Shared Flashcard Set

Details

BSS ESC11 CH 10 vocab
10 vocab
20
Science
11th Grade
12/12/2008

Additional Science Flashcards

 


 

Cards

Term

Abrasion

[image]

Definition
A form of mechanical weathering that occurs when loose fragments or particles of rocks and minerals that are being transported, as by water or air, collide with each other or scrape the surfaces of stationary rocks.
Term

alluvial fan

[image]

Definition
 A triangular deposit of sediment left by a stream that has lost velocity upon entering a broad, relatively flat valley.
Term

base level

[image]

Definition
The lower limit of erosion by a stream. Sea level is the ultimate base level. However, lakes can serve as a temporary base level in upstream areas.
Term

bed load

[image]

Definition
The larger, heavier particles that are being transported by a stream. Instead of being dissolved or suspended, these are being rolled or bounced along, spending at least part of their time in contact with the stream bottom. See also: load, suspended load, dissolved load.
Term

delta

[image]

 

Definition
A deposit of sediment that forms where a stream enters a standing body of water such as a lake or ocean. The name is derived from the Greek letter "delta" because these deposits typically have a triangular shape in map view.
Term

discharge

[image]

Definition
The volume of water in a flowing stream that passes a given location in a unit of time. Frequently expressed in cubic feet per second or cubic meters per second. Calculated by the formula Q = A x V where Q is the discharge, A is the cross sectional area of the channel and V is the average velocity of the stream.
Term

divide

[image]

Definition
A ridge that separates two adjacent drainage basins.
Term

drainage basin or watershed

[image]

Definition
The geographic area that contributes runoff to a stream. It can be outlined on a topographic map by tracing the points of highest elevation (usually ridge crests) between two adjacent stream valleys. The watershed of a large river usually contains the watersheds of many smaller streams. Also referred to as a "drainage basin".
Term

flash flood    

     [image]

Definition
A flood that occurs within a few hours (usually less than six) of heavy or excessive rainfall, dam or levee failure.
Term

flood plain

[image]

Definition
An area of alluvium-covered, relatively level land along the banks of a stream that is covered with water when the stream leaves its channel during a time of high flow.
Term

gully

[image]

Definition
deep ditch cut by running water (especially after a prolonged downpour)
Term

headward erosion

[image]

Definition
In hydrologic terms, erosion which occurs in the upstream end of the valley of a stream, causing it to lengthen its course in such a direction.
Term

levees

[image]

Definition
A protective barrier built along the banks of a stream to prevent flooding. See also natural levee.
Term

meanders

[image]

Definition
are looping changes of direction of a stream. These may be somewhat sine-wave in form. Typically, over time, the meanders don't disappear but ...
Term

oxbow lake

[image]

Definition
A crescent-shaped lake that forms when a meandering stream changes course. Such changes in course frequently occur during flood events when overbank waters erode a new channel.
Term

pothole

[image]

Definition
A cylindrical or hemispherical hold in the bedrock of a stream that is formed from the continual swirling motion of sand and gravel by swirling currents.
Term
solution
Definition
A chemical weathering process in which a material is dissolved. Also, the transport of dissolved ions by the water of a stream.
Term

stream piracy

[image]

Definition
A level plain lying above and running parallel to a stream bed. A stream terrace is formed when a stream's bed erodes to a substantially lower level, leaving its floodplain high above it.
Term

water gap

[image]

 

Definition
An opening in a resistant ridge where a trunk river has cut through the ridge.
Supporting users have an ad free experience!