Pumping tests are performed during aquifer characterization to gain conceptual understanding about the system through diagnostic plots and to estimate hydraulic properties. Recovery tests consist of measuring head response in observation and/or pumping wells after pumping termination. They are especially useful when the pumping rate cannot be accurately controlled. They have been traditionally interpreted using Theis' recovery method, which yields robust estimates of effective transmissivity, but does not provide information about the conceptual model. Agarwal proposed a method, which has become standard in the oil industry, to obtain both early and late time reservoir responses to pumping from recovery data. However, the validity of the method has only been tested to a limited extent. In this work, we analyze Agarwal's method in terms of both drawdowns and log‐derivatives for non‐ideal conditions: leaky aquifer, presence of boundaries and one dimensional flow. Our results show that Agarwal's method provides excellent recovery plots (i.e., the drawdown curve that would be obtained during pumping) and parameter estimates for nearly all aquifer conditions, provided that a constant pumping rate is used and the log‐derivative at the end of pumping is constant, which is too limiting for groundwater hydrology practice, where observation wells are usually monitored. We generalize Agarwal's method by (1) deriving an improved equivalent time for time‐dependent pumping rate, and (2) proposing to recover drawdown curves by extrapolating the pumping phase drawdowns. These yield excellent diagnostic plots, thus facilitating the conceptual model analysis, for a broad range of conditions.
Planform geometry, spatial heterogeneity, and large wood abundance and distribution were characterized using combined remote imagery and field surveys along lengths of 20‐28 km in four river corridors (channels and floodplains) in northwestern Montana. Study sites included four planform geometries: meandering, straight, braided, and multichannel. Planform spatial heterogeneity of channels and floodplains, such as proportion of the active channel in bars, sinuosity, braiding index, and the number of active channels, differs in relation to channel planform type. Braided and multichannel rivers have significantly greater spatial heterogeneity of channels and floodplains and store significantly greater volumes of wood in the channel. Wood is preferentially stored in jams and jams are preferentially stored in shallow areas of the active channel (midchannel bars, inner bends, secondary channels) and in abandoned channels on the floodplain. We interpret these results using a conceptual model in which boundary conditions create sufficient valley‐bottom width for the development of planform spatial heterogeneity, which then promotes storage of large wood. The results of this study can inform management that protects or restores spatial heterogeneity.