Transcript Water on the Surface What is a river system?

Water on the Surface
What is a river system?
A river system
includes a
river in
addition to
any streams
or tributaries
that flow into
that river.
Tributary
The smaller streams
and rivers that
feed into a main
river.
Tributaries
• Tributaries
flow toward
the main
river.
• They follow
a downhill
path.
• What force
causes this?
Watershed
The land area that
supplies water
to river system.
Amazon River
Basin
Largest
watershed
in the
world.
Divide
A ridge that separates one
watershed from another.
Lakes and Ponds
Lakes and
ponds form
when water
collects in
hollows and
low-lying
areas of land.
Ponds
Ponds are thriving habitats for various plants
and animals.
Algae serves as food for many animals.
Ponds are typically very shallow and
sunlight can reach plants on the bottom.
Lakes
Lakes are bigger
and deeper than
ponds.
Lake bottoms
consist of sand,
pebbles and rock.
Lakes
Lakes can form from:
1. cut-off meandering rivers (oxbow lakes)
2. Erosion by ice.
3. Extinct volcano craters
4. Movements of Earth’s crust.
5. Manmade lakes are formed by river
dams.
Oxbow Lake
Lakes- Human Uses
Drinking water
Irrigation
Boating
Fishing
Reservoir- a lake that holds water for human
use.
Lake Turnover
When the water in a lake mixes due to
temperature change causing minerals,
plant matter, and other nutrients to rise to
the surface.
This refreshes the nutrients of the lake.
Eutrophication
When nutrients build up in a lake over many
years.
Algae forms a thick green scum on the
surface of the water.
Icebergs
Large chunks that
break off of a
glacier and float
away into the
ocean.
Made of frozen
FRESHWATER.