycle is balanced Average annual

precipitation on Earth = amount of water that evaporates

Can have local imbalances Wind belts Precipitation exceeds

evaporation over continents

StreamflowStreamflow

Water moves downslope due to gravity Ability of stream to erode and transport

materials is due to its velocity Velocity = distance/time Velocity influenced by:

1. Stream’s gradient2. Shape, size, and roughness of channel 3. Stream’s discharge

Water moves downslope due to gravity Ability of stream to erode and transport

materials is due to its velocity Velocity = distance/time Velocity influenced by:

1. Stream’s gradient2. Shape, size, and roughness of channel 3. Stream’s discharge

GradientGradient Gradient = slope or steepness of a

stream channel Steeper the gradient = more

energy the stream has

Gradient = slope or steepness of a stream channel

Steeper the gradient = more energy the stream has

GradientGradient

Channel CharacteristicsChannel Characteristics Stream channel = main

path of the river or stream

Water flows --> friction from sides and bottoms of channel Channel filled with

boulders decreases velocity

Channel with sand and clay (smooth) increases velocity

Larger channels = more efficient water flow

Stream channel = main path of the river or stream

Water flows --> friction from sides and bottoms of channel Channel filled with

boulders decreases velocity

Channel with sand and clay (smooth) increases velocity

Larger channels = more efficient water flow

DischargeDischarge

Discharge = volume of water/time Meters3 per second

Impacts channel size and velocity Additional water =

channel widens and deepens

Additional water = less friction --> water moves faster

Discharge = volume of water/time Meters3 per second

Impacts channel size and velocity Additional water =

channel widens and deepens

Additional water = less friction --> water moves faster

DischargeDischarge Urbanization around a stream

channelMore pavement (streets, parking lots,

buildings) = increases surface runoff Less water soaks into ground

Urbanization around a stream channelMore pavement (streets, parking lots,

buildings) = increases surface runoff Less water soaks into ground

The Effects of Urbanization The Effects of Urbanization

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