Freshwater Systems

• less than 1% of the water on Earth is available for us as freshwater

• freshwater exists as– surface water– groundwater

Surface Water

• lakes and ponds → standing water– in a pond sunlight

reaches the bottom– in a lake sunlight does

not reach the bottom• wetlands → areas

that are saturated with water

• rivers and streams → flowing water– speed, temperature,

clarity varies– more dissolved oxygen

than in standing water

Lakesnear shore, lots of plants

bottom-dwelling life that eats mainly waste from above

open water, affected by wind and currents

near surfa ce, lots of light & life

PROFUNDAL ZONEdeep & dark,

little life

Lake Succession

• sediments slowly fill in lake… and vegetation grows in from the sides

Rivers

• rivers are powerful forces… because they move they erode the land they flow over

• rivers can move vertically (cutting down) and horizontally (cutting sideways)

• rivers transport a lot of sediment with the water

• sometimes river channels get cutoff leaving an OXBOW LAKE

• old channels will eventually fill in like a lake

• rivers also dump tons of sediments into lakes and oceans

• sediments dropping out of suspension form deltas

Groundwater• most precipitation that falls on the Earth becomes

groundwater• groundwater sits just above bedrock

– the layer of saturated soil is called the WATER TABLE– the water table is closer to the surface in wet years… and

deeper from the surface in drier years• it is similar to a surface river system… except

underground• 25% of Albertans get their water from groundwater…

mainly for agriculture– when a well is drilled pressure forces groundwater to the surface

in the well• when groundwater gets heated up it often erupts to the

surface as a GEYSER

Run-off and Erosion• factors affecting run-off

– amount of precipitation & form (rain vs snow)– time it takes to fall/how fast it melts– slope of the land– type of soil– vegetation cover

• the movement of sediments from one place to another is called EROSION

• after sediments are transported they are deposited … this is called DEPOSITION

How can we reduce erosion?

Watersheds• the area of land that

drains into a body of water

• upstream areas or start of watershed is called HEADWATERS

• downstream areas or end of watershed is called OUTFLOW

Watershed Management• slow down water flow• keep vegetation on surface• protect river banks

– vegetation– rip rap

• direct water

Watershed Management

• control what goes into our waterways