Lesson 9 Flashcards
What describes the continuous interchange of water among the oceans, atmosphere, and continents?
hydrologic cycle
What illustrates the circulation of Earth’s water supply?
hydrologic cycle
What is a global system in which the atmosphere provides the link between the oceans and continents?
hydrologic cycle
What powers the hydrologic cycle?
the sun
What is the movement of water into rocks or soil through cracks and pore spaces?
infiltration
When water flows over the land, rather than infiltrating into the ground?
runoff
What is the release of water vapor to the atmosphere by plants?
transpiration
The processes involved in the water cycle include
precipitation evaporation infiltration runoff transpiration
What is water released from clouds in the form of rain, freezing rain, sleet, snow, or hail?
precipitation
What is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase?
evaporation
Is the hydrologic cycle balanced?
yes
What are the factors that determine a stream’s velocity?
gradient
channel characteristics
streams discharge
What factors increase downstream?
width
depth
discharge
velocity
What is the amount of water passing a given point per unit of time, frequently measured in cubic feet per second?
streams discharge
What is the slope of the stream channel?
gradient
What are the channel characteristics?
shape
size
roughness of channel
What factors decrease downstream?
gradient
roughness of a stream
What does the profile of a stream look like?a smooth curve?
a smooth curve
What are the factors that increase downstream?
Velocity
Discharge
Channel size
What are the factors that decrease downstream?
Gradient, or slope
Channel roughness
What are the two profiles of streams?
Cross-sectional view
From head to mouth
What is the head of the stream known as?
the source
Gradient (increases/decreases) from the head to the mouth.
decreases
What are the two general types of base level?
ultimate
temporary or local
What is the lowest point a stream can erode to called?
base level
Any change in base level will cause a stream to ____ and establish a new ______.
adjust
balance
Lowering base level will cause a stream to ______.
Raising base level results in ______ of material in the channel.
downcut
deposition
What can occur from the work of a stream?
erosion
transportation
deposition
What is a streams erosion?
the incorporation of material
What are examples of a streams transportation?
dissolved load
suspended load
bed load
What are the types of load?
dissolved load
suspended load
bed load
Load is related to a stream’s?
Competence
Capacity
What is a steam’s competence?
What is it determined by?
Maximum particle size
Velocity
What is a streams capacity?
What is it related to?
Maximum load
discharge
What are stream sediments called alluvium?
Well-sorted deposits
What is deposition caused by?
decrease in velocity
When velocity decreases, what happens to competence and sediment?
competence is reduce
sediment drops out
What are stream sediments called?
alluvium
What are the features produced by deposition?
deltas
natural levees
Were do distributaries of deltas often form?
in the channel
Where do deltas exists?
oceans
lakes
Where do natural levees form?
parallel to the stream channel
What might the area behind the levees contain?
Back swamps
Yazoo tributaries
What are valley sides shaped by?
Weathering
Overland flow
Mass wasting
What are the two general types of stream valleys?
narrow
wide
What type of stream valley has a flat floor?
wide valleys
What shape are narrow valleys?
v-shaped
Which type of stream valley has more dominant down-cutting or erosion toward the bottom of the floor?
narrow valleys
What are two types of features at narrow valleys?
rapids
waterfalls
Wide valley streams have their stream near _____ level
making the stream energy directed from ______
base
side to side
What is the flat floor from erosion in wide valley called?
floodplains
Which stream valley has its energy is directed from side to side?
wide valley
What are some features of floodplains?
Meanders
Cutoffs
Oxbow lakes
What does widespread meandering cause?
cutoffs
oxbow lakes
What is the name of movement of a stream in sweeping bends?
meanders
What is the nae of shorter channel segments?
cutoffs
What is the name of abandoned bends?
oxbow lakes
What is the most common geologic hazard?
floods
What are the causes of floods?
weather
human interference with the stream system
Many scientists and engineers advocate a nonstructural approach to flood control that involves more appropriate _____.
land use
What are some examples of floods caused by weather?
heavy rains and/or snowmelt
What are some engineering efforts to provide flood control?
Artificial levees
Flood-control dams
Channelization
What are the types of drainage patterns?
Dendritic
Radial
Rectangular
Trellis
What is the land area that contributes water to a stream called?
drainage basin
What is the imaginary line separating the drainage basin called?
divide
What are drainage basins separated by?
an imaginary line
