Ground water

Question 1

Groundwater

Answer 1

water below the Earth’s surface that fills voids in soils and rocks

Question 2

Groundwater comprises __% of the water on earth

Answer 2

1%

Question 3

Recharge

Answer 3

occurs when water enters into the subsurface and becomes groundwater by percolating into soil or rock at the surface

Question 4

Groundwater recharge cycle

Answer 4

1. Rainwater or snowmelt seeps into the ground
2. Gravity moves water downward through the zone of aeration until it reaches the water table
3. Flowpaths of water past water table lead to rivers

Question 5

A spring will emerge where the water table intersects ____.

Answer 5

the surface

Question 6

Zones of groundwater

Answer 6

Vadose (aeration, unsaturated), and saturated zone

Question 7

Vadose and saturated zones are separated by the

Answer 7

water table

Question 8

Vadose zone

Answer 8

the region nearer to the surface where pores or fractures in the subsurface are not entirely filled with water.

Question 9

Posority

Answer 9

the amount of pore space in a geologic medium such as soil, sediment, or rock between 0 and 100%

Question 10

Permeability

Answer 10

a measure of the ease with which a fluid can flow through a geologic medium.

Question 11

Permeability is related to:

Answer 11

porosity and connectedness of pores

Question 12

Clay permeability

Answer 12

Clay has high porosity but pores are small and poorly connected, so clay has low permeability

Question 13

The water table is a subdued imitation of the ____.

Answer 13

landscape

Question 14

the water table ____ under hills and ____ under valleys

Answer 14

rises

lowers

Question 15

Relationship between the water table and the season

Answer 15

The water table will raise/lower depending on the seasons. During rain events and spring melt, the water table will rise.

Question 16

What controls the exact position of the water table in the subsurface

Answer 16

the physical properties of the porous medium

Question 17

Surface expressions of the water table

Answer 17

surface water bodies (rivers, lakes, and ponds)

Question 18

What drives groundwater flow

Answer 18

gravity

Question 19

Groundwater flows from regions of ___ pressure to regions of ___ pressure

Answer 19

from high pressure to low pressure

Question 20

Hydraulic head

Answer 20

A measure of the pressure difference that drives groundwater flow.

Question 21

Groundwater flow follows _____ paths.

Answer 21

curving

Question 22

Groundwater flows from ___ areas to ____ areas.

Answer 22

recharge (infiltration) to discharge (rivers)

Question 23

Discharge

Answer 23

A region where groundwater emerges at the surface

Question 24

Examples of discharge areas

Answer 24

rivers, lakes, streams, wetlands

Question 25

Springs

Answer 25

natural points of groundwater discharge that occur when the water table or permeability boundary intersects at the land surface

Question 26

Aquifer

Answer 26

units of geological media that have sufficient capacity and high enough permeability to supply water at a rate useful to humans.

Question 27

Two types of aquifers

Answer 27

Unconfined aquifer, confined aquifer

Question 28

Unconfied aquifer

Answer 28

an aquifer in which the upper boundary is defined by the water table

Question 29

Confined aquifer

Answer 29

an aquifer in which the upper boundary is defined by an aquiclude (geological media that stops the flow of media)

Question 30

Aquiclude

Answer 30

units of geological media that have considerably slow flow or completely stop the flow of water (has low permeability) - usually have an impermeable rock layer on top

Question 31

Cone of depression in the water table surrounding a well

Answer 31

occurs when the rate of groundwater withdrawal (pumping) exceeds the rate of local groundwater flow at a well

Question 32

Groundwater causes the transportation of mass through the ___ and ___ of minerals in geologic media

Answer 32

dissolution and precipitation

Question 33

Dissolution of minerals depends on

Answer 33

groundwater chemistry - groundwater pH

Question 34

Precipitation of minerals occurs when

Answer 34

ions dissolve in groundwater come out of solution due to changes in factors such as pH, pressure, or evaporation

Question 35

Stalactites

Answer 35

Rocks hanging from the ceiling

Question 36

Stalagmites

Answer 36

rocks growing from the floor

Question 37

How stalacites and stalagmites form

Answer 37

dissolved ions in groundwater precipitate to form rocks in caves due to evaporation and other changes in groundwater chemistry.

Question 38

Cement

Answer 38

Mineral deposits in small pore spaces

Question 39

Cement may convert loose sand into

Answer 39

sandstone

Question 40

Cement may convert an aquifer into an

Answer 40

aquiclude

Question 41

Cement may make a potential oil reservoir into a

Answer 41

non-porous non-reservoir