Steady‐State Flow Aquifer Tests

Groundwater studies are conducted to evaluate the occurrence, availability, and quality of groundwater. There are numerous practical applications like optimum development of groundwater basins, safe withdrawal, groundwater recharge, seepage from canals and reservoirs, and drainage that require knowledge of the hydraulic characteristics of aquifers. Two basic aquifer properties needed to make a quantitative assessment of such applications are transmissivity and storage coefficient which represent, in a general sense, its abilities to transmit and store water, respectively. The other hydraulic properties of an aquifer are hydraulic resistance, leakage factor, and drainage factor. Performing an aquifer test is an effective way of determining these hydraulic properties of aquifers. Steady-state flow aquifer tests are conducted to determine transmissivity, hydraulic conductivity, and hydraulic resistance; more detailed unsteady-state tests are conducted if other hydraulic properties are also to be evaluated. The objective of this article is to discuss steady-state methods of determining aquifer characteristics. Keywords: groundwater; well hydraulics; pumping test; drawdown; piezometric head; confined aquifer; unconfined aquifer; leaky aquifer; artesian aquifer; aquifer aquifer; artesian aquifer; aquifer constants; transmissivity; storage coefficient; hydraulic conductivity; hydraulic resistance; leakage factor; cylindrical flow; radial flow; spherical flow; steady-state flow; Darcy law; Dupuit–Thiem method; Logan's method; airline method