8Th Grade Science Chapters 9 & 10

Front 1

water cycle

Back 1

continuous process of recycling Earth's water

Front 2

watershed

Back 2

land area drained by a stream system

Front 3

divide

Back 3

elevated land that divides one watershed, or drainage basin, from another

Front 4

stream load

Back 4

all the materials that the water in a stream carries

Front 5

flood

Back 5

potentially devasting natural occurence in which water spills over the sides of a stream's banks onto adjacent land area

Front 6

floodplain

Back 6

broad, flat, fertile area extending out from a stream's bank that is covered with water during floods

Front 7

upstream flood

Back 7

flood in small area; very sudden flood

Front 8

downstream flood

Back 8

excess water from large regional drainage system

Front 9

stream channel

Back 9

narrow pathway carved into sediment or rock by the movement of surface water

Front 10

stream banks

Back 10

ground bordering each side of a strean that keeps moving water confined

Front 11

meander

Back 11

curved or bend in a stream formed when a stream's slope decreases, water buildws up in the stream channel, and moving water erodes away the sides of the streambed

Front 12

oxbow lake

Back 12

forms when strean meander continue to develope

Front 13

lake

Back 13

natural or human--made body of water that can form when a depression on land fills with water

Front 14

alluvial fan

Back 14

forms at base of hill or mountain, is composed mainly of sand and gravel, is sloped, and flows onto dry land

Front 15

delta

Back 15

where a stream enters a quiet body of water (lake, gulf, or ocean) has deposits which consists mainly of silt and clay in firmly flat formation and forms under water

Front 16

wetland

Back 16

a land that is covered with water for a large part of the year

Front 17

infiltration

Back 17

process by which precipitation that has fallen on land surfaces enters the ground and becomes groundwater

Front 18

porosity

Back 18

percentage of open spaces between grains in a rock; is highest in well-sorted sediments

Front 19

zone of aeration

Back 19

is the area above the water table where materials are moist, but the pores mostly contain air.

Front 20

permeability

Back 20

ability of a material to let water pass through

Front 21

aquifer

Back 21

permeable underground layer through which groundwater flows relatively easily

Front 22

cave

Back 22

a natural underground opening with a connection to earth's surface

Front 23

karst topography

Back 23

irregular topography with sinkholes, sinks, and sinking streams caused by groundwater dissolution of limestone

Front 24

sinkhole

Back 24

deep depreddions in earth's surface formed when a cave collapes or be rock is dissolved by acidic rain or soil

Front 25

hard water

Back 25

water that contains high consentrations of calcium, magnesium, or iron

Front 26

soft water

Back 26

water that contains few dissolved ions

Front 27

statactites

Back 27

cone-shaped or cylinder dripstone of calcium that hands like an icicle form a cave's ceiling

Front 28

stalagmite

Back 28

mound-shaped dripstone depoist of calcium carbornate that forms on a cave's floor

Front 29

travertine

Back 29

a type of limestone found in dripstone formations

Front 30

spring

Back 30

natural discharge of ground water at Earth's surface where an aquifer and an aquiclude come in contact

Front 31

well

Back 31

deep hole drilled or dug into the ground to reach a reservoir of groundwater

Front 32

water table aquifer

Back 32

the simplest well is dug into the zone of saturation

Front 33

drawdown

Back 33

difference between the water level in a pumped well and the original water table level

Front 34

recharge

Back 34

process by which water from preciptitation and runoff is added to the zone of saturation

Front 35

artesian well

Back 35

fountain of water that spurs above the land surface when a well taps a deep, confines aquifer containing water under pressure

Front 36

subsidence

Back 36

occurs when the exessive withdrawal of groundwater causes the land to sink

Front 37

what powers the energy required for the water cycle?

Back 37

SUN

Front 38

list the 3 things that can happen to water/precipitation once it reaches Earth's surface

Back 38

1.evaporate
2.infiltration
3.runoff

Front 39

list the 4 things affecting runoff

Back 39

1.vegatation
2.rate of pricipatation
3.soil composition
4.slope

Front 40

What 2 things determine the path of streams?

Back 40

1.slope of land
2.type of material through which the stream flows

Front 41

What is the LARGEST watershed in North America?

Back 41

MS River

Front 42

list 3 ways that a stream carries its load

Back 42

1.solution
2.suspension
3.bed load

Front 43

What 2 things affect the amount of material in suspension in a stream?

Back 43

1.volume
2.velocity

Front 44

Upon what 2 things does the carrying capacity of a stream depend?

Back 44

1.velocity
2.amount of water moving in the stream

Front 45

What is the formula for streams discharge?

Back 45

.

Front 46

What is the realationship between the carrying capacity of a stream and its discharge and velocity?

Back 46

greater discharge and velocity=greater capacity of stream

Front 47

What agency is responable for the forecasting of floods?What is used to gather information about flood conditions?

Back 47

NWS (National Weather Service) and USGS (U.S. Geological Survey)

Front 48

in a straight part of a stream where is the maxamium velocity?

Back 48

center

Front 49

where is the slowest pert of velocity in a striaght stream?

Back 49

sides

Front 50

describe the 4 changes that stream undergoes as it works its way toward the ocean

Back 50

1.amount of water increases
2.velocity of water decreases
3.stream channel becomes wider
4.stream channel becomes deeper

Front 51

list the 5 wasys that lakes can form naturally.

Back 51

1.when stream flow becomes blocked by sediment from landslides
2.remnants of prehistoric lake that have receded to lower lying lakes
3.glacial lakes-kettle lake, forms (water filled cirques) moraines damned lakes
4.sink hole lakes- caverns are formed from the erosinal of limestone deposits by groundwater;roof of the cave collapse from in a sink hole filled with water
5.oxbow lakes

Front 52

what human activites affect the process of eutrophication?

Back 52

fertilizers from runoff

Front 53

what percentage of the water on Earth is fresh water?

Back 53

3%

Front 54

Where is most fresh water found?

Back 54

polar ice caps and glaciers

Front 55

what is the second most aboundant source of fresh water on Earth?

Back 55

Oceans

Front 56

What source usually replenishes groundwater

Back 56

evaporation

Front 57

what is found primarily in the zone of aeration?

Back 57

air

Front 58

where us the water table closets to Earth's surface:in the floodplain of a river, in a swamp, or on a hilltop?

Back 58

swamp

Front 59

why is the water table considered to be seasonal?

Back 59

because of it dependence on precipitation

Front 60

velocity is measured in...

Back 60

meters per second

Front 61

what 2 factors determine the flow of velocity of groundwater?

Back 61

1.slope of water table
2.permeability of the material

Front 62

aquiclude

Back 62

impermeable layer barried to groundwater flow

Front 63

what is the main characteristic of an aquifer

Back 63

ability to transport water

Front 64

what acid is most commonly present in groundwater?

Back 64

Carbonic acid

Front 65

what is the average length of time that groundwater remains underground?

Back 65

several hundred years

Front 66

of what are aquifers commonly composed?

Back 66

layers of sand, grave, sandstone, and limestone

Front 67

list the 4 situations in which springs occur.

Back 67

1.on the sides of valleys
2.at the edge of perched water table
3.along faults
4.limestone regions

Front 68

upon what does the temerature of a spring generally depend?

Back 68

the average temperature fo the regions

Front 69

hot springs

Back 69

thermal springs with temperatures higher than regular body temperature

Front 70

what happens if over pumping of a well lowers the water level in it?

Back 70

drawdown

Front 71

list 4 common sources of groundwater pollution:

Back 71

1.sewage
2.industrial waste
3.landfills
4.agricultural chemicals