What does storativity measure in an aquifer?

Storativity is a crucial parameter in hydrogeology that indicates the amount of water an aquifer can store and release. Specifically, it measures the volume of water that an aquifer releases per unit surface area of the aquifer due to changes in hydraulic head. This is an important characteristic because it informs us about the aquifer’s capacity to supply water under pumping conditions or during periods of recharge.

In essence, storativity encompasses both the storage properties of the aquifer material (such as porosity) and the compressibility of the water and the aquifer rock matrix. A higher storativity value signifies a greater ability of the aquifer to hold and yield water as the water level fluctuates. This characteristic is essential for aquifer management and resource planning, particularly for sustainable water use.

The other options focus on different properties unrelated to storativity. For instance, the density of water is a separate physical property and does not reflect the storage capacity of an aquifer. The speed at which water flows through the aquifer pertains to hydraulic conductivity, while temperature relates to groundwater thermal properties, neither of which are measured by storativity.