Douglas A. Burns
20160311
Patterns of Diel Variation in Nitrate Concentrations in the Potomac River
comma delimited text
Reston, VA
U.S. Geological Survey
http://dx.doi.org/10.5066/F7HT2MD4
This data set includes nitrate concentration, water temperature, and discharge collected every 15 minutes during Dec. 2011 - Nov. 2013 from the USGS gage at the Potomac River near Wash, DC, Little Falls Pump Sta (01646500). Additional data includes day length from the US Naval Observatory, and photosynthetically active radiation from USDA research station in Beltsville, MD. Data on channel width and velocity based on manual discharge measurements made at the USGS gage at the Potomac River at Point of Rocks, MD (01638500) are included and were applied to calculate diel nitrate loss rates. Several calculations derived from these data are included in the data set. These data accompany a paper titled "Patterns of Diel Variation in Nitrate Concentrations in the Potomac River", and details about further calculations and summaries based on these data are described in the manuscript.
Data were obtained and calculations were made to estimate nitrate losses associated with diel variation in nitrate concentrations in the Potomac River.
20111201
20131130
observed
As needed
-79.748442
-76.875158
40.262728
37.783658
None
nitrogen
nitrate
diel variation
in-stream processes
river
USGS Metadata Identifier
USGS:570b99fce4b0ef3b7ca0257d
None
Potomac River
Chesapeake Bay
none
none
Douglas Burns
U.S. Geological Survey
mailing and physical
425 Jordan Rd.
Troy
NY
12180
USA
518-285-5662
daburns@usgs.gov
USGS National Water Quality Program
Discharge and water temperature data were approved following standard USGS quality assurance protocols. Nitrate concentrations were finalized after following quality assurance protocols described in: Pellerin, B. A., B. A. Bergamaschi, B. D. Downing, J. F. Saraceno, J. A. Garrett, and L.D. Olsen. 2013. Optical techniques for the determination of nitrate in environmental waters: Guidelines for instrument selection, operation, deployment, maintenance, quality assurance, and data reporting. U.S. Geological Survey Techniques and Methods 1–D5, Reston, VA. No formal quality assurance was performed on the PAR data.
Values fall within expected ranges.
Data set is considered complete for the information presented, as described in the manuscript that is based on analyses of these data. Users are advised to read the rest of the metadata record carefully for additional details.
No formal positional accuracy tests were conducted
No formal positional accuracy tests were conducted
The data processing steps for each of the 10 data files are described in the Entity & Attributes and in the accompanying manuscript.
20151231
This dataset includes nitrate and discharge collected every 15 min. at the Potomac River streamgage at the Little Falls Pump Sta. Also included are calculations of loss of nitrate concentrations and loads that were attributed to diel variation as described in the manuscript.
Column A = Date and time, mm/dd/yyyy, hh:mm
Column B = Q, discharge, ft3/s
Column C = Q, discharge, m3/s
Column D = NO3, nitrate concentration, mg/L as N
Column E = Max interp line, nitrate concentration, mg/L as N, represents line that connects daily maximum values of deviation from Loess smooth (Loess smooth calculated by SigmaPlot software (v. 13) as described in manuscript)
Column F = NO3 load, g/s, calculated as column C * column D
Column G = Max NO3 load, g/s, calculated as column C * column E
Column H = NO3 conc diff, mg/L as N, calculated as column E - column D
Column I = NO3 load diff, g/s, calculated as column G - column F
Column J = NO3 conc diff frac, fraction, calculated as column H/column E
Column K = NO3 load diff frac, fraction, caclulated as column I/column G
Column L = Z score, standardized score, calculated as (Adj Loess diff - daily mean Adj Loess diff)/daily standard deviation Adj Loess diff
Column M = Loess smooth, mg/L as N, Loess smooth line fit to nitrate data
Column N = Adj Loess diff, mg/L as N, calculated as column M - column D
Column O = Cum NO3 conc, mg/L as N, calculated as the sum of column D for each day
Column P = Cum NO3 max conc, mg/L as N, calculated as the sum of column E for each day
Column Q = Cum NO3 diff, mg/L as N, calculated as column P - column O
Column R = Frac NO3 conc diff, fraction, calculated as column Q/column P
Column S = Cum NO3 load, g/s, calculated as the sum of column F for each day
Column T = Cum NO3 max load, g/s, calculated as the sum of column G for each day
Column U = Cum NO3 load diff, g/s, calculated as column T - column S
Column V = Frac NO3 load diff, fraction, calculated as column U/column T
Column W = Max NO3 conc diff, mg/L as N, the maximum value in column H for each day
Column X = Frac NO3 max load diff, fraction, the maximum value in column K for each day
Fifteen Minute Nitrate Calculations.csv
Data modified from source Little Falls Final NWIS Data.csv
Dataset of photosynthetically active radiation used to explore the potential role of solar radiation in diel variation of nitrate concentrations in the Potomac River.
