Final answer:
Aquifer depletion occurs when underground aquifers are being pumped out faster than they can be replenished. It has various causes and effects, including decreased water table, saltwater intrusion, and land subsidence.
Step-by-step explanation:
Aquifer depletion occurs when the water in underground aquifers is being pumped out faster than it can be replenished. This can have various causes and effects. Some causes of aquifer depletion include excessive pumping for agricultural irrigation, industrial use, and domestic consumption. When aquifers are depleted, it can lead to a decrease in the water table, which can have several effects such as increased costs of well drilling, saltwater intrusion, and land subsidence.