Earth Science Chapter 14

What technique do the men in the villages of Bangladesh use to catch their fish?

The fishermen in the villages of Bangladesh fish using otters

What is suspended load?

The fine-grained particles that travel in the water column above the stream bed

Imagine a valley containing four stream terraces. Where would the youngest stream terrace be found?

The lowest terrace

Bangladesh has more than 700 rivers. What is the name of the country's primary river?

The primary river in Bangladesh is the Padma River

The flow of water is faster in what part of a river?

Water flows faster in the upper reaches of a river

When do streams erode laterally?

When downcutting is occurring in easy-to-erode sediment or rock

A stream is more likely to deposit its load of sediment when which of the following occurs?

When its speed decreases

When do stream terraces form?

When streams exist under alternating erosional and depositional conditions

As the discharge of a stream increases, which of the following also happens?

Width, depth, and/or velocity increase

Stream drainage patterns are determined by which of the following?

Climate, regional steepness and relief, landscape characteristics, and variations in rock resistance

Besides flood control, a(n) ___ can also be used to generate hydroelectric power. However, they are expensive to build and maintain.

Dam

This tree-like drainage pattern efficiently moves water and sediment through its system due to minimization of the total length of each branch.

Dendritic

Where do deposition and erosion of material occur along a meander?

Deposition occurs on the inside of the meander, whereas erosion occurs on the outside

An ___ is a bend in a steep narrow bedrock valley

Incised meander

If you live in an area that was flooded by the 100-year flood last year, you can conclude that

There is a 1% chance you could be flooded by the 100-year flood again this year

What is a river's primary job?

To transport silt, sand, and rocks (sediment) out of the mountains and down to the sea

Which processes result in the widening of the floodplain of a meandering stream?

Undercutting and lateral erosion

___ is/ are cheap to implement, but it/they can adversely affect property values

Zoning regulation

Often measured in "cfs" (cubic feet per second), the amount of water moving past a given spot over a given amount of time is referred to as a stream's

Discharge

What is the dominant fluvial process in a clear, sediment-poor stream moving down a steep slope?

Downcutting

The geographical area where all surface water converges to one location is called its

Drainage basin

What instrument was used in this video to measure flow rates in the river?

A water wheel was used to measure flow rates in the river

In Bangladesh life revolves around the water. What percent of this delta country floods each year?

Approximately 60 percent of Bangladesh floods each year

A(n) ___ confines water flow and can experience significant erosion. Constant maintenance is required

Artificial levee

As a river flows from its upper reaches to its lower reaches, how does the shape of the stream channel change?

As a river flows from its upper reaches to its lower reaches, it gets wider

Incised meanders and terraces are __________.

Erosional features

Processes that are related expressly to streams and rivers are termed

Fluvial

In a meandering river, where does most of the channel erosion occur?

In a meandering river, most of the channel erosion occurs on the outside bend of the stream

Complete this analogy: Sliding is to gravel as dissolution is to_____________.

Ions

This drainage pattern is associated with steep slopes

Parallel

Which one of the following represents a common way that water feeds into a stream bed?

A subterranean pool of groundwater reemerges as a spring

The ___ of a river have a steep gradient, high channel roughness, and low water volume.

Headwaters

A(n) ________ is a meander that becomes isolated from the rest of the river

Oxbow lake

How are oxbow lakes formed?

Oxbow lakes form when one meander erodes into another, cutting off water to part of the stream channel

This drainage pattern results when streams flow off a central peak or dome

Radial

The drop in stream elevation per unit distance is known as

Gradient

Which of the following are part of the bed load?

Gravel Sand

Maximum velocity in a straight channel is found

At the center and near the surface, corresponding with the deepest parts of the stream channel

Bangladesh's natural increase rate is high; how many people are added to the population in this country each year?

Bangladesh gains 2 million additional people per year

The lowest level to which a stream can erode is called

Base level

What are the three types of loads carried by streams?

Bed load, suspended load, dissolved load

Removing obstructions from a river channel is a form of a(n) ___. It can make a river more navigable, but may also increase bank erosion due to increased water flow

Channelization

As a stream's velocity decreases, which of the following sizes of sediments will be deposited last?

Clay

What type of stream is associated with the formation of an oxbow lake?

Meandering stream

What is a meander scar?

A landscape feature formed after an oxbow lake dries up

What is an oxbow lake?

A meander that has been cut off from the original stream channel

What is a stream terrace?

A remnant of an older floodplain that sits above the stream valley

Where along a meandering stream would erosion occur most intensely?

Along the outside of a bend where water moves fastest

Complete this analogy: Bouncing is to sand as suspension is to_____________.

Clay

The volume of water flowing past a certain point in a given amount of time is a river's

Discharge

Watersheds are defined by

Drainage divides

________ streams begin in moist regions and flow downstream into arid landscapes with high evapotranspiration.

Exotic

A river with a well-developed ___ has a flat low-lying channel and experiences flooding during periods of high discharge

Floodplain

The flat, broad area surrounding a stream is referred to as a(n)

Floodplain

Examples of local base level include a stream or an

Lake

Base level refers to

Level below which a stream cannot erode its valley

A sweeping bend of a stream which is migrating laterally in a wide, flat valley is called a(n) .

Meander

A stream with a low to moderate gradient, carrying most of its load in suspension, should be characterized by many curves and bends called

Meanders

A delta forms at the ___ of a river, where the velocity of the water flow decreases and deposition is highest

Mouth

In a given section of channel, the greatest flow velocities are usually

Near the surface, near the center

How many stream terraces can exist along a single valley?

No limit exists. Stream terraces will keep forming as long as lateral erosion and downcutting continue

Which of the following is not an example of humans impacting river systems?

Rivers and streams provide recreation to humans

How can pieces of rock in contact with a stream bed move?

Rolling, sliding, bouncing

The general term for channelized water flow, regardless of size, is

Stream

Are stream terraces depositional or erosional landforms?

Stream terraces can be either depositional or erosional

An ___ is the remnant of a former floodplain

Terrace