wc 13

What is a floodplain?

A broad strip of land built up by sedimentation on either side of a stream channel and covered with water during a flood

What does a hydrologic gauging station do?

Measures and records real-time data about a stream's flow

Select the conditions that caused the 1976 Big Thompson River flood near Estes Park, Colorado.

Narrow canyon Steep slopes of the river canyon Unusually severe thunderstorm

How is precipitation measured?

Rain gauges Vertical rods marked with the distance above the ground Satellites Electronic height-measuring sensors Automated Surface Observing System

At a flow velocity of 100 cm/sec, which of the following statements is true regarding sand-sized sediment?

Smaller sand grains are transported as suspended sediment, and larger grains are transported as bedload.

Isostatic rebound can change the slope of the rivers and streams flowing over the land. What is isostatic rebound?

The uplift of land that occurs after the weight of an overlying mass is removed

Which of the following describe the headwaters of mountains streams?

They have steep gradients. They have turbulent flow. They have the ability to carry large boulders,

How can the melting of an ice sheet or glacier affect a river's drainage?

Uplift of the land after the glacier melts can change drainage patterns and direction. Melting of the ice releases tremendous amounts of water and sediment that lead to new or larger channels.

Select consequences to a river when a dam is constructed.

Water released from the dam is clear (no sediment) and has a new capacity to erode and transport sediments downstream. The dam creates a temporary base level for the river. The dam causes the river to deposit its sediment load upstream of the dam.

An oxbow lake is an isolated, curved lake formed when ______.

a meander is cut off from a stream

The type of feature that forms when a steep, narrow drainage enters a broader, more gentle valley and a stream deposits the large sediments it is carrying is a(n)

alluvial fan

These are formed when a steep drainage enters a broad valley and the sediments and debris are deposited.

alluvial fans

Stream terraces are composed of either _______ or ______.

an erosional surface cut into bedrock stream-derived sediment composing former floodplains

Streams that carve directly into the rocks that compose a mountain or other area are ______ streams.

bedrock

What is stream abrasion?

breaking into chunks ?

Besides sea level and rock type, the other two primary factors that influence a stream or river's profile are ________ , and _________

climate/weather tectonics

________ drainage patterns are associated with areas where the rocks have the same resistance to erosion, whereas __________ drainage patterns are found on symmetrical mountains.

dendritic radial

The amount of water flowing through a channel over a given amount of time is called its ______.

discharge

________ meanders begin as meanders on a floodplain; either the base level drops or a tectonic event causes uplift, followed by more incision, which further deepens the meanders.

entrenched

In flowing water, the upstream side of an obstruction is subjected to the ______ of abrasion.

greatest amount

The origin of a river is called its _____, and the end of a river is called its _______.

headwaters mouth

As ice sheets melt on land, they allow for the depressed land to rise back up in a process known as ______.

isostatic rebound

Meanders, floodplains, and river terraces are commonly found along _________-gradient rivers.

low

The discharge of a river is measured in cubic _______ per second.

meters or feet

During the 1993 upper __________ River flood, floodwaters flowed onto the floodplain because levees did not hold the water back. It took months for the floodplains to dry out because the _______ trapped the water, preventing it from flowing back into the river channel.

mississippi levees

A(n) _________ stream or river is one that flows year-round, whereas a(n) ______ stream does not flow the entire year.

perennial intermittent

A depositional feature that has been built on the inside of a stream channel curve because of lower velocity is a _____

point bar

When is sediment most likely to be deposited? When the ______

sediment supply exceeds a stream's capacity to transport it

Which of the following are primary factors that influence a stream's profile?

tectonics climate rock type sea level

Sinuosity refers to ______.

the amount that a river or stream channel curves in a given length

_______ is a property of a fluid that is defined as the resistance to flow.

viscosity