GLG 301 Lecture Notes - Lecture 13: Soviet Central Asia, Artesian Aquifer, Salton Sea
Document Summary
Natural discharge: water flows out of aquifers where they intersect the free surface springs. Artesian systems: artesian water is water that is naturally under pressure so it rises above the surface of the aquifer it is in to its potentiometric (or artesian-pressure) surface. If this surface is above the ground level, you have a flowing artesian well (artesian spring or well). The potentiometric surface generally loses elevation away from the recharge area (due to leakage and resistance to flow). Found in the great plains, atlantic and gulf coasts, etc. , where there are confined aquifers that have recharge at higher elevations: same principle as water towers. Urbanization can cause a regional depression of the water table: salt-water influx. Extraction of lower density fresh water near coasts can result in influx of higher density salt water into wells. In florida diversion plus water extraction have combined to result in salt-water encroachment both at and below the surface.