Column A = Date, mm/dd/yyyy
Column B = Time, hh:mm
Column C = PAR, photosynthetically active radiation, micromol/s/m2, calculated by averaging data collected every 3 min.
Beltsville USDA PAR Data Set.csv
Source: http://uvb.nrel.colostate.edu/UVB/da_queryPar.jsf
Days with excessive missing nitrate data and during high flow when diel variation could not be quantified were removed prior to analysis
Column A = Agency, collection agency, USGS
Column B = Site ID, USGS National Water Information System Site ID for Little Falls gage, 01646500
Column C = Date, mm/dd/yyyy
Column D = Time, hh:mm
Column E = Time Std, time standard, Eastern Standard Time
Column F = NWIS NO3, mg/L as N, data from NWIS
Column G = NO3 post QA-QC, mg/L as N, data after applying quality assurance and quality control procedures
Column H = NO3 after linear interp and moving avg, mg/L as N, linear interpolation was applied to fill in short segments of missing data, 5 window moving average was applied to reduce noise in data series
Little Falls After Days Removed Data Set.csv
Data modified from source Little Falls Post-QA-QC Dataset.csv
Time of sunrise and sunset, and day length data used to explore the potential role of daylight patterns in diel variation in nitrate concentrations in the Potomac River.
Column A = Date, mm/dd/yyyy
Column B = Sunrise, hh:mm:ss
Column C = Sunset, hh:mm:ss
Column D = Day Length, hh:mm:ss, calculated as column C - column B
Little Falls Day Length Data Set.csv
Source: U.S. Naval Observatory, http://aa.usno.navy.mil/data/docs/RS_OneYear.php
Dataset that includes discharge, nitrate, and water temp. collected at the Potomac River at Little Falls Pump Sta streamgage during Dec. 2011 - Nov. 2013
Column A = agency_cd, USGS
Column B = site_no, 1646500
Column C = datetime, mm/dd/yyyy hh:mm
Column D = tz_cd, EST, Eastern Standard Time
Column E = 01_0060, Discharge, ft3/s
Column F = 01_0060_cd, Approval code, Approved or Provisional
Column G = 05_0010, Water temp, 4.1 ft from riverbed (middle), deg C
Column H = 05_0010_cd, Approval code, Approved or Provisional
Column I = 06_0010, Water temp 1.0 ft from riverbed (bottom), deg C
Column J = 06_0010_cd, Approval code, Approved or Provisional
Column K = 07_0010, Water temp, 7.1 ft from riverbed (top), deg C
Column L = Approval code, Approved or Provisional
Column M = 10_99133, nitrate plus nitrite concentration, mg/L as N
Column N = 10_99133_cd, Approval code, Approved or Provisional
Little Falls Final NWIS Data.csv
Source: http://waterdata.usgs.gov/usa/nwis/uv?01646500
Dataset shows original nitrate concentrations from NWIS, nitrate concentrations after QA-QC checks were made resulting in changes, and nitrate concentrations after linear interpolation was applied to fill-in small amounts of missing data, and a 5-sample moving average was applied to smooth measurement noise
Column A = Agency, USGS
Column B = Site ID, 1646500
Column C = Date, mm/dd/yyyy
Column D = Time, hh:mm
Column E = Time Std, EST, Eastern Standard Time
Column F = NWIS NO3, nitrate concentrations mg/L as N from USGS NIWS database
Column G = NO3 post QA/QC, nitrate concentrations mg/L as N after QA/QC checks
Column H = NO3 after linear interp and moving avg, nitrate concentrations mg/L as N after linear interpolation and a 5-sample moving average were applied
Little Falls Post-QA-QC Dataset.csv
Data modified from source Little Fall Final NWIS Data.csv
Dataset represents the results of a two-component hydrograph separation of mean daily discharge values from the Potomac River at Little Fall Pump Sta streamgage. These values were separated into direct runoff and baseflow using a one-parameter digital filter approach. These data were applied to assist in the determination of which days were sufficiently unimpacted by storm runoff to allow for an analysis of diel nitrate variation.
