Geog 106LRS - Prof. Fischer
Name __Answer key___________
Chapter 11
Self-Reflection Survey: Section 11.1
1. What river is nearest to where you live? Where
does the river begin and end?
border. Draw the approximate position of the drainage
divide for the Missouri and Mississippi basins in Iowa
on the map provided here.
answers vary
2. How do people interact with streams in your
community? (Think recreation, biology,
economics, politics, history, aesthetics, etc.)
answers vary
3. List at least three rivers that act as boundaries for
U.S. states and the states that they separate.
answers vary
4. List at least three major rivers around the world
(not described in the text) that start in one country
and end in another (and the starting and ending
countries).
Checkpoint 11.7 Draw the approximate boundaries
of the drainage basins for the named streams. Note
that the Savannah and St. Marys Rivers mark parts of
the boundary of the state. Do not include the
Savannah or St. Marys Rivers’ drainage basins.
answers vary
Checkpoint 11.1
Sort the following twelve terms into six pairs of terms
that most closely relate to one another.
groundwater-infiltration;
rainfall-precipitation;
ice-melt water;
stream-runoff;
gas-water vapor;
plants-transpiration
Checkpoint 11.2 Imagine that it rained
continuously all over the world for a month. If we
were to measure the depth of the oceans over a 5-day
period near the end of the month, what would we
observe? Explain your choice referring to the
different parts of the hydrologic cycle.
a) Ocean depths rise steadily
b) Ocean depths fall steadily
c) Ocean depths stay the same
Rain water is primarily evaporated ocean water.
Checkpoint 11.6 Rivers in Iowa flow to either the
Mississippi River, which makes up the eastern state
border, or the Missouri River on the western state
Skim section 11.4. How is stream velocity
different from stream discharge?
Velocity is how fast (e.g., mph) a leaf would float
downstream. Discharge is the volume of water
moving past a point in a give time (e.g., cubic feet
per second).
Checkpoint 11.13 What statement is most likely
true about a pebble found in a stream?
a) It formed from erosion of sedimentary rock in the
stream bed or bank.
b) It formed when sand and clay clumped together in
the stream.
c) It is younger in age than the stream channel.
d) It may be composed of any type of rock.
Checkpoint 11.14 Consider the consequences of
constructing a dam on a river that has a large stream
load, such as the Yellow River. Assume the dam and
its reservoir are located about two-thirds of the way
down the river. How would stream flow conditions be
altered above and below the dam and its reservoir?
What would be the implications for erosion, transport,
and deposition?
This is a synthesis-level question that requires
students to merge several aspects of stream
dynamics in an actual scenario. Good student
response will discuss how and why deposition will
occur in the reservoir behind the dam and how
this will substantially reduce the load along the
downstream section of the stream. Less
transported load will result in more erosion
downstream from the dam, deepening and
widening the stream channel. The most perceptive
students may point out that this should reduce the
opportunity for floods in the short term.
E
D
D
D
E
D
E
E
Checkpoint 11.15 Image Analysis: Mississippi
River Radar Image
Examine the accompanying image of part of the
lower course of the Mississippi River. The river flows
from north to south (top right to bottom left).
2. Identify where erosion and deposition are occurring
along the stream channel, and label those locations E
(erosion) and D (deposition) on the blank map to the
left of the image (think point bar and cut bank).
3. Use the blank map to draw an earlier course of the
channel.
Checkpoint 11.16
Create a concept map that links together the
components of erosion, transportation, and deposition
in a stream channel. Include stream discharge, stream
velocity, and stream gradient.
This is an open-ended synthesis-level exercise.
Good student concept maps will include ideas such
as cut banks, point bars, dissolved load, suspended
load, bed load, stream velocity, and gradient. Poor
student responses will simply show concepts
related to cut banks and point bars.
Checkpoint 11.17
List five factors that influence flooding. Use one
sentence to briefly describe the role of
each factor in flooding.
Appropriate terms include precipitation, slope,
snowmelt, urban development, run off, vegetation,
flood control.
Checkpoint 11.18
Four stream gauging station locations (A, B, C, D) are
shown on the accompanying map. Assuming that the
bedrock and topography are similar for each stream
system, predict which station will record the greatest
discharge. a) A b) B c) C d) D
Why? Largest watershed above gage
Checkpoint 11.22 Flood Control Defining
Features Matrix
Complete the following table by placing check marks
in the appropriate columns to identify whether the
characteristics listed at the left represent prevention or
adjustment measures for flooding. One characteristic
has been completed as an example.
Characteristic
Preven Adjustme
tion
nt
X
X
Levee is constructed
Newspaper publishes flood evacuation
route
New housing developments are elevated
on pilings above ground
Dredging removes sediment from
X
streams
Flood zone maps are made available in
local library
Buildings are relocated outside of flood
zone
Dam is constructed upstream from
X
community
Zoning regulations are enacted to prevent
new construction in floodplain
X
X
X
X
End of chapter Concept Map
Complete the following concept map to evaluate
your understanding of the interactions between
the Earth system and streams and floods. Label
as many interactions as you can, using
information from this chapter (especially
underlined ones).
A
Rainfall over the ocean
B
Evaporation from oceans to atmosphere
C
Artificial surfaces increase flow to streams
D
Wetlands absorb floodwaters
E
F
G
H
I
Friction from stream bed and channel on water
in stream
J
Deposition of sediment when stream velocity
decreases
K
Transpiration of plants
L