EV1005 - L9 Groundwater Resources

Question 1

How much of earths surface is covered by water? (%)

Answer 1

75%

Question 2

How much of the human body is made up of water? (%)

Answer 2

65%

Question 3

Of all the fresh water on earth, where is most of it? (2) and how much is easily accessible? (1)

Answer 3

Water is held in ground water (30.8%) and ice (68.9%). Rivers and lakes only make up 0.3% of fresh water resources

Question 4

What amount of m^3 available per capita defines the area to be water STRESSED?

Answer 4

1700m^3 available per capita

Question 5

What amount of m^3 available per capita defines an area to be water SCARCE?

Answer 5

1000m^3 available per capita

Question 6

True of False? Water sources are often close by to large populations

Answer 6

False. For example, nearly 50% of the worlds lakes are at high altitudes in Canada

Question 7

How much of the world’s population lives in countries that are water stressed? (/)

Answer 7

Approx one third (33%)

Question 8

Where does the majority of fresh water get used?

Answer 8

Agriculture uses aprox 70 times more water that what is used for drinking water and other domestic purposes

Question 9

According to UNESCO in 2000, agriculture accounted for what percentage of fresh water use?

Answer 9

Approx 67%

Question 10

How is water supply linked with food security?

Answer 10

If water supply decreases, droughts can occur and this decreases crop yields.

Question 11

Why is ground water use in agriculture more common than surface water in arid regions?

Answer 11

Because it is arid and there is little surface water

Question 12

in populations living in arid regions, how much of their water supply comes from groundwater? (%)

Answer 12

20%

Question 13

How does vegetation help groundwater recharge?

Answer 13

Water doesn’t dun off and is infiltrated instesad

Question 14

How does vegetation hinder groundwater recharge?

Answer 14

The plants use the water up and so less water is held in the soil

Question 15

Is this very high, high or low porosity?

Answer 15

Low porosity cemented sandstone

Question 16

Is this very high, high or low porosity?

Answer 16

High porosity sandstone

Question 17

Is this very high, high or low porosity?

Answer 17

Very high porosity mudstone

Question 18

Is this high, low or very low permeability?

Answer 18

Low permeability cemented sandstone

Question 19

Is this high, low or very low permeability?

Answer 19

High permeability sandstone

Question 20

Is this high, low or very low permeability?

Answer 20

Very low permeability mudstone

Question 21

Define permeability

Answer 21

The capacity of the material to transmit fluid

Question 22

What is an aquifer?

Answer 22

Rocks that have high enough porosity and permeability to alow water to be withdrawn

Question 23

What is an aquitard?

Answer 23

Rocks that dont have high enough porosity and permeability to alow water to be withdrawn

Question 24

What is an aquiclude?

Answer 24

Impemeable beds of rock that surround permeable, water stransmitting beds

Question 25

How fast does groundwater flow? (m/yr)

Answer 25

4-500m/yr

Question 26

What is an artesian spring?

Answer 26

When permeable rock (aquifer) is ‘sandwiched’ between impermeable rock on both sides (aquicludes). Spaces in the top layer of aquitard (impermeable rock alows arer to escape and is forced upward

Question 27

Where is the world’s largest artesian basin?

Answer 27

Australia

Question 28

How was the Australian artesian basin created?

Answer 28

During times of flood over mainland Australia, layers of marine shale (aquiclude) were deposited over sandstone (aquifer)

Question 29

Up to how old are the waters emerging from the great artesian basin?

Answer 29

2 million years old

Question 30

Why cant water for the great artesian basin be used for irrigation?

Answer 30

The water is too saline

Question 31

What is the differebnce between a spring and oasis?

Answer 31

Nothing really. an oasis is a spring that occurs in a desert

Question 32

Why can over pumping be an issue? (2)

Answer 32

Causes a cone of depression and lowers water table making reaching the water harder and harder

a reversal of flow can cause containation of pumps