  It has been previously observed that during a pumping test in heterogeneous
media, drawdown data from different time periods collected at a single location
produce different estimates of aquifer properties and that Theis type-curve
inferences are more variable than late-time Cooper-Jacob inferences. In order
to obtain estimates of aquifer properties from highly transient drawdown data
using the Theis solution, it is necessary to account for this behavior. We
present an approach that utilizes an exponential functional form to represent
Theis parameter behavior resulting from the spatial propagation of a cone of
depression. This approach allows the use of transient data consisting of
early-time drawdown data to obtain late-time convergent Theis parameters
consistent with Cooper-Jacob method inferences. We demonstrate the approach on
a multi-year dataset consisting of multi-well transient water-level
observations due to transient multi-well water-supply pumping. Based on
previous research, transmissivities associated with each of the pumping wells
are required to converge to a single value, while storativities are allowed to
converge to distinct values.
