Como Creek Colorado C-Q data

R code for downloading and analyzing concentration-discharge (C-Q) data from National Ecological Observatory Network (NEON) Como Creek site in Colorado.  The script first downloads the data from the NEON API, removes quality flagged measurements, and averages all data to 15 minute intervals and merges discharge (Q), nitrate (NO3-N) and water quality (specific conductance-SpC and fluorescent dissolved organic matter-fDOM which is then used to estimate dissolved organic carbon-DOC).  This dats is saved as a csv file, which is also included in this repo, so that this step can be bypassed.

The code then analyzes the C-Q relationships of individual snowmelt and rainfall induced pulses by fitting a power function to determine whether concentrations are enriched, diluted or chemostatic.  A normalized hysteresis index is also calculated for each event.  Finally, the code fits a sine model to each day of data to determine the timing and amplitude of the diel signals.