Geology Quiz 16

A dam and reservoir are constructed on a graded river. What will happen?
deposition upstream from the dam; channel downcutting below
The ________ describes the movement of water through Earth's hydrosphere.
hydrologic cycle
Which one of the following statements is true concerning natural levees?
mostly fine sand and silt that build up during floods
For a meandering stream, the majority of erosion occurs _____.
at the outside of a bend
Depositional landforms are created where energy of the stream __________.
has decreased
________ make up the suspended loads of most rivers and streams.
Silt and clay-sized detrital grains
Which of the following is the correct definition of stream gradient?
the drop in elevation of a stream divided by the distance the water travels
The lowest base level for most streams is sea level.
The term used by geologists for all water flowing in a channel is _____.
Stream discharge is defined as the quantity of water flowing past a specific channel location per unit time.
Natural levees are constructed of machine-compacted sand and mud; artificial levees are made of concrete.
What is a floodplain?
a flat surface next to a river channel
What is a natural levee?
a ridge of flood deposits next to a river channel
How does the formation of a natural levee impact flooding?
Natural levees raise the height of the stream channel, reducing the amount of flooding that will occur on the floodplain.
Point bars are depositional features located along the outer portions of meander bends.
________ is an abandoned, cutoff, meander loop.
An oxbow
How does urbanization (paving, etc.) affect runoff and infiltration in a small, previously forested, drainage basin?
infiltration decreases; runoff increases
________ are components of the hydrologic cycle that release water vapor directly to the atmosphere.
Evaporation and transpiration
What is the drop in water surface elevation divided by the distance the water flows?
stream gradient
Gradients usually decrease downstream in a major river system.
Where is erosion concentrated along a meandering stream?
on the outer parts of the meander loops or bends