This codebook.txt file was generated on 20180320 by Amy Hansen ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset Gap-filled USGS sensor data for nitrate, discharge and temperature for selected sites in Iowa, U.S.A., 2012-2017 2. Author Information Principal Investigator Contact Information Name: Amy Hansen Institution: University of Minnesota Address: Minneapolis, Minnesota Email: hanse782@umn.edu Associate or Co-investigator Contact Information Name: Arvind Singh Institution: University of Central Florida Address: Orlando, Florida Email: Arvind.Singh@ucf.edu 3. Date of data collection: 2012 - 2017 4. Geographic location of data collection: Eight watersheds primarily located in Iowa. 5. Information about funding sources that supported the collection of the data: National Science Foundation under Grant EAR-1415206 Science, Engineering and Education for Sustainability (SEES) Fellows to A.T.H.: SEES Fellows: Leveraging the waterscape to increase agricultural landscape sustainability. Donor of American Chemical Society Petroleum Research Fund to A.S. -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: CC0 1.0 Universal 2. Links to publications that cite or use the data: Citing publication is in revision. Hansen, A.T., A. Singh (in revision). Extracting watershed scale biogeochemistry from high frequency sensor data in intensively managed agricultural basins, Journal of Geophysical Research – Biogeosciences. 3. Links to other publicly accessible locations of the data: Raw data is available at http://waterdata.usgs.gov/nwis 4. Links/relationships to ancillary data sets: None. 5. Was data derived from another source? Yes. Gap filled data was derived from raw data. Both are provided. 6. Recommended citation for the data: Hansen, Amy, T.; Singh, A.. (2018). Gap-filled USGS sensor data for nitrate, discharge and temperature for selected sites in Iowa, U.S.A., 2012-2017. Retrieved from the Data Repository for the University of Minnesota --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: GapFill_5455100_OldMansCreek.txt Short description: Gapfilled time series data from Old Mans Creek USGS siteID 5455100 B. Filename: Raw_5455100_OldMansCreek.txt Short description: Raw time series data from Old Mans Creek USGS siteID 5455100 C. Filename: GapFill_5481000_BooneRiver.txt Short description: Gapfilled time series data from Boone River USGS site ID 5481000 D. Filename: Raw_5481000_BooneRiver.txt Short description: Raw time series data from Boone River USGS site ID 5481000 E. Filename: GapFill_5464420_CedarRiver.txt Short description: Gapfilled time series data from Cedar River USGS site ID 5464420 F. Filename: Raw_5464420_CedarRiver.txt Short description: Raw time series data from Cedar River USGS site ID 5464420 G. Filename: GapFill_5482000_Des MoinesRiver.txt Short description: Gapfilled time series data from Des Moines River USGS site ID 5482000 H. Filename: Raw_5482000_Des MoinesRiver.txt Short description: Raw time series data from Des Moines River USGS site ID 5482000 I. Filename: GapFill_5465500_IowaRiver.txt Short description: Gapfilled time series data from Iowa River USGS site ID 5465500 J. Filename: Raw_5465500_IowaRiver.txt Short description: Raw time series data from Iowa River USGS site ID 5465500 K. Filename: GapFill_5482500_N_RaccoonRiver_Jefferson.txt Short description: Gapfilled time series data from North Raccoon River at Jefferson USGS site ID 5482500 L. Filename: Raw_5482500_N_RaccoonRiver_Jefferson.txt Short description: Raw time series data from North Raccoon River at Jefferson USGS site ID 5482500 M. Filename: GapFill_5482300_N_RaccoonRiver_SacCity.txt Short description: Gapfilled time series data from North Raccoon River at Sac City USGS site ID 5482300 N. Filename: Raw_5482300_N_RaccoonRiver_SacCity.txt Short description: Raw time series data from North Raccoon River at Sac City USGS site ID 5482300 O. Filename: GapFill_5484500_RaccoonRiver_VanMeter.txt Short description: Gapfilled time series data from Raccoon River at Van Meter USGS site ID 5484500 P. Filename: Raw_5484500_RaccoonRiver_VanMeter.txt Short description: Raw time series data from Raccoon River at Van Meter USGS site ID 5484500 2. Relationship between files: Files with names beginning in "GapFill" were generated using Auto Regressive model (Matlab function 'fillgaps') on time series files labeled "Raw" for each site. This function is available in Matlab R2017a. We used an averaging window of approximately 20 data points, corresponding to 5 hours. 