WATER EROSION
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Transcript of WATER EROSION
WATER EROSIONEROSION AND DEPOSITION
Runoff and Erosion Precipitation over the United States averages
about 75 cm per year. About 22.5 cm becomes runoff. Generally, more runoff means more erosion.
Runoff and Erosion Water flowing across the land runs
together to form rills, gullies, and streams.
Erosion by Rivers A waterfall forms where a flat layer of tough rock lies
over a layer of softer rock that erodes easily. When the softer rock erodes, pieces of the harder rock above break off, creating the waterfall’s sharp drop.
Erosion by Rivers Erosion often forms meanders and oxbow
lakes where a river winds across its floodplain.
Deposits by Rivers Deposition creates landforms such as alluvial
fans and deltas.
Alluvial Fan
The Course of a River The slope and size of
a river, as well as the sediment it carries, determine how a river shapes the land.
Groundwater Erosion Karst topography is found in many parts of the
United States where the bedrock is made up of thick layers of limestone.
Groundwater Erosion Chemical weathering of limestone and
groundwater erosion can create a limestone cave.