Transcript Surface Water ppt Parts 1 and 2

“Where’s Water?” Unit: Surface Water
Rivers, Lakes, and Ponds
River Systems

The streams and smaller rivers that feed into
a main river are called tributaries
 Tributaries flow downward toward the main
river, pulled by the force of gravity
 A river and all its tributaries together make
up a river system
River Features
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Headwaters
Tributaries
Flood plain
Oxbow lake
Meander
Mouth
Delta
Estuary
River Features

The many small streams that come together
at the source (beginning) of a river are
called its headwaters
 The steep slope of the land causes the river
to flow quickly
River Features

Meanders-looping curves in a river
 Meanders can curve back on themselves.
The river may then cut a new, straight
course, eventually leaving an oxbow lake
Horseshoe
Bend
of the Colorado River
near Page, AZ
Ox Bow lake on Mississippi
River Features

The broad, flat valley through which a river
flows is its flood plain
River Features

The mouth of a river is where the river
flows into another body of water
 A delta is created when the river slows
down and deposits the sediment it was
carrying
Delta Formation
DEPOSITON OF MATERIAL BY THE RIVER
WHEN IT ENTERS THE SEA
Mississippi Delta from Space
MISSISSIPPI
Watersheds

The land area that supplies water to a river
system is called a watershed
 Watersheds are sometimes known as
drainage basins
 We live in the Delaware River Watershed
Divides

A ridge of land that separates one watershed
from another is called a divide
 Mountains are an example of a divide
Divides
Estuaries
 An
estuary is a
coastal inlet or
bay where fresh
water from rivers
mix with salty
ocean water
Surface Water Part II:
Ponds and Lakes
Ponds

Ponds are
freshwater
 Ponds are shallow
 Ponds form when
water collects in
low-lying areas of
land
 Plants grow at the
bottom of ponds
Lakes

Lakes are
freshwater
 Lakes are deep
 Lakes form when
water collects in
low-lying areas of
land
 Plants do not grow
at the bottom of
deep lakes
Lake Baikal, Russia
Lake Formation

Lakes can be formed by natural processes or
human efforts:
 1. Volcanic lakes
 2. Glacier- made lakes
 3. Human- made lakes
 A lake
that stores water for human use
is called a reservoir
Volcanic Lake
Glacier-Made Lakes
Human-Made Lakes
Lakes Can Change
 Seasonal
changes- water
temperature at different depths
changes during the year
 Lake turnover-nutrients mix
 Nutrients-substances such as
nitrogen and phosphorous that
plants and algae grow
Lakes Can Change

Long-term changes
 Eutrophication-Algae
and scum
forms on the surface of the water
 becomes so thick that it blocks out
sunlight and plants cannot carry out
photosynthesis
 Death of a body of fresh water
Eutrophication
Eutrophication
Ponds and Lakes
SAME
DIFFERENT
 Freshwater
 Lakes are deeper
 Still, standing water
 Plants don’t grow at
the bottom of deep
 Form when water
lakes
collects in hollows and
low-lying areas of land  Sunlight cannot reach
the bottom of a deep
lake and
photosynthesis cannot
occur
Crater Lake and Lake Nyos Links
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http://en.wikipedia.org/wiki/Crater_lake
 http://news.bbc.co.uk/onthisday/hi/dates/sto
ries/august/21/newsid_3380000/3380803.st
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