Little Falls Hydrograph Separation Results.csv
Source: https://engineering.purdue.edu/what/
Based on flow measurements from the Potomac River at Point of Rocks gage. Measurements were removed from the original data set if either: (1) mean width, mean depth, or discharge values were not available, or (2) the discharge value was outside the range of values at Little Falls that were used in the diel analysis.
Column A = NWIS Site, 1638500
Column B = Measurement No., sequential measurement number identifier
Column C = Measurement Date, mm/dd/yyyy
Column D = Discharge, ft3/s
Column E = Width, ft
Column F = Cross-Sectional Area, ft2
Column G = Mean Velocity, ft/s
Column H = Mean Depth, ft.
Column I = Discharge m3/s
Column J = Width, m
Column K = Cross-Sectional Area, m2
Column L = Mean Velocity, m/s
Column M = Mean Depth, m
Point of Rocks Manual Discharge Data.csv
http://waterdata.usgs.gov/nwis/measurements/?site_no=01638500
Column A = Date, mm/dd/yyyy
Column B = Season, fall, winter, spring, summer
Column C = Q, discharge, m3/s
Column D = Q, discharge, m3/15 min
Column E = Nitrate, concentrations mg/L as N
Column F = Width, m
Column G = Velocity, m/s
Column H = Velocity, m/15min
Column I = One Day Travel Time, km, calculated as (Column H * 96/1000)
Column J = Depth, m
Column K = NO3 diel, cum daily diff mg/L as N
Column L = NO3 Loss Rate, mg/m2/d, calculated as Column D/(Column F * Column H) * Column K* 1000
Potomac Nitrate Loss Rates.csv
Data set represents calculations based on data obtained from files Little Falls After Days Removed Data Set.csv and Point of Rocks Manual Discharge Data.csv.
Column A = Date, mm/dd/yyyy
Column B = Season, winter, spring, summer, fall
Column C = Q, m3/s
Column D = QBF, m3/s, baseflow discharge from hydrograph separation
Column E = BFI, fraction, Base Flow Index, calculated as Column D/Column C
Column F = [NO3]meas, daily mean concentration, mg/L as N
Column G = [NO3]GWD, mg/L as N in groundwater discharge, calculated from winter regression NO3 vs BFI
Column H = [NO3]RO, mg/L as N in runoff, calculated from winter regression NO3 vs BFI
Column I = [NO3]IN, mg/L as N, calculated (Column E*Column G) + ((1-Column E)*Column H)
Column J = [NO3]diff, mg/L as N, calculated as Column I - Column F
Column K = Loss Frac, fraction, calculated as Column J/Column I
Total In-Stream Nitrate Loss.csv
Data set represents calculations based on data obtained from file Potomac Nitrate Loss Rates.csv
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The data you have secured from the U.S. Geological Survey (USGS) database identified as Dataset to accompany the paper titled, "Patterns of Diel Variation in Nitrate Concentrations in the Potomac River" have not received USGS approval and as such are provisional and subject to revision. The data are released on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein.
20220908
gs-wma-impd-mdmf
U.S. Geological Survey
Research Hydrologist
mailing and physical
425 Jordan Rd.
Troy
NY
12180
USA
518-285-5662
doi-mdmf@doimspp.onmicrosoft.com
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998