Chapter 11: Water Resources

Question 1

Vadose zone/zone of aeration

Answer 1

Unsaturated zone above the water tablle where water percolates down toward the groundwater

Question 2

Phreatic zone/zone of saturation

Answer 2

Area beneath water table, where groundwater is located

Question 3

Long Island aquifers (3)

Answer 3

1. Upper Glacial (unconfined)
2. Magothy (unconfined)
3. Lloyd aquifer (confined)

Question 4

Local (perched) water table

Answer 4

Localized water table that sits above a confining layer and above the actual water table

Question 5

Artesian well

Answer 5

A well in which water is under pressure

Influence of artesian system and municipal water supply

Question 6

Drawdown

Answer 6

Caused by over-pumping of groundwater

Question 7

Cone of depression

Answer 7

Caused by drawdown

Question 8

Saltwater intrusion

Answer 8

Occurs when freshwater near saltwater is overpumped

Question 9

Ghyben-Herzberg equation

Answer 9

Equation for figuring the depth of the freshwater lense

Freshwater lense = x + 40x

x = distance from ground to water table

Question 10

Hydraulic gradient

Answer 10

Slope of groundwater that influences the direction of movement of groundwater flow

Question 11

Hydraulic conductivity

Answer 11

Permeability of material where groundwater is (the ability of water to flow through material)

Question 12

Porosity

Answer 12

Ground material’s ability to store water (i.e. its pore space)

Clay = highest porosity
Sand = 2nd highest

Question 13

Permeability

Answer 13

Ability of water to move through ground material (faster movement of water means higher permeability)

Gravel = highest permeability
Gravel & sand = 2nd highest
Sand = 3rd highest

Question 14

Darcy’s law

Answer 14

Describes the flow of water through a porous medium/flow of groundwater

Q = K(dh/dl)A

Discharge = hydraulic conductivity * slope * area

Units cubed