This data release contains detailed information on 267 individual flow events 
observed on the Kansas River, USA from October 2013 - August 2022. Flow events
were delineated from the discharge record of a USGS gage located in De Soto,
KS (gage #06892350), 48.9 km upstream of the river outlet [delineation info?].

The main file of the release is 'ks_river_event_summary.csv', which contains
723 variables describing various characteristics of each observed flow event.
A description of each of these variables is provided at the end of this readme.

The shapefiles that accompany the .csv provide the locations where the event
characteristics were measured. 'ksrb_boundary.shp' delineates the entire Kansas
River Basin (KSRB), 'huc8_boundaries.shp' delineates the 43 HUC 8-level 
subbasins that together make up the KSRB, 'ksrb_outlet.shp' marks the location 
of the USGS gage from which events were delineated, and 'reservoirs.shp' 
delineates the seven major reservoirs in the KSRB that regulate flow at the 
outlet.

Variables in 'ks_river_event_summary.csv' that are related to spatially 
distributed event characteristics (precipitation amounts, drought indicators,
etc.) were derived from PRISM 4-km gridded data products (PRISM Climate Group,
2023) and summarized for each event as the spatial mean of the characteristic
in question across each HUC 8 subbasin in the KSRB. Thus, each of these event
characteristics are spread across many columns in the .csv, one for each HUC 8,
and can be identified by the presence of an 8-digit HUC ID string in the column
name. See the variable descriptions below for further details on these.


Variable Descriptions:

FI_n: Flushing Index for nitrate concentrations. Measures degree of nitrate
enrichment or dilution during the rising limb of the event. Ranges from -1
to +1. See Vaughan et al. (2017) for formula and details.

HI_n: Hysteresis Index for nitrate concentrations. Measures degree of
clockwise/counterclockwise hysteresis in the nitrate C-Q loop. Ranges from
-1 to +1. See Vaughan et al. (2017) for formula and details.

start_dateTime, end_dateTime: Start and end times of the flow event.

wateryear: Water year at the start of the event. Water years begin in October
of the preceding calendar year, so October 2013 is the first month of the 2014
water year.

month, season: Month and season at the start of the event. Winter = Dec - Feb, 
Spring = Mar - May, Summer = Jun - Aug, Fall = Sep - Nov.

yday: Julian day at the start of the event.

duration: Duration of event from start to end in days.

duration_since_last: Duration from start of event to end of preceding event in 
days.

{statistic}_Q: Statistics on discharge, in m^3/s unless otherwise noted.

	statistics: 
		initial = discharge at event start
		max = maximum discharge during event
		delta = maximum discharge minus initial discharge
		delta_rat = ratio of delta discharge to initial discharge
		total = summed discharge over entire course of event [in m^3]

{statistic}_N: Statistics on nitrate concentrations, in mg/L as N unless
otherwise noted.

	statistics: 
		initial = concentration at event start
		max = maximum concentration during event 
		min  = minimum concentration during event
		delta = maximum minus minimum concentration 
		total = summed nitrate load over entire course of event [in kg]

p_{huc8}_{variable}: Characteristics related to precipitation, summarized as
the spatial mean across each of the 43 HUC 8s in the KSRB. Measured in mm.

	huc8s: Delineated in 'huc8_boundaries.shp'
	
	variables:
		1d_total = total amount of precipitation that fell during the event and within
		1 day prior to the event (to account for travel time through the basin)

		{window}_ante = total amount of precipitation that fell within the given
		window length prior to the start of the event  

			windows = 7, 15, 30, 60, 90, 180, 270, and 365 days

d_{huc8}_spei{timescale}: Standardized Precipitation Evapotranspiration Index
averaged across each of the 43 HUC 8s in the KSRB for various timescales. Gives
the drought status of the measured area on a normalized scale, where positive
values indicate wetter-than-normal conditions and negative values indicate
drier-than-normal conditions (in standard deviations) over the calculated 
timescale. See Vicente-Serrano et al. (2010) for more details.

	huc8s: Delineated in 'huc8_boundaries.shp'

	timescales: 1, 3, 6, 9, 12, 18, and 24 months

r_{reservoir}_{variable}: Characteristics related to reservoir outflows for
each of the 7 major reservoirs operated in the KSRB. All outflow data obtained
from USGS gages immediately downstream (< 10 km in all cases) of the reservoir
outflow points.

	reservoirs: Delineated in 'reservoirs.shp'
		t = Tuttle Creek Lake (gage #06887000)
		m = Milford Lake (gage #06857100)
		p = Perry Lake (gage #06890900)
		c = Clinton Lake (gage #06891500)
		k = Kanopolis Lake (gage #06865500)
		wi = Wilson Lake (gage #06868200)
		wa = Waconda Lake (gage #06875900)
		sum = Summed across all 7 reservoirs

	variables:
		1d_total = total outflow (in m^3) from the reservoir that occurred during the
		event, including a 1-day window prior to the event start and exluding a 1-day
		window prior to the event end to account for water travel times from the
		reservoirs to the outlet gage.

		share = 1d_total outflow divided by the event total runoff (column total_Q)
		to give a measure of the proportion of the event's total runoff that is
		comprised of outflows from the reservoir.