Heath.1

Question 1

Hydrosphere

Answer 1

The term used to refer to the waters of the Earth and, in its broadest usage, includes all water, water vapor, and ice regardless of whether they occur beneath, on, or above the Earth’s surface.

Question 2

Unconsolidated Deposits

Answer 2

Material derived from the disintegration of consolidated rocks.

Question 3

Types of unconsolidated deposits (in order of increasing grain size):

Answer 3

Clay, Silt, Sand, Gravel

Question 4

Consolidated Rocks

Answer 4

Rocks that consist of mineral particles of different sizes and shapes that have been welded by heat and pressure or by chemical reactions into a solid mass.

Question 5

Bedrock

Answer 5

A really squishy term that in hydrologic circles refers to the layer of consolidated rock that underlies the surface layer/s of unconsolidated deposits.

Question 6

Primary Openings

Answer 6

Voids existing within any rock structure that formed at the same time that the rock itself. Think pore structure in sand, gravel, etc. Even a lava-tube would be considered a primary opening.

Question 7

Secondary Openings

Answer 7

Voids in a rock structure that form after the rock itself was formed. Think cracks in granite or the cavern systems within limestone.

Question 8

Semi-consolidated Rocks

Answer 8

Rocks in which openings include both pores and fractures (both primary and secondary openings).

Question 9

Unsaturated Zone

Answer 9

The region immediately below the earth’s surface (in any given area) that contains both water and air in its primary and secondary openings.

Question 10

Regions of the Unsaturated Zone (top-down)

Answer 10

Soil zone, intermediate zone, capillary fringe (upper part).

Question 11

Saturated Zone

Answer 11

Sub-surface region, below the unsaturated zone in which all of the interconnected primary and secondary openings have filled with water (no-air).

aka-Ground water

Question 12

Water Table (simple definition)

Answer 12

Basically the dividing line between the saturated and unsaturated zones.

Question 13

Water Table (technical definition)

Answer 13

The level in the saturated zone at which the hydraulic pressure is equal to atmospheric pressure. Represented by the water level in an unused well (no cone of depression).

Question 14

Hydrologic Cycle

Answer 14

The constant (cyclical-ish) movement of water above, on, and below the Earth’s surface.

Question 15

Parts of the Hydrologic Cycle

Answer 15

Evaporation, Transportation (via clouds), Precipitation, Infiltration/Runoff, Groundwater Movement/Overland Flow.

Biology complicates things here…

Question 16

Infiltration

Answer 16

The absorption/movement of precipitated water down below the earth’s surface under the force of gravity (and capillary action).

Question 17

Overland Flow

Answer 17

Surface movement of the precipitated water that falls in excess of the ground’s infiltration rate.

Question 18

Aquifer

Answer 18

A rock unit that will yield water in a usable quantity to a well or a spring.

Question 19

Confining Bed

Answer 19

A rock unit that having very low hydraulic conductivity that restricts the movement of ground water either into or out of adjacent aquifers.

Question 20

Unconfined Aquifer

Answer 20

An aquifer in which the upper surface of the saturated zone is free to rise or fall without restriction. Most often located between the Earth’s surface and the first confining bed.

Question 21

Confined Aquifer

Answer 21

An aquifer that is bounded by confining beds from both above and below.

aka-Artesian Aquifer

Question 22

Water-Table Well

Answer 22

A well drilled down into an unconfined aquifer.

Question 23

Artesian Well

Answer 23

A well drilled down into an unconfined aquifer.

Question 24

Potentiometric Surface

Answer 24

The level of the water in a tightly-cased artesian well. Generally rises above the level of the top of the aquifer due to the pressure exerted on the water within the aquifer by the weight of the overlying rock.

Question 25

Flowing Artesian Well

Answer 25

A well drilled down into an artesian well which has a potentiometric surface that is higher than the level of the ground at the top of the well. Thus the water coming out from the well flows out onto the surface of the Earth.

Question 26

Porosity

Answer 26

The ratio of openings (voids) to the total volume of a sample of soil or rock.

Question 27

Porosity Equation

Answer 27

n=(Vt-Vs)/Vt

n=Vv/Vt

n is porosity
Vt is the total volume of sample
Vs is the volume of the solids in a sample
Vv is the volume of the voids in a sample

Question 28

Specific Yield

Answer 28

That portion of the water contained in a sample that will drain out under the force of gravity.

Question 29

Specific Retention

Answer 29

The volume of water that remains within the voids of a sample (due to surface film cohesion and capillary action) after gravity drains the specific yield.

Question 30

Relationship between porosity, specific yield, and specific retention

Answer 30

n=Sy+Sr

n is porosity
Sy is specific yield
Sr is specific retention

Question 31

Equation for Specific Yield

Answer 31

Sy= Vd/Vt

Sy is specific yield
Vd is the volume of water that drains under the force of gravity
Vt is the total volume of the sample

Question 32

Equation for Specific Retention

Answer 32

Sr=Vr/Vt

Sr is the specific retention
Vr is the volume of water retained in a sample after water is drained under force of gravity
Vt is the total volume of the sample

Question 33

Vertical Datum of 1929

Answer 33

aka-Sea Level

Question 34

Total Head

Answer 34

The depth to water in a non-flowing well subtracted from a specific measurement point (or datum plane, such as sea-level).

Question 35

Components of a Total Head

Answer 35

Ht=z+Hp+Hv

Ht is the total head
z is the elevation head
Hp is the pressure head
Hv is the velocity head (functionally zero when dealing with ground-water, and thus typically ignored

Question 36

Elevation Head

Answer 36

Distance from the bottom of a drilled well to a given datum plane (usually sea-level)

Question 37

Pressure Head

Answer 37

Distance from the bottom of a well to the surface of the water in that well (aka-water table/potentiometric surface)

Question 38

Head Loss

Answer 38

The decrease in the total head between two different wells drilled into the same aquifer.

Question 39

Hydraulic Gradient

Answer 39

The change in the total head per unit distance in a given direction between wells in a given aquifer (hL/L).

Frequently given in inconsistent units such as m/km.

Question 40

Hydraulic Conductivity

Answer 40

The quantity of ground water that moves through a given unit of aquifer per unit time. Expressed through “Darcy’s Law.”

Depends on the size and arrangement of the water-transmitting openings, and on the fluid dynamics of the water (kinematic viscosity, density, and the strength of the gravitational field).

Question 41

Darcy’s Law

Answer 41

Q=KA (dh/dl)

Q is the quantity of water per unit time
K is the hydraulic conductivity of the sample
(dh/dl) is the hydraulic gradient

Question 42

Darcy’s Law (rearranged as a definition of Hydraulic Conductivity)

Answer 42

K= (Qdl/Adh)= (m^3 d^-1)(m)/(m^2m) = m/d

Thus units of hydraulic conductivity are those of velocity: distance divided by time.

Question 43

Isotropic Hydraulic Conductivity (K)

Answer 43

The situation in which the hydraulic conductivity is essentially the same in all directions within a given region of an aquifer.

Question 44

Anisotropic Hydraulic Conductivity

Answer 44

That situation in which the hydraulic conductivity of an aquifer is different in different directions.

Question 45

Ground-water Hydrology

Answer 45

A subdivision of the science of hydrology that deals with the occurrence, movement, and quality of water beneath the Earth’s surface.