In an unconfined aquifer, which is an aquifer where the upper water surface, called the water table, is free to rise and fall and is in direct contact with the atmosphere through overlying unsaturated material, water is stored within the pore spaces of the aquifer material. When the water table drops, water is released from storage due to the force of gravity. The fundamental difference between specific yield and specific retention lies in what portion of this stored water they represent regarding its drainability by gravity.
Specific Yield (Sy) represents the volume of water that *drainsby gravity from a saturated unit volume of an unconfined aquifer material. This is the water that is actually released from storage and becomes available for pumping or natural discharge as the water table declines. I....
Log in to view the answer
