Hydromorphologic Recession Analysis: Accounting for Human Influences in Watershed Behaviors

Integrated management of ground and surface waters has generally relied on baseflow characterization to understand the temporal variability in the contribution of watershed storage to streamflow. Recent research, however, indicates that small disturbances attributed to humans can impact our ability to characterize baseflow behaviors. In this study, we present an approach to account for human impacts on the estimation of baseflow recession parameters in California's Central Valley. The framework assesses how baseflow characterization is impacted by the combination of groundwater abstractions and surface water management strategies used to meet both residential and agricultural water demands. The results highlight the importance of accounting for human influences to characterize watershed properties by evaluating traditional (i.e. natural) and human-corrected recession parameters. Such results can influence studies ranging from water resources management to stream restoration projects that rely on accurate accounting of baseflow, especially during low flows.