Surface Water Study Guide

Name:

Modified True/False

Indicate whether the sentence or statement is true or false. If false, change the identified word or phrase to make the sentence or statement true.

Some runoff initially flows in thin sheets and eventually collects in miniature channels called rills and brooks. _________________________

There is a greater potential for erosion on shallow slopes. _________________________

When water runs through or over rocks containing soluble minerals, it dissolves small amounts of the minerals and carries them away in solution. _________________________

Both water velocity and volume increase during times of heavy precipitation. _________________________

During rejuvenation, the stream actively resumes the process of downcutting toward its bed. _________________________

Lakes can be common in areas where limestone is the dominant bedrock. _________________________

When huge numbers of plants and animals decay, a lake’s phosphate supply is depleted. _________________________

A major source of algae-supporting nutrients that concentrate in lakes is phosphate detergents. _________________________

Stream banks have historically enticed farmers to use the land for crop production, even at the risk of losing crops to flooding. _________________________

10.

In a stream, small particles, such as silt, clay, and sand are carried in solution. _________________________

11.

Deltas are fan-shaped deposits found on valley floors at the base of mountains. _________________________

12.

Heavy accumulations of excess water from large regional drainage systems can result in downstream floods. _________________________

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

13.

The three ways in which a stream carries its load are in solution, suspension, and ____.

a.	stream velocity	c.	bed load
b.	stream channel	d.	channel capacity

14.

Which of the following is the formula for discharge?

a.	discharge = width ´ depth ´ velocity
b.	discharge = stream load ´ depth ´ velocity
c.	discharge = stream load ´ friction ´ velocity
d.	discharge = width ´ depth ´ velocity ´ friction

15.

In order for rejuvenation to take place in a stream, what must occur first?

a.	Deposition must stop.
b.	The stream must dry up.
c.	The land over which the stream flows uplifts.
d.	The discharge must increase.

16.

Which of the following statements is true about the development of a stream?

a.	A stream’s slope increases as it approaches base level.
b.	Water along the sides and bottom of the channel flows more rapidly.
c.	Deposition is greater in the outside curve of a meander.
d.	The velocity of water is greater along the outside of a meander curve.

17.

The eutrophication of a lake leads to ____.

a.	the formation of a bog
b.	the decay of dead plants and animals
c.	the death of all life in the lake
d.	fertilizers from farmers fields being picked up by the lake

18.

Potholes form in the stream bottom when ____.

a.	the water dissolves the bedrock
b.	turbulence causes pebbles to swirl
c.	an increase in suspended load occurs
d.	the stream’s carrying capacity decreases

19.

The carrying capacity of a stream is its ____.

a.	ability to transport sediment	c.	volume of flow
b.	rate of runoff entering the channel	d.	stream bank height

20.

Streams lengthen through ____.

a.	eutrophication	c.	headward erosion
b.	suspension	d.	upstream flooding

21.

V-shaped channels like the Grand Canyon are formed by ____.

a.	a sudden decrease in stream gradient	c.	streams overflowing their banks
b.	stream downcutting	d.	streams capturing another stream

22.

A blocked-off meander eventually becomes ____.

a.	part of the stream again	c.	an oxbow lake
b.	rejuvenated	d.	an alluvial fan

23.

Which of the following statements is NOT true about wetlands?

a.	Wetlands result from the eutrophication of a lake.
b.	Lack of oxygen and lack of minerals create an atmosphere that is inhospitable to many plants.
c.	Freshwater marshes often form along the stream’s mouth and in areas with deltas.
d.	Wetlands only exist in freshwater areas.

Completion

Complete each sentence or statement.

24.

Water that flows downslope along Earth’s surface is called ____________________.

25.

A stream has a(n) ____________________, which is the land area whose water drains into the stream’s system.

26.

Any high land area that separates one watershed from another is termed a(n) ____________________.

27.

Material is carried in ____________________ after it becomes dissolved in a stream’s water.

28.

