34 terms

Geology 3 Ch. 10

____ refers to sand grain movement in a series of short leaps or bounces off the bottom
Continental divide
In North America, the ___ separates streams that flow into the Pacific Ocean from those that flow into the Atlantic Ocean and Gulf of Mexico.
A(n) ____ stream is one that exhibits a delicate balance between its transporting capacity and the sediment load available to it
A "100-year flood" has a _______ percent chance of occurring in any given year
The limit to downcutting of a stream is called the ___ level
____ meanders are meanders that retain their sinuous pattern as they cut vertically downward below the level at which they originally formed
Stream terrace
A(n) ___ is a step-like landform found above a stream and its floodplain. It is a remnant of an older flood plain or river-eroded flat surface
Movement of cobbles and boulders by rolling, sliding, or dragging in a streambed is called ____ load.
Down cutting
The process of deepening of a valley by erosion of a streambed is called __
On large alluvial fans, the _____ sediment is deposited near the mountains
Natural levees
_____ are low ridges of flood-deposited sediment that form on both sides of a stream channel and thin away from the channel
Recurrence interval
Floods are described by ____, the average time between floods of a given size
Oxbow lake
A cutoff meander may become a crescent-shaped __
A graded stream can be deepening its channel by down cutting while part of its energy is also widening its valley by ______ erosion
Artificial levees
Flood control structures along the Mississippi River surrounding New Orleans are predominantly ____
A _____ is a ridge of sediment built by sedimentation on the middle or banks of a stream channel
All of above
Streams erode rock and sediment by ___
Channel shape & roughness
___ influences the velocity of a river along with gradient
A(n) ___ stream flows in a network of rivulets (subchannels) around numerous sandbars
A(n) ___ drainage pattern of a river resembles a tree.
The ______ load is sediment light enough to remain lifted indefinitely above the bottom by water turbulence
A ____ drainage pattern is one in which streams diverge outward likes spokes on a wheel
Flash floods
___ is/are sudden localized floods of large volume and short duration, often triggered by heavy rainstorms
A(n) __ is the body of sediment deposited at the mouth of a river when the river's velocity decreases
All of above
A stream can increase its length by ____
stream's discharge
A ___ is the volume of water passing through a specific point along the stream in a unit of time.
Rivers may develop pronounced sinuous curves called a ___ pattern
Natural levees
_____ are low ridges of flood deposited sediment that form on either side of a stream channel and thin away from the channel
Drainage basin
The ______ is the total area drained by a river and its tributaries
Sliding & rolling
The gravel bed load of a stream moves by ___
Stream velocity
Discharge is the product of average stream width times average stream depth times ___
A river's velocity is ___ along the outside of a meander loop near the cut bank
A ridge or strip of ground separating one drainage basin from another is termed a ___
Hydrologic cycle
The movement and interchange of water between the sea, air and land can be visualized by the ____