GEOS 1111L MG 12 Streams

Look at the topographical map below. Which elevations of the Flint River would cause the Montezuma Post Office to be flooded? Note: The contour interval for this map is 10 foot.

-290 ft -300 ft The post office must have an elevation between 280 and 290 feet. River elevations greater than this will potentially flood the post office.

Create a trace report to determine how many states are part of the Mississippi River watershed. Determine which of the rivers below are tributaries of the Mississippi River. Select the three that apply.

-Arkansas River -Yellowstone River -Ohio River

Where could oxbow lakes form in the future?

-B -C -D

Take a moment to think about how the Colorado River has evolved through time. Focus on how changing base level and stream incision created landforms, such as incised meanders and rincons, and arrange these events accordingly. Rank from oldest to youngest.

-Oldest Event- 1. A stream migrates laterally across its floodplain developing meanders. This stream terminates at a lake, which is its base level. 2. The base level of the stream is lowered by crustal uplift and the river begins to incise downward. 3. Incised meanders form. 4. A rincon forms by the cutoff of an incised meander, which shortens the river. -Youngest Event-

The water discharge of which of the following cities would have an impact on the water quality in New Orleans? Select the four that apply.

-Pittsburgh, PA -Chicago, IL -Denver, CO -Minneapolis, MN Over 12,000 cities are located along the Mississippi River and its tributaries!

Which of the following statements are true about the inside of a meander curve? Check all that apply.

-Referred to as the point bar -Deposition occurs at this location

Which of the following characteristics or features describe the headwaters of a stream? Select the two that apply.

-erosion dominates -high elevation and slope/gradient

What is the probability (as a percentage) of a 500-year flood occurring in any given year?

0.2%

What is the sinuosity of a stream that has a straight line distance of 2.5 miles and a stream channel length of 4 miles?

1.6

A stream is flowing down a slope into a larger river. The elevation of the head of the stream is 1,776 feet above sea level. The elevation of the mouth of the stream is 1,298 feet. The distance between those two points is 15,098 feet. What is the gradient of the slope the stream is flowing over in ft/mi?

167 ft/mi

Which of the placemarks in the Stream Order folder is labeled with the most accurate stream order number?

2

How many oxbow lakes are present in this image?

3 Oxbow lakes can disappear over time as sediment fills the abandoned channel and water no longer enters the depression.

How many states are part of the Mississippi River watershed?

31

What order stream is the stream at Point B?

3rd The stream at Point B is a third-order stream.

What is the gradient of the stream from Point A to Point B?The elevation of Point A is 2460 ft above sea level and the elevation of Point B is 2380 ft above sea level. The two points are 2 miles apart.

40 feet/mile

What is the stream gradient of the Arkansas River between the two placemarks in the Stream Gradient folder?

7.22 meters/kilometer

Which of the placemarks in the Stream Channel Patterns folder best resembles a braided stream pattern?

A

The following photo shows a typical cut bank on the Missouri River (iPhone for scale). Note the steep profile with fine-grained sediments above coarser sands and gravels.

A cut bank is located on the outside of a meander bend. Cut banks are located on the outside of meanders and are dominated by erosive processes. Look at the unstable overhanging portion of the bank in both photos. With continued undercutting by the stream during flood stage, this part of the cut bank will eventually collapse and be carried away by the stream.

The Goosenecks of the San Juan River are located in southeast Utah. At this location, the San Juan River has cut a gorge through at least 1,000 feet (300 m) of Paleozoic sedimentary rocks. As mentioned in the video, this region was affected by uplift of the Colorado Plateau during the Cenozoic era. Base level was lowered and this river began to incise downward due to a steepened gradient. A raft on the San Juan would float more than 6 miles to match a crow flying straight for 1.5 miles above this landscape. The Google Earth image and photo below, which depict the same location from different angles, show two features, labeled A and B, that were created by downcutting of the San Juan River. Choose the correct pair of terms from the choices below.