All particles small enough to be held up by the turbulence of a stream’s moving water are carried in ____________________.

29.

A stream’s ____________________ consists of all sand, pebbles, and cobbles that the stream’s water can roll or push along the bed of the stream.

30.

____________________ is the total volume of stream water that flows over a particular location within a given period of time.

31.

Flowing surface water carves a(n) _________________________, or a narrow pathway, into rock.

Matching

Match each item with the correct definition below.

a.	rejuvenation	e.	meander
b.	lake	f.	delta
c.	stream banks	g.	wetland
d.	flood

32.

The ground that borders a stream and holds the water within the confines of the channel

33.

A bend or curve in a stream channel

34.

A triangular deposit that forms where a stream enters a large body of water

35.

A stream resumes the process of downcutting

36.

A depression in the land that holds water

37.

An area periodically saturated with water

38.

Water spills over the sides of a stream’s banks

Short Answer

39.

Compare and contrast materials carried in suspension and solution by the stream.

40.

Identify the two stream formations shown below. Compare how each is formed.

41.

Describe three processes of lake formation.

42.

Explain how people have contributed to the destruction of wetlands.

43.

Explain how floodplains develop such highly fertile soils.

44.

Compare downstream and upstream flooding.

45.

What factors increase or decrease the amount of runoff in an area?

46.

In the diagram below, a section of a meandering stream is shown. What occurs at the areas labeled A and B?

47.

Describe what causes a stream to stop downcutting its bed and what causes it to start again.

48.

Compare the velocity of water, the erosion, and the deposition along the inside and outside of a meander curve.

49.

Describe three ways a natural lake can form.

50.

How does an increase in a stream’s velocity affect its discharge and carrying capacity?

51.

How do vegetation and slope affect runoff?

The graph shows the discharge of a river that flows through two cities, Frankston and Wet Gulch. At either city, the river’s banks cannot handle a discharge of 3.5 million cubic meters per second or more. At that point, the river reaches its flood stage. Study the graph and answer the questions.

52.

During how many days in March did the river at Wet Gulch and Frankston overflow its banks?

53.

Wet Gulch is downstream from Frankston. How might this account for the difference in discharge between the two towns after March 10?

54.

Both cities were founded as farming communities during the 1800s on the floodplain. Describe the physical features of a floodplain, and hypothesize as to why people wanted to live on them.

Problem

The table lists water quality measurements that were taken over a 40-year period at Lake Smith. Measurements included dissolved oxygen, pH, phosphate, nitrogen, the number of largemouth bass, and mosses and grasses. Dissolved oxygen is the measure of the amount of oxygen available to life-forms in the water. Largemouth bass is a common variety of fish found in healthy lakes. Mosses and grasses start to appear as the pH of the water becomes more acidic.

Water Quality at Lake Smith
	1950	1955	1960	1965	1970	1975	1980	1985	1990
Dissolved oxygen (parts per million, or ppm)	20	19	18	18	16	17	15	11	9
pH	7.6	7.2	7.1	7.0	6.8	6.8	6.5	6.1	5.8
Phosphate (ppm)	0.0	0.10	0.20	0.25	0.28	0.28	0.45	0.55	0.55
Nitrogen (ppm)	0.05	0.18	0.19	0.25	0.28	0.28	0.35	0.40	0.45
Largemouth bass	450	455	448	338	235	220	155	125	50
Mosses and grasses	0	0	2	5	15	18	29	35	55

55.

What is eutrophication? Did it occur at Lake Smith? Explain your answer.

56.

After 1950, farmers in the Lake Smith area increased their use of fertilizers. Does the data support this statement? Explain your answer.

57.

How do changes in phosphate and dissolved oxygen content over time compare? Explain the changes that took place.

58.

What do you predict will happen to the lake in the next 40 years?

59.

The table shows that the number of largemouth bass decreased as the number of mosses and grasses increased. From this data, can you conclude that the increase of mosses and grasses caused the largemouth bass population to decline? Explain your answer.