The non-equilibrium equation can be used to determine the storage coefficient and transmissivity of confined aquifers. These aquifer constants are useful in the design of tubewells and for studying groundwater movement. Several approximate solutions have been developed for the purpose. Some of them are outlined in the following paragraphs: 1. Theis Method: This is a graphical method of superposition that [...]
While porosity is a measure of the water-bearing capacity of the formation, all this water cannot be drained by gravity or by pumping from wells, as a portion of the water is held in the void spaces by molecular and surface tension forces. The volume of water, expressed as a percentage of the total volume of the saturated aquifer, that [...]
Storage coefficient of an aquifer is the volume of water discharged from a unit prism, i.e., a vertical column of aquifer standing on a unit area (1 m2) as water level (piezometric level in confined aquifer—artesian conditions) falls by a unit depth (1 m). For unconfined aquifers (water table conditions) the storage coefficient is the same as specific yield, Fig. [...]