PRINCIPLES OF GROUNDWATER FLOW & GROUNDWATER FLOW TO WELLS

Question 1

Groundwater possesses energy in __________, ____________, and __________ forms.

Answer 1

mechanical, thermal, chemical

Question 2

What are the three 3 external forces acting on groundwater?

Answer 2

gravity, external pressure, and molecular attraction

Question 3

A force resisting the fluid movement and acts tangentially to the surface of the solid.

Answer 3

shear stresses

Question 4

A force resisting the fluid movement and acts perpendicularly to the surface.

Answer 4

normal stress

Question 5

The internal molecular attraction of the fluid itself resists the movement of fluid molecules past each other This shearing resistance is known as the ___________.

Answer 5

viscosity

Question 6

A device used to measure liquid pressure in a system by measuring the height to which a column of the liquid rises against gravity, or a device that measures the pressure
of groundwater.

Answer 6

Piezometer

Question 7

The ___________ is equal to the sum of the elevation head and the pressure head.

Answer 7

total hydraulic head

Question 8

Density variation to the head due to _______.

Answer 8

Salinity

Question 9

The water level in the well filled with water coming from a point in an aquifer and which is just enough to balance the pressure in the aquifer at that point

Answer 9

Point-water head

Question 10

The height of a column of fresh water in a well that is just sufficient to balance the pressure in the aquifer at that point

Answer 10

Fresh water head

Question 11

Total mechanical energy per unit mass to be equal to the sum of the kinetic energy, elevation energy, and pressure

Answer 11

Force Potential

Question 12

True or False. Total mechanical energy= force potential.

Answer 12

TRUE

Question 13

True or False. As groundwater moves, it encounters no resistance between the fluid and the porous media.

Answer 13

FALSE. Frictional resistance

Question 14

True or False. Groundwater is warmed slightly as it flows and mechanical energy is converted to thermal energy

Answer 14

TRUE

Question 15

Slowly moving fluids are dominated by viscous forces. There is a low energy level and the resulting fluid flow ____________

Answer 15

laminar

Question 16

In laminar flow, molecules of water follow smooth lines, called __________.

Answer 16

Streamlines

Question 17

Relates the four factors that determine whether the flow will be laminar or turbulent.

Answer 17

Reynolds number

Question 18

If R exceeds a value of __________ then it is turbulent flow

Answer 18

2000

Question 19

True or False. Turbulence in ground water is difficult to detect The inception of fluid turbulent flow in groundwater has been reported at a Reynolds Number ranging from 60.

Answer 19

TRUE.

Question 20

True or False. Experimentation has shown that Darcy’s Law is not valid when are such that the resistive forces of viscosity predominate. These conditions prevail when the Reynolds number is less than 1 to 10.

Answer 20

False. Valid only when ….

Question 21

An imaginary line that traces the path that a particle of groundwater would follow as it flows to the aquifer

Answer 21

Flow line

Question 22

In an ___________, flow lines will cross equipotential lines at right angles

Answer 22

isotropic aquifer

Question 23

Steady flow conditions may be solved by graphical construction of a ________ which is a network of equipotential lines and associated flow lines.

Answer 23

flow net

Question 24

Groundwater cannot pass a __________.

Answer 24

no flow boundary

Question 25

___________ boundary represents an equipotential line

Answer 25

constant-head boundary

Question 26

For unconfined aquifers, there is also a __________.

Answer 26

water table boundary

Question 27

True or False. If there is recharge or discharge across the water table, flow lines will be at an oblique angle to the water table If there is no recharge across the water table, flow lines can be parallel to it.

Answer 27

TRUE

Question 28

__________ are like contour lines on a map that trace lines of equal altitude. In this case the "altitude" is electric potential or voltage. They are always perpendicular to the electric field.

Answer 28

Equipotential lines

Question 29

_______ also function to inject fluids into the ground

Answer 29

Wells

Question 30

True or False. As means of groundwater management, wells are sometimes used artificially to recharge aquifers at rates greater than natural recharge

Answer 30

TRUE

Question 31

True or False. During injection, there is a decrease in the head of the aquifer.

Answer 31

FALSE. increase

Question 32

____________ is the change in hydraulic head observed at a well in an aquifer, typically due to pumping a well as part of an aquifer test or well test.

Answer 32

Drawdown

Question 33

Will form in the aquifer around a pumping well as the water level declines.

Answer 33

cone of depression

Question 34

The head is constant with time

Answer 34

steady state flow

Question 35

Often observed following other flow regimes. The emergence of _________ in an infinite conductivity hydraulically fractured well.

Answer 35

Radial flow

Question 36

This type of flow exists in the time period before the pressure transient has reached the boundaries of the reservoir (infinite acting time period).

Answer 36

Radial flow

Question 37

____________ is conducted to evaluate an aquifer by " the aquifer through constant pumping, and observing the aquifer's " response"(drawdown) in observation wells.

Answer 37

Aquifer test

Question 38

True or False. Aquifer testing is a common tool that hydrogeologists use to characterize a system of aquifers, aquitards and flow system boundaries.

Answer 38

True

Question 39

___________ is a particular type of aquifer test where water is quickly added or removed from a groundwater well, and the change in hydraulic head is monitored through time, to determine the near well aquifer characteristics.

Answer 39

Slug Test

Question 40

A ____________ is a region in which the aquifer is replenished

Answer 40

recharge boundary

Question 41

A __________ is an edge of the aquifer, where it terminates, either by thinning or abutting a low permeability formation, or has been eroded away.

Answer 41

Barrier boundary