Quantifying streamflow properties using a calculus‐based differential approach

Abstract

This research quantifies streamflow temporal configuration and demonstrates the advantages of examining the hydrologic record on a day‐to‐day basis, heretofore unavailable with statistical‐based index parameters. The streamflow chronological structure represents a previously untapped wealth of information that would benefit ecohydrology allowing alternate lines of investigation, re‐evaluating past research in a new light and expanding analysis options for ecohydrologists. Innovative approaches are introduced to quantify this important but overlooked hydrologic property. To accomplish this, a non‐index calculus‐based differential approach has been developed using the lag(1) temporal autocorrelation signature of streamflow. The techniques for quantifying discharge (Q), day‐to‐day discharge change (dQ/dt), rate of day‐to‐day discharge change (d2Q/dt2) and sequential discharge summations are explained and presented using updated data visualization methods. A dam release river impact case study for the Colorado River at Lees Ferry, Arizona, demonstrates this novel way of analyzing and comparing discharge datasets. A set of highly customizable tools for this new approach can be used as a stand‐alone analysis or to complement other existing techniques. The result is a better understanding of the hydrologic regime, permitting more focused research and more effective management planning.

Integrating ecohydrology and ecohydraulics

“…Although hydrologic and hydraulic interactions are extensively described by many papers, introduction of a relatively new, the high-resolution (day-to-day) streamflow records based on non-index mathematical calculus, such as the autocorrelation signature approach in special issue is significant. This approach has successfully quantified and discussed the discharge variability in Colorado River dam in Arizona (USA) (Koehler, 2023). As the study on high-resolution discharge data is useful for ecohydrological modelling and successful river management, a rainfall-runoff (R-R) modelling approach of the daily observed discharge being used to determine the hydropower potential of the Pandoh Dam of the ungauged Beas River (Indian Himalaya) has also contributed significantly to the river management in the region (Kumar et al, 2024).…”