A) incised meanders B) terraces Uplift of the Colorado Plateau has caused the base level to be lowered. The river has adjusted to the increase in gradient by downcutting through several hundred feet of sedimentary rocks, while maintaining a meandering course. The images show incised meanders and terraces, which are labeled A and B, respectively.

Which statement defines stream terrace?

Abandoned floodplains

Which of the placemarks in the Stream Types folder represents an ephemeral stream?

B

Which of the placemarks in the Stream Drainage Patterns folder represents a radial drainage pattern?

C

Which line contained in the Drainage Divide folder best represents a drainage divide?

D

Which of the labeled placemarks in the Floodplain Landforms folder would have the highest active rate of deposition?

D

Which of the following placemarked locations in the Davis' Geomorphic Cycle folder best illustrates Davis' idea of an old age landscape?

E

Label the features associated with meandering streams on the diagram below. Drag the appropriate labels to their respective targets.

Escarpment Terrace Floodplain Cut Bank Levee (in order, top to bottom, left to right)

Below is a photo from the meandering channels at Missouri Headwaters State Park, in southwest Montana. At this location, the Missouri River is formed at the confluence of the Gallatin, Madison, and Jefferson Rivers. This river flows 2,341 miles before joining the Mississippi River, and is considered the longest river in the United States. Different processes influence the lateral migration of a meandering channel in its valley. Erosion, transport, and deposition all play significant roles in shaping a river through time. Focus on the locations in the channel where velocity is fast and slow, where along the channel erosion and deposition is occurring, and which direction the channel will migrate through time.

From Left to right erosion faster water velocity direction of channel migration:<-- (left arrow) slower velocity deposition You can see the steep eroded cut bank on the left side of the photo and the gently-sloping point bar on the right. The velocity of the water is faster along the cut bank, leading to erosion of this feature. The opposite is true for the point bar. As erosion and deposition continue through time, this meandering channel will migrate toward the left.

A flood plain is the flat area around the river extending from its channel to the edge of the wide valley. Drag the appropriate labels to their respective targets. Not all labels will be used.

From Left to right: point bar scroll bars cut bank floodplains

In how many named streams does the water flow to this point in the stream? Stream Names (count): ___________Note that you can see a list of these streams by clicking on "Stream Names" in the report.What is the total length of the named streams? Total Length of Traced U.S. Streams (miles): ________________

Stream Names (Count): 1,042Total Length of Traced U.S. Streams (miles): 36,775

In how many named streams does the water flow downstream from this point? Stream Names (count): ___________Through how many communities does the water flow downstream from this point? Cities (count): ______________

Stream Names (count): 6Cities (miles): 127

If the last 100-year flood occurred in a region in the current year, when is the next 100-year flood possible?

The same year Multiple 100-year floods can occur (and have occurred) in a given location in the same year.

La Cañada Alamosa is a tributary of the Rio Grande, located in central New Mexico. Due to climatic changes, the local base level for this stream was lowered. This occurred many times as evident by the presence of multiple terraces. Rounded gravels present on the terraces represent former channel deposits. Using the following photos, classify the observations according to whether they are "true," or " false."

True: -At least two episodes of downcutting have occurred. -Rounded gravels provide evidence that these fault-topped features are terraces. False: -The local base level for this stream is sea level. -Only one terrace is present at La Canada Alamosa

The lowest level to which a stream can erode is called _______.

base layer

Which stream channel type is visible in this figure?

braided stream

If the velocity of a stream decreases, competence __________ and sediment is _____.

decreases, deposited

A __________ defines the area of land that will supply water to a stream.

drainage basin

Incised meanders and terraces are __________.

erosional features

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

floodplain

Velocity and turbulence are _____ at the __________.

greatest; outside of a meander

A(n) _______ is a bend in a steep narrow bedrock valley.

incised meander

Examples of a local base level include a stream or a(n) _______.

lake

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

meander

Which stream drainage pattern would consist of a central high elevation region with several streams draining away from it in all compass directions?

radial

A(n) ______ is the remnant of a former floodplain

terrace