Lecture 9 Flashcards Preview

Geography 103 > Lecture 9 > Flashcards

Flashcards in Lecture 9 Deck (36):
1

Define a water table

The line of complete saturation above the groundwater. This is a dynamic and changing boundary

2

Define through flow.

Horizontal flow of water within the soul matrix above the water table. This happens when soil becomes saturated and the water moves due to gravity towards a stream or lake

3

Define groundwater flow.

Underground topographic flow of groundwater due to gravity.

4

Define percolation

Vertical movement of water downward through a soil matrix

5

True or False:
The ground water zone is totally saturated

True

6

True or False:
Ground water supplies lakes and rivers but not oceans.

False. It supplies all three

7

Do larger or smaller sediments promote quicker groundwater flow?

Smaller

8

What is unconfined groundwater?

Groundwater not restricted by an impervious layer of rock

9

Define a perched water table.

A water table present above another water table due to an impervious rock layer

10

What happens to confined groundwater.

It becomes pressurized

11

True or False:
An artesian well occurs when pressurized confined groundwater reaches the surface

True

12

What recharges groundwater?

Precipitation percolating down

13

True or False:
Groundwater has a short residence time

False

14

What can intercept precipitation in its way to groundwater?

Vegetation absorbing water from the ground or catching it in the canopy

15

What is infiltration?

Water entering a soil matrix

16

What is the difference between the zone of aeration and the water table?

The water table is complete saturation and the zone of aeration is only partially saturated

17

Name three methods of water energy movement.

Hydroscopic, capillary, gravitational

18

Define hydroscopic movement of water.

Microscopic particle adhesion. Very small scale

19

Define the capillary movement of water.

Held in the pour matrix

20

Define the gravitational flow of water

Water flowing readily through large spaces

21

What is the order of strength in the methods of water movement

Hydroscopic > capillary > gravitational

22

What three things will increase the permeability of soil?

Add gravel under
Sand on the top
Aerate

23

What is porosity?

% volume pore space in a rock or sediment. It is a measure of holding capacity

24

Does clay have a low or high water retention? Why?

High. Because of the larger surface area. Clay is platelets of minerals and lots of water can adhere to this

25

Define hydraulic conductivity.

Ability of water to flow.

26

Define permeability.

The ability of a substrate to transmit water, requires the water to be connected and varies with pore size.

27

Define and aquitard.

A surface not permeable to water

28

Define and aquifer

A substance containing water

29

What makes a well flow?

There must be surface pressure

30

What three things control groundwater movement

Substrate: porosity and permeability

Pressure: a function of the weight of the water at a depth

Elevation: potential energy above sea level

31

True or False:
Groundwater flows low to high pressure

False

32

Where does water flow when the water table is high?

Down

33

True or false:
Water will flow up towards a low discharge area

True

34

What is hydraulic head?

A function of pressure and elevation that is a length term.

35

What causes a cone of depression?

A well inserted into ground water that drains the surrounding groundwater

36

What is Groundwater?

Water that occupies space in the pores of sediment or rock below the earths surface