Groundwater

Question 1

Groundwater

Answer 1

drinking water
Irrigation
Industry

Question 2

Infiltration

Answer 2

rain enters the subsurface depending on soil and vegetation
Soil can wick or evaporate it

Question 3

groundwater

Answer 3

water in subsurface void {pore} spaces

Question 4

Porosity

Answer 4

Open spaces in sediment
Total volume Of water that fits
Primary and secondary

Question 5

Primary porosity

Answer 5

Formed in material originally
Vesicles in basalt {gas bubble}

Question 6

primary porosity shrinking

Answer 6

burial compaction
Cementation
Crystalline rocks have small porosity

Question 7

Secondary porosity

Answer 7

fracturing, faulting dissolving- creates spaces later on

Question 8

Permeability

Answer 8

ease of water flow
Depending on pore connection
Enchanted by large, straight flows

Question 9

aquifers

Answer 9

sediment that is highly permeable (water passes easily)

Question 10

aquitards

Answer 10

sediment that slows water flow (low permeability)

Question 11

unconfined aquifer

Answer 11

aquifer that touches the surface and atmosphere , others are underneath (confined)

Question 12

Water table

Answer 12

subsurface boundary (topmost) ——>
Above -> airy pores (vadose/ unsaturated zones)
Capillaries are in between, moisture wicked upward
Below -> water-filled pores
(Phreatic, saturated zone)

Question 13

capillary wicking

Answer 13

The pores allow water to be absorbed upward into it like a paper towel soaking in water

Question 14

water table depth

Answer 14

humid= close to surface
Dry = 10-100 meters down

Question 15

water table exposure

Answer 15

perennial surface water (streams, lakes, ponds, wetlands) does the exposing

Question 16

Vadose- unsaturated zones

Answer 16

zone of airy pores

Question 17

phreatic (saturated zone)

Answer 17

water-filled pores

Question 18

Water table position

Answer 18

Rises with rainfall
Falls with drought
Ponds dry up

Question 19

table topography and elevation

Answer 19

mimics topography on top
Land is high-> table high
Land is low-> table low
Alwyas flows from high to low

Question 20

Perched water table

Answer 20

discontinuous aquitards in the subsurface
(Water table is below subsurface)
Stop downward seeping into actual water table
Easily dewatered

Question 21

GW flow

Answer 21

vadose (unsaturated zone)= Flows straight down (gravity)
Phreatic (saturated zone)= flow of gravity AND pressure

Question 22

GW flow- hydraulic head

Answer 22

potential energy flow
Due to elevation above sea level (highest point for beginning)
Pressure from weight of water above

Question 23

GW flow- hydraulic head

Answer 23

moves from high to low hydraulic head (water table high and low)

Question 24

GW flow PATH

Answer 24

curved towards or upwards body of water / lower hydraulic head
(Stream sunken between drainage divides)

Question 25

Groundwater infiltration towards the path

Answer 25

Comes in through recharge areas where it goes directly downwards (high ground with rain) Exits upwards into body of water (discharge area)

Question 26

Flow scales

Answer 26

local- shallow over short time and distance Intermediate- moderate flow Regional - deep, long distance and duration

Question 27

flow rates

Answer 27

Slow Friction and electrostatic forces Ocean currents- 3 km/hr Steep river channel - 30km/hr Groundwater- 0.00002 km/hr

Question 28

flow rate factors

Answer 28

High Permeability- increased rate Hydraulic gradient- head changes horizontally-> steeper= faster

Question 29

Darcy’s law

Answer 29

Volume passing through aquifer = discharge volume = hydraulic gradient X permeability

Question 30

hydraulic conductivity

Answer 30

a material’s Ability to transmit water through pores Easy in sand and gravel Low in clay

Question 31

tapping GW

Answer 31

wells- excavated holes Springs- natural outlets

Question 32

Wells

Answer 32

dig into saturated zone