Calculating accurate discharge timeseries data and understanding how flow rates change over varying time scales is a critical component of assessing biological and climatic functionality within aquatic ecosystems. NEON produces a record of continuous discharge data at 27 stream and river monitoring sites across the United States. As of January 2025, the NEON Continuous discharge data product (DP4.00130.001) publishes cleaned and gap-filled data (period beginning 2021-10-01 for most sites) to produce a timeseries that is, to the greatest extent possible, free of both gaps and erratic periods.
During the data cleaning process, the timeseries is carefully reviewed and quality flags are applied to data gaps and periods that require correction. Any shifts in the data are adjusted by adding or subtracting a constant offset. Flagged periods are then corrected using gap-filling methods. For shorter data gaps (minutes to hours), a linear interpolation or constant value method can be applied between the known data points. For longer data gaps (days to weeks), coefficients derived from regression models can be applied to fill missing time periods based on the relationship between a co-located pressure transducer sensor, water quality sensor, or discharge data from another nearby monitoring station (e.g., a USGS gauging station).
Indicator flags accompany the discharge data to denote whether a correction method was applied, and, if so, when in the processing pipeline the correction was applied, and which correction method was used. The uncorrected discharge record is also provided in the download package, ensuring that all data are reproducible, and all corrections are transparent to the end user. In providing cleaned and gap-filled records of discharge at aquatic sites across the United States, NEON data supports critical research to better understand the degree to which freshwater ecosystems are changing at the continental scale.