Determination of unsteady radius of influence during pumping from pressurized aquifers

Abstract

In case of pumping from a pressurized aquifer at a dynamic water level located above its roof, during the period of unsteady water inflow to the borehole, the pumped water is obtained at the expense of “elastic reserve” (an aquifer not communicating with other aquifers or surface water bodies within the area of the depression funnel). “Elastic reserve”, according to V.N. Shchelkachev, is the volume of water displaced into the well during elastic expansion of water and water-bearing rocks due to pressure drop in the depression area.