7. 1. The amount of rain an area receives.
2. Vegetation - grasses, shrubs & trees
reduce runoff
3. Type of soil - some absorb more water
than others
4. Shape of the land – steep slopes have
more run-off, which causes more erosion
5. How people use the land – parking lots &
crop removal increase run-off
9. Rills & Gullies
Rills are tiny grooves in the soil
that grow larger forming gullies.
A gully is a large groove or channel
in the soil that carries runoff after
a storm. It moves soil & rocks.
Gullies only contain water after it
rains.
12. Streams & Rivers
Gullies join together to form a larger
channel called a stream.
Water continuously flows here and
rarely dries up.
Small streams may be called creeks or
brooks.
Small streams flow together to form a
large stream called a river.
13. Rill,
Rill erosion at a
construction site.
Image by M. Mamo, Labels
added by UNL
Gully,
Stream
Gully erosion in a pasture.
Image by NRCS
Stream
14. Tributaries
Streams grow together by getting
water from tributaries.
A tributary is a stream or river that
flows into a larger river.
An example: The Missouri & Ohio rivers
are tributaries of the Mississippi river.
Tributaries collect their water from the
drainage basin or watershed.
20. Waterfalls
Occur where?
Where a river meets an area of hard &
slowly eroding rock
Then flows over softer rock downstream.
How does softer rock erode? What
results from this erosion? The softer
rock erodes away faster & a waterfall
develops.
21. Waterfalls
Waterfalls at the
Plitvicka Jezera National Park in Croatia
Minnehaha Falls,
Minneapolis Minnesota
http://images.google.com/imgres?imgurl=http://realestate-inminnesota.com/images/Minneapolis.jpg&imgrefurl=http://realestate-inminnesota.com/&usg=__kBYWaWcelJlC-sNAEDq6zr8eLY=&h=599&w=800&sz=162&hl=en&start=5&um=1&tbnid=WO5G4jC_rIKDMM:&tbnh=107&tbnw=143&prev=/images%3Fq%3Dminnehaha
%2Bfalls,%2Bmn%26ndsp%3D18%26hl%3Den%26sa%3DG%26um%3D1
22. Flood Plain
What is a flood plain?
A wide valley in which a river flows
What happens to the land during a
flood?
The water in the river over flows its
banks into this wide river valley area.
29. Soil may also be added to
Flood Plains during floods as
sediments are deposited.
This new soil added to the
area makes the river valley
fertile.
Forests and crops may be
grown here.