what is the difference between water table and aquifer?
The water that is found under the surface of the Earth and is responsible for the presence of water in the wells, tube wells, and springs is called ground water. The porous regions in the soil and gaps in between the rocks are filled with this ground water. The upper limit of this layer of ground water, which fills into all the porous spaces between the soils, is called the water table.
Rain water and water from the other water bodies on the surface of the Earth seeps down into the soil and is stored as ground water. This passing down of water through the soil is known as infiltration.
This infiltrated water accumulates in the deep underground, where a layer of impermeable rocks blocks the water from seeping down further. Such places that have an impermeable layer of rocks leading to the accumulation of water over it are known as aquifers.
Aquifer: An underground layer of permeable rock, sediment (usually sand or gravel), or soil that yields water. The pore spaces in aquifers are filled with water and are interconnected, so that water flows through them. Sandstones, unconsolidated gravels, and porous limestones make the best aquifers. They can range from a few square kilometers to thousands of square kilometers in size.
Water Table:The upper surface of an area filled with groundwater, separating the zone of aeration (the subsurface region of soil and rocks in which the pores are filled with air and usually some water) from the zone of saturation (the subsurface region in which the pores are filled only with water). Water tables rise and fall with seasonal moisture, water absorption by vegetation, and the withdrawal of groundwater from wells, among other factors. The water table is not flat but has peaks and valleys that generally conform to the overlying land surface.