Download 10.2

11.2
Stream and River Deposits
Even though flooding along rivers is potentially
harmful, many farms are located near rivers. Why
do people build along rivers?
Floodwaters bring fertile sediment deposits, which
enrich the soil. Rivers supply a method of
transportation for goods.
Deposition
• The process in which material is laid
down or dropped.
Deposition
Sediment
• Rock and soil that are
deposited by streams.
Deltas
• A fan-shaped pattern that is created when a
•
river may deposit its load.
Forms on a flat surface and is made mostly of
mud.
Delta
Alluvial Fans
• Fan-shaped deposits of
•
material, that unlike
deltas, form on dry
land.
Found in some desert
regions of California.
How are deltas and alluvial fans examples of
ways in which rivers streams change Earth’s
landscape?
* Rivers and streams change Earth’s landscape
by carrying sediment from one place to another.
Deltas and alluvial fans result when the river or
stream’s load is deposited.
Flood
• When a stream overflow its banks.
Floodplain
• The area
along a river
that forms
from
sediment
deposited
when a river
overflows its
banks.
Floodplain
River Flood
..\..\video clips\11.2 River and Stream
Deposits\Explanation_of_Flooding__Watershed__River__and_Flood_Plain_as
f.asf
Dam
• A barrier that can redirect and hold a portion of
the floodwater in a reservoir.
Dam
_
Levee
• The buildup of
•
sediment deposited
along the channel of
a river.
Helps keep rivers
inside its banks.
List two ways in which floods affect people.
* Floods can affect people by causing
property damage and death.
Review Questions
1. Why are floodplains both good and bad areas
for people to live?
* Floodplains form fertile farmland because
flood waters periodically deposit new soil on
the land. However, flooding can cause
property damage and endanger lives.
2. Describe three landscape features that form as a result
of stream deposition.
*Floodplains, alluvial fans, and deltas are three landscape
features that form as a result of stream deposition.
3. Floods are natural events. Why do humans try to
prevent floods?
* Humans try to prevent floods from occuring because
floods can cause property damage and death.