PRINCIPLES OF GROUNDWATER FLOW & GROUNDWATER FLOW TO WELLS Flashcards

1
Q

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

A

mechanical, thermal, chemical

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2
Q

What are the three 3 external forces acting on groundwater?

A

gravity, external pressure, and molecular attraction

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3
Q

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

A

shear stresses

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4
Q

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

A

normal stress

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5
Q

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

A

viscosity

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6
Q

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.

A

Piezometer

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7
Q

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

A

total hydraulic head

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8
Q

Density variation to the head due to _______.

A

Salinity

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9
Q

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

A

Point-water head

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10
Q

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

A

Fresh water head

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11
Q

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

A

Force Potential

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12
Q

True or False. Total mechanical energy= force potential.

A

TRUE

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13
Q

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

A

FALSE. Frictional resistance

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14
Q

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

A

TRUE

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15
Q

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

A

laminar

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16
Q

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

A

Streamlines

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17
Q

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

A

Reynolds number

18
Q

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

A

2000

19
Q

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.

A

TRUE.

20
Q

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.

A

False. Valid only when ….

21
Q

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

A

Flow line

22
Q

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

A

isotropic aquifer

23
Q

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

A

flow net

24
Q

Groundwater cannot pass a __________.

A

no flow boundary

25
Q

___________ boundary represents an equipotential line

A

constant-head boundary

26
Q

For unconfined aquifers, there is also a __________.

A

water table boundary

27
Q

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.

A

TRUE

28
Q

__________ 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.

A

Equipotential lines

29
Q

_______ also function to inject fluids into the ground

A

Wells

30
Q

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

A

TRUE

31
Q

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

A

FALSE. increase

32
Q

____________ 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.

A

Drawdown

33
Q

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

A

cone of depression

34
Q

The head is constant with time

A

steady state flow

35
Q

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

A

Radial flow

36
Q

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

A

Radial flow

37
Q

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

A

Aquifer test

38
Q

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

A

True

39
Q

___________ 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.

A

Slug Test

40
Q

A ____________ is a region in which the aquifer is
replenished

A

recharge boundary

41
Q

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

A

Barrier boundary