What does a slug test measure?

A slug test is a method used to measure the hydraulic conductivity or permeability of an aquifer. During this test, a sudden change in water level in a well is created by quickly removing a 'slug' of water, and the rate at which the water level returns to equilibrium is observed. The speed of the recovery provides information about how easily water can flow through the porous medium surrounding the well, which directly relates to localized values of permeability.

This method is vital in hydrogeology as it helps in assessing the aquifer properties needed for groundwater modeling and management. Understanding permeability is key for various applications, including water resource development, environmental assessments, and contamination studies. In contrast, the other options pertain to different aspects of hydrogeological studies that are not addressed by a slug test.