User-focused evaluation of National Ecological Observatory Network streamflow estimates

Abstract

Accurately estimating stream discharge is crucial for many ecological, biogeochemical, and hydrologic analyses. As of September 2022, The National Ecological Observatory Network (NEON) provided up to 5 years of continuous discharge estimates at 28 streams across the United States. NEON created rating curves at each site in a Bayesian framework, parameterized using hydraulic controls and manual measurements of discharge. Here we evaluate the reliability of these discharge estimates with three approaches. We (1) compared predicted to observed discharge, (2) compared predicted to observed stage, and (3) calculated the proportion of discharge estimates extrapolated beyond field measurements. We considered 1,523 site-months of continuous streamflow predictions published by NEON. Of these, 39% met our highest quality criteria, 11% fell into an intermediate classification, and 50% of site-months were classified as unreliable. We provided diagnostic metrics and categorical evaluations of continuous discharge and stage estimates by month for each site, enabling users to rapidly query for suitable NEON data.

Relationship between isotope ratios in precipitation and stream water across watersheds of the National Ecological Observation Network

“…The δP and δQ data show seasonality and suggest a possibly time et al, 2023). Additionally, StorAge Selection (SAS) functions were not possible with the limitations of discharge data (Benettin et al, 2017;Rhea et al, 2023). This time invariant MTT presented here needs to be considered with our results but should be noted that McGuire nutrients, freshwater, and the atmosphere (Goodman et al, 2015;NEON, 2023b).…”

“…The δP and δQ data show seasonality and suggest a possibly time varying residence time distribution. A flow‐corrected time based on daily discharge similar to McGuire et al (2005) did not improve MTT calculations, in part due to the limitations of discharge data (Rhea et al, 2023). Additionally, StorAge Selection (SAS) functions were not possible with the limitations of discharge data (Benettin et al, 2017; Rhea et al, 2023).…”

“…A flow‐corrected time based on daily discharge similar to McGuire et al (2005) did not improve MTT calculations, in part due to the limitations of discharge data (Rhea et al, 2023). Additionally, StorAge Selection (SAS) functions were not possible with the limitations of discharge data (Benettin et al, 2017; Rhea et al, 2023). This time invariant MTT presented here needs to be considered with our results but should be noted that McGuire et al (2005) and Kirchner et al (2001) included discharge changes in MTT and obtained similar fits to the stream isotope data.…”

“…We did not weigh δQ based on stream water because of limitations with NEON discharge data (Rhea et al, 2023). von Freyberg et al (2018) showed that flow weighting the δQ yielded F yw that was roughly 26% larger than their unweighted counterparts F yw , but Segura (2021) found indistinguishable results considering weighted or unweighted output signals in the F yw estimates.…”

MacroSheds: A synthesis of long‐term biogeochemical, hydroclimatic, and geospatial data from small watershed ecosystem studies

“…NEON provides data products that will be integral to a future version of the MacroSheds dataset. Currently, NEON remains in its early operational phase, and its data products will be included in MacroSheds pending resolution of water quality and continuous discharge data anomalies that require further attention (Rhea et al 2023 b ).…”