Midterm 1 Terminology

Question 1

Porosity

Answer 1

The pore space of an aquifer is the spaces or voids between the solid material. The porosity of the aquifer is the volume of void space to the total volume, typically expressed as a percentage.

Question 2

Moisture Content

Answer 2

the quantity of water contained in a material

Question 3

Saturation

Answer 3

Saturated conditions occur when all of the voids, spaces, and cracks are filled with water. Unsaturated conditions occur when the voids, spaces, and cracks between soil, sand, gravel, or rock are filled with a combination of air and water.

Question 4

Vadose Zone

Answer 4

Area where water content varies depending on weather

Question 5

Capillary Fringe

Answer 5

The area where groundwater is drawn up into the pores or spaces in the sediment above the water table by capillary action

Question 6

Saturated Zone

Answer 6

Area below the water table, contains groundwater

Question 7

Water Table (Phreatic Surface)

Answer 7

Location where groundwater is at atmospheric pressure

Question 8

Unconfined Aquifer (Water Table Aquifer, Phreatic Aquifer)

Answer 8

An aquifer that’s upper bound is the water table

Question 9

Perched Aquifer

Answer 9

An aquifer that is above the zone of saturation, in the vadose zone

Question 10

Confined Aquifer

Answer 10

An aquifer that’s upper bound has a confining layer that does not transmit water, and is under pressure

Question 11

Artesian Aquifer

Answer 11

An aquifer that is confined between impermeable material that is under positive pressure. When a well is drilled into an artesian aquifer, water flows to the surface

Question 12

Aquitard

Answer 12

Confining layer of an aquifer that leaks

Question 13

Aquifuge

Answer 13

Confining layer of an aquifer that is impermeable but contains water (ex: clay)

Question 14

Aquiclude

Answer 14

Confining layer of an aquifer that is impermeable and does not contain water

Question 15

Lithography

Answer 15

Types of rock

Question 16

Stratigraphy

Answer 16

Subsurface layers

Question 17

Igneous Rock

Answer 17

Ex: granite. Hard, can see mineral grains

Question 18

Sedimentary Rock

Answer 18

Clastic Sedimentary (ex: sandstone) - formed by consolidation, possible porosity

Nonclastic sedimentary (Ex: limestone) - formed by precipitation

Question 19

Metamorphic Rock

Answer 19

Rocks formed from igneous and sedimentary rocks

Question 20

Primary Porosity vs Secondary Porosity

Answer 20

Primary: porosity that is present when the geologic layer was originally formed

Secondary: porosity formed by dissolution, fracturing

Question 21

Drift

Answer 21

Transport of material while materials are weathered by glaciers

Question 22

Till

Answer 22

Material transported by ice, unsorted

Question 23

Moraine

Answer 23

Material transported by ice, organized structures

Question 24

Drumlin

Answer 24

Oval or elongated hills believed to have been formed by ice

Question 25

Esker

Answer 25

Scraggly ridges made of sand and gravel deposited by glacial meltwater

Question 26

Outwash

Answer 26

Material transported by water, sorted by particle size (settle out by Stoke's Law)

Question 27

Alluvial, fluvial deposits

Answer 27

Geologic material found in ancient river bottoms, tends to be coarser grained

Question 28

Lacustrine Desposits

Answer 28

Geologic material found in ancient lake bottoms, tends to be finer grained

Question 29

Soil Texture

Answer 29

12 soil texture classes, based on a soil texture triangle, which uses % of sand, silt, and clay to type the soil texture. Soil ranges also by particle size

Question 30

Soil Color

Answer 30

``` Munsell Color System Hue • R - red • YR - yellow red • Y - yellow Value • darkness or lightness Chroma • how clearly does the hue show ```

Question 31

Aquifer

Answer 31

A geological layer that contains and can transmit water

Question 32

Evapotranspiration vs Potential Evapotranspiration

Answer 32

Evapotranspiration is hard to estimate, as it depends on soil moisture, type of plants, sunlight, etc. If we assumed soil moisture is not a limiting factor (under conditions of unlimited water), ET = PET. PET can also be estimated empirically, using the Blaney-Criddle of Thornthwaite Eqn's

Question 33

Homogeneous Assumption

Answer 33

Hydraulic Conductivity does not change with position

Question 34

Heterogeneous Assumption

Answer 34

Hydraulic Conductivity changes with position Different types of heterogeneity • Layered • Trending • Discontinuous

Question 35

Isotropy

Answer 35

Hydraulic Conductivity is the same in the x and z direction

Question 36

Anisotropy

Answer 36

Hydraulic Conductivity is not the same in x and z directions

Question 37

Transmissivity

Answer 37

the ability of the aquifer to transmit groundwater throughout its entire saturated thickness

Question 38

Specific Storage

Answer 38

= volume of water that a unit volume of aquifer releases under a unit decline in piezometric head

Question 39

Storativity

Answer 39

specific storage in units of flow per unit width

Question 40

Specific Yield

Answer 40

water yielded from the dewatering of pores

Question 41

Flow Nets

Answer 41

Graphical depiction of equipotential lines (h = constant) and flow lines). Used in interpretation of numerical solutions, h = f(x,y,z,t)