Transcript File

Landforms
 Erosion – the process of
water (wind or ice)
wearing or washing away
earth material.
 Large volumes of earth
material wash away
more earth material
 Fast water increases the
amount of erosion and
moves earth material
farther
 Rivers
and
streams
Desposition
The process
where earth
materials are
picked up by
water, wind or
ice and put
down in another
place.
Rivers and streams
 Deposition- earth material
drops out of water as it slows
down. Smaller particles like
clay take longer to settle. They
stay suspended in the water
longer.
 Order of settlement or
deposition:
Boulders, rocks, pebbles, sand,
silt, clay
Clay is deposited on the banks of
slow moving streams.
Streams
 Intermittentcome and go
with the seasons
and weather
conditions
 Some lakes are
also intermittent.
 Perennialalways flowing
though not
necessarily at the
same level.
Deltas
 Deltas are large fan
shaped deposits of
earth material at the
mouth of streams and
rivers.
 Alluvial Fans- are very
large deltas formed when
there is a sudden change
from a steep slope to a flat
plain. They are often very
fertile deposits of soil.
Famous Rivers
 Mississippi
The Mississippi was formed from a
glacier in the last ice age.
a. the floodplain is miles wide below
St. Louis and the sediment causes very
fertile land.
b. the wide channel from St. Paul to
the Gulf of Mexico is very important for
transporting grain.
The Hudson River flows from the
Adirondack Mountains through New
York State to the Atlantic Ocean.
a. Its mouth (near New York City) is
below sea level so it is affected by tides
and is salty.
b. It flows through steep rock cliffs
called palisades.
c. It provided waterpower for
lumber and textile mills.
d. The Erie Canal connects the
Hudson with Lake Erie
Colorado River
Formed the Grand Canyon
Provides water and power (Hoover
Dam) for much of the Southwest.
Maps
general reference-used to locate places and boundaries
(political maps), and show geographic features (physical
maps).
mobility- help people move from one place to another, roads,
railroads etc.
thematic- shows such things as population or weather patterns
inventory – shows location of objects (stadium map, building
map)
Topographic- shows physical features of a landscape including
contour lines and elevations.
Making maps
gather data-(observe the playground)
make careful measurements
record information (rocks, forests, etc.)
Models- smaller versions of large objects,
larger versions of small objects -can
represent landforms and human
structures
Maps- can represent landforms and
human structures
Cartographer- person who makes maps
Horizontal and vertical lines
evenly placed called
grid lines are often used on maps.
They allow easy reference points
and make it easier to enlarge
And shrink maps.
The gridlines are labeled with an
X and Y axis.
Topographic or
Contour map
Contour lines- lines that
connect points of equal
elevation
Contour interval- difference
in elevation between contour
lines-the closer the lines, the
steeper the slope.
Bar scale- shows the
relationship between the
distances on the map and the
distance on the ground
Scale: Ratio or fraction
showing the distance on the
map compared to the distance
on the ground.
(Representative fraction)
Example 1:6,150
Topographic maps cont.
The distance, elevation, position, and
boundaries are measured by a surveyor.
A surveyor puts permanent markers in
place called benchmarks to show
elevation and location.
0 elevation is sea level