What is an aquifer?

An aquifer is defined as an underground water reservoir that stores and transmits water, enabling access for extraction through wells or natural springs. Aquifers consist of permeable geological formations such as sand, gravel, or fractured rock that can hold significant amounts of water. This stored water is usually replenished by precipitation that infiltrates the ground and moves downward through the soil and rock layers.

Aquifers are critical for supplying water for agricultural, residential, and industrial uses, especially in areas where surface water is scarce. Understanding the characteristics and behavior of aquifers is essential for effective water resource management, including maintaining sustainable water supplies and protecting groundwater quality.

The other options do not accurately describe what an aquifer is. A surface water body refers to water that is found on the Earth's surface, like lakes or rivers, while a type of well specifically refers to a structure used to access groundwater rather than the underground reservoir itself. A method to measure groundwater could involve various techniques, but it doesn't define what an aquifer is.