What is the definition of porosity?

Porosity is defined as the measure of void spaces in a material. This concept is essential in fields such as geology and hydrology, as it relates to how much fluid a material, such as soil or rock, can hold. High porosity implies that a material has many pores or voids, allowing it to store more water, while low porosity indicates that there are fewer spaces for water to occupy. Understanding porosity is crucial for water well monitoring, as it affects groundwater flow and availability. The other options address different aspects related to soil and water, but they do not accurately define porosity.