This research quantifies streamflow temporal configuration and demonstrates the advantages of 7 examining the hydrologic record on a day-today basis, heretofore unavailable with statistical-based index 8 parameters. The streamflow chronological structure represents a previously untapped wealth of information 9 that would benefit ecohydrology allowing alternate lines of investigation, re-evaluating past research in a 10 new light, and expanding analysis options for ecohydrologists. Innovative approaches are introduced to 11 quantify this important but overlooked hydrologic property. To accomplish this, a non-index calculus-based 12 differential approach has been developed using the lag(1) temporal autocorrelation signature of streamflow. 13 The techniques for quantifying discharge (Q), day-today discharge change (dQ/dt), rate of day-today dis-14 charge change (d 2 Q/dt 2), and sequential discharge summations, are explained and presented using updated 15 data visualization methods. A dam release river impact case study for the Colorado River at Lees Ferry, 16 Arizona, demonstrates this novel way of analyzing and comparing discharge datasets. A set of highly cus-17 tomizable tools for this new approach can be used as a stand-alone analysis or to complement other existing 18 techniques. The result is a better understanding of the hydrologic regime, permitting more focused research 19 and more effective management planning. 20

Flow duration curves (FDCs) are a mainstay analysis technique examining the composition of streamflow using an exceedance probability approach. But despite the multiple versions developed over the past 100+ years, FDCs have never been able to display day-today discharge information-until now. Presented is a technique to add temporal sequence information to the fundamental FDC by incorporating a lag(1) autocorrelation scatterplot. This modification shows regions of discharge increases (dQ/dt > 0), discharge persistence (dQ/dt = 0), discharge decreases (dQ/dt < 0) and the number and degree of daily discharge changes. The result is a more informative visual representation of streamflow.

Drought and climate change are important factors to include in any hydrologic analysis. Current weather-related events in California, such as the extended drought and recent multiple atmospheric rivers, demonstrate how quickly hydrologic conditions can change. A lag(1) autocorrelation analysis of California Climate Division 2 (Sacramento Drainage) using monthly Palmer Hydrologic Drought Index (PHDI) values was conducted to find data ranges, persistence of conditions, along with seasonal and historical drought patterns. Results show distinct conditions within the hydrologic-climatic system which include periods of (a) persistent drought, (b) persistent wet, (c) transition from drought to wet, and (d) transition from wet to drought. Month-to month PHDI changes are quantified using a summation infographic based on the autocorrelation scatterplot.