1/7/24 EARTH SCIENCE UNIT 4 EXAM Flashcards
Erosion
the movement of weathered material
what moves sediment the most?
running water moves sediment more than any other type of erosion
what happens when precipitation falls to Earth’s surface?
some evaporate, some infiltrate into the ground and becomes ground water, and some becomes runoff
accumulation
the process in which water pools into large bodies of water (like oceans, seas, and lakes)
condensation
the process in which water vapor (a gas) in the air turns into liquid water. Condensing water forms clouds in the sky. Water drops that form on the outside of a glass of icy water are condensed water
evaporation
the process in which liquid water becomes water vapor (a gas)
precipitation
the process in which water (in the form of rain, snow, sleet or hail) falls from clouds in the sky
surface runoff
rain, snowmelt, or other water that flows in surface streams, rivers, or canals
subsurface runoff
rain, snow, melt, or other water that flows in underground streams
transpiration
the process in which some water within plants evaporates into the atmosphere, water is first absorbed by the plant’s roots then later exits by evaporating through pores in the plant
what do ground conditions determine?
ground conditions determine whether precipitation becomes runoff or groundwater
ground conditions:
1) saturated vs. unsaturated 2) vegetated vs. non vegetated 3) gradient
what happens when runoff becomes confined to a channel?
when runoff becomes confined to a channel a stream exits
what are the factors that affect stream/river velocity?
1) gradient 2) stream discharge (the amount of water in the channel) 3) stream channel shape
What is gradient?
Gradient refers to the slope of the land
what happens when gradient increases?
when gradient increases, variety increases
what happens when discharge increases?
when discharge increases, velocity increases
Why is velocity the fastest in the middle of a straight channel?
Velocity is the fastest in the middle of a straight channel because the water is forced to slow down due to friction encountered all along the channel
Where is velocity fastest and slowest in a stream meander? and why?
In a stream meander, velocity is fastest on the outside bend and velocity is slowest along the inside bend. This is because water flows straight downhill until it hits something that forces it to change direction, this causes the fastest eater to impact the outside bend stronger
Where does erosion occur in a stream meander?
water moves faster along the outside bend of a meander, erosion will occur here
cutbanks
erosion on the outside bend of a meander causes it to cut away at the bank
meander
a bend in a river channel, formed when water in the river erodes the bank of the outside of the channel
where does deposition occur in a meander?
water moves slower along the inside bend of a meander, deposition will occur here because when water slows down it drops heavier sediment it no longer can carry. this is a point bar
where does erosion occur in a meander?
the outside bend of a meander is here more erosion occurs because faster velocity, this is a cutbank
