Water Erosion
Chapter 3 Section 2
Pages 72-81
Moving water is the major agent of the erosion that has
shaped Earth’s land surface.
Run-Off: The water that moves over Earth’s surface.
More run-off means more erosion.
Things that reduce run-off (like plants and roots) reduce
erosion.
In wet areas, run-off & erosion may be low because there
are more plants to protect the soil.
Run-Off flow chart:
Rills ->
Gullies ->
Streams ->
Rivers
Tributary: A stream or river that flows into a larger river.
Through erosion, a river creates valleys, waterfalls, flood
plains, meanders, and oxbow lakes.
Waterfalls: Occur where a river meets an area of hard
rock that erodes slowly, while eroding softer rock quickly.
This will eventually develop a waterfall.
Flood Plain: The flat wide area of land along a river.
Meander: A loop-like bend in the course of a river.
Oxbow Lake: Is a meander that has been cut off from
the river.
Deposition creates landforms such as alluvial fans and
deltas. It can also add soil to a river’s flood plain.
Alluvial Fan: A wide, sloping deposit of sediment formed
where a stream leaves a mountain range.
Delta: Sediment deposited where a river flows into an
ocean or lake.
Beaches: Sand carried downstream by the river spreads
along the coast to form beaches.
Groundwater: Underground water
*Groundwater can cause erosion through a process of
chemical weathering.
Stalactite: A deposit that hangs like an icicle from cave
ceiling.
Stalagmite: A cone-shaped deposit on cave floor.
Karst Topography: A landscape created from sinkholes.
These sinkholes were caused by the erosion of underlying
Limestone. (Found in Florida and Texas for example.)