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Chapter 1 - Lesson 2
Streams and Rivers, Lakes
Chapter 1
The Earth’s Bodies of Water
Streams and Rivers page 26
• Water covers more than 70% of the Earth
• Water is in the ground and in the air we
breathe
• People, Plants, and Animals all need water
to live
Weathering - is the process of breaking up rocks
into smaller pieces called sediment
Streams and Rivers
• Streams are bodies of water that flow over land in a
channel
• Most streams begin on high ground, among hills or
mountains
• The sources of a stream usually consist of melting
snow/ice or an overflowing lake
• At the end of a stream is the mouth which empties into
another body of water
Streams and Rivers
• Streams can be as small as a shallow brook
• Or as large as a river, the largest and most
important streams
• Most rivers form from many smaller streams
coming together, these are called tributaries
Tributaries – are streams or rivers that flow into
a larger stream or river
Streams and Rivers
• The more tributaries that empty into a river
the larger the river grows
• Together the river and its tributaries are
called a river system
River System – a river and all of its tributaries
Streams and Rivers
• Each continent, except Antarctica, has major rivers and
river systems.
• Africa has the Nile, Asia has the Yangtze, Australia has
the Murray, Europe has the Danube, North America has
the Mississippi, and South America has the Amazon
Streams and Rivers, Lakes
• The Nile is the Earth’s longest river, it flows from Central
Africa to the Mediterranean Sea
• The Amazon is the Earth’s largest river, carrying more
water than the Mississippi, Nile and Yangtze combined
• River Systems carry or drain water away from the land
around them (drainage basin)
Drainage Basin – Land drained by a river system
• Rivers are important for many reasons including
drinking, cleaning, travel and trade
Streams and Rivers
Drainage Basin
• Why did many of the world’s first settlements
form along rivers?
(pg.27)
Lakes
• Lakes are bodies of water surrounded by land
• The word lake comes from the Greek language meaning
hole because most lakes are holes in the Earth that fill with
water
• Lakes exist on every continent except Antartica
• The greatest amount of lakes exist where there was once
many glaciers such as North America and northern Europe
Lakes
• During the last Ice Age, glaciers gouged huge holes in the
Earth and the holes filled with the water from the melted
glaciers
• Lakes also form where rainwater collects in huge holes
made in other ways
• Crater Lake in Oregon was formed in a crater of an extinct
volcano
Lakes
• Lake Baikal in Russia is the deepest lake on Earth measuring
5,315 feet deep it was formed in a huge crack in the Earth’s
crust called a rift
Rift – a long and deep crack in the Earth
Lakes
• North America has the most lakes out of all of the
continents
• The largest of the North American lakes are the Great Lakes
• One fifth of all of the fresh water on the Earth’s surface is
found in the Great Lakes
H – Huron
O – Ontario
M – Michigan
E – Erie
S – Superior
Lakes
• There are some large bodies of water called seas
that are actually lakes
• The difference is that they are not fresh water, but
salt water and that is why they are called seas
instead of lakes
• The Dead Sea, Sea of Galilee, and the Caspian Sea
are lakes
• The lowest lying lake is the Dead Sea between
Israel and Jordan
• The highest lake is Lake Titicaca in South America
Lakes
The Dead Sea
Lakes
Lake
Titicaca
Lakes
• Not all lakes are made by nature
• Some are man-made and are called resevoirs
• People build dams to control river flooding or to generate
electricity
Reservoir – a lake that forms behind a human made dam
Terms to Know
• Reservoir
• Rift
• Drainage basin
• River system
• Tributaries
• How did Ice Age glaciers form lakes in
North America and Europe? (pg. 28)