ASBOG Hydrogeology 2

Question 1

Which dimensionless number is used to compare advective transport to diffusive transport of solutes in groundwater?

Accepted Answer

Peclet number

Answer

The Peclet number (Pe) is the ratio of advective to diffusive solute transport; high Pe means advection dominates.

Question 2

A confined aquifer has a storage coefficient of 5×10⁻⁴. This value indicates that water release is primarily due to:

Accepted Answer

Compression of the aquifer and expansion of water

Answer

In confined aquifers, the storativity reflects elastic compression of the aquifer skeleton and expansion of pore water under pressure change.

Question 3

Which of the following best describes a perched aquifer?

Accepted Answer

A saturated zone above the regional water table, separated by an unsaturated zone

Answer

A perched aquifer is a locally saturated zone sitting atop a low-permeability lens above the main water table.

Question 4

In the context of aquifer testing, what does the term 'skin effect' refer to?

Accepted Answer

Near-wellbore damage or improvement affecting wellbore efficiency

Answer

Skin effect describes additional head loss (positive skin = damage, negative skin = improvement) caused by near-wellbore conditions.

Question 5

The Ghyben-Herzberg relation describes the depth of the freshwater-saltwater interface below sea level as approximately how many times the freshwater head above sea level?

Accepted Answer

40

Answer

The Ghyben-Herzberg relation gives the interface depth as 40 times the freshwater head above sea level, derived from the density ratio of freshwater to saltwater.

ASBOG - Association of State Boards of Geology Practice Test

ASBOG - Association of State Boards of Geology Practice Test

ASBOG Hydrogeology 2