3. Additional related data collected that was not included in the current data package: None. 4. Are there multiple versions of the dataset? No -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: We used publically available high-frequency sensor data for this study collected by the United States Geologic Survey (USGS).All sensors were installed and operated by USGS who maintains an extensive network of real time sensors. Nitrate sensors at each site were fixed optical sensors with 2 mm path length, with the exception of the Raccoon River at Van Meter site which has a 5 mm path length (Hach Nitratax plus sc Sensor, Loveland, CO, USA). Sensor data for nitrate was validated against traditional chemical measures of nitrate concentration by USGS personnel and following USGS protocol [Wagner et al., 2006; Pellerin et al., 2013]. Nitrate sensor measurements corresponded to nitrate plus nitrite as nitrogen with an accuracy of the greater of +/- 3% of measured value or 0.5 mg/L. Discharge, NO3-, and temperature sensors were co-located at each site and sensor data consisted of measurements collected at a 15 minute interval over a period of approximately five years from 2012 to 2017. Wagner, R., R. Boulger, Jr., C. Oblinger, and B. Smith (2006), Guidelines and standard procedures for continuous water-quality monitors: station operation, record computation, and data reporting: U.S. Geological Survey Techniques and Methods 1–D3. Pellerin, B. A., B. A. Bergamaschi, B. D. Downing, J. F. Saraceno, J. D. 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. 2. Methods for processing the data: Files with names beginning in "GapFill" were generated using Auto Regressive model (Matlab function 'fillgaps') on time series files labeled "Raw" for each site. This function is available in Matlab R2017a. We used an averaging window of approximately 20 data points, corresponding to 5 hours. 3. Instrument- or software-specific information needed to interpret the data: N/A. 4. Standards and calibration information, if appropriate: See References provided above. 5. Environmental/experimental conditions: N/A. 6. Describe any quality-assurance procedures performed on the data: See References provided above. 7. People involved with sample collection, processing, analysis and/or submission: Amy Hansen and Arvind Singh ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: ALL FILES ----------------------------------------- 1. Number of variables: 5 2. Missing data codes: NaN No data available 3. Variable List A. Name: M_Date Description: Date and time of data collection in Matlab numeric format B. Name: DateTime Description: Date and time of data collection in format MM/DD/YYYY HH:MM C. Name: Q_cfs Description: Water discharge reported in cubic feet per second. D. Name: NO3_mgL Description: Concentration of nitrate+nitrite in the form of nitrogen reported in mg/L. E. Name: T_degC Description: Water temperature reported in degrees Celcius. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Individual Files ----------------------------------------- A. Filename: GapFill_5455100_OldMansCreek.txt 1. Number of cases/rows: 136493 B. Filename: Raw_5455100_OldMansCreek.txt 1. Number of cases/rows: 136493 C. Filename: GapFill_5481000_BooneRiver.txt 1. Number of cases/rows: 172456 D. Filename: Raw_5481000_BooneRiver.txt 1. Number of cases/rows: 172456 E. Filename: GapFill_5464420_CedarRiver.txt 1. Number of cases/rows: 125336 F. Filename: Raw_5464420_CedarRiver.txt 1. Number of cases/rows: 125336 G. Filename: GapFill_5482000_Des MoinesRiver.txt 1. Number of cases/rows: 119833 H. Filename: Raw_5482000_Des MoinesRiver.txt 1. Number of cases/rows: 119833 I. Filename: GapFill_5465500_IowaRiver.txt 1. Number of cases/rows: 232583 J. Filename: Raw_5465500_IowaRiver.txt 1. Number of cases/rows: 232583 K. Filename: GapFill_5482500_N_RaccoonRiver_Jefferson.txt 1. Number of cases/rows: 275650 L. Filename: Raw_5482500_N_RaccoonRiver_Jefferson.txt 1. Number of cases/rows: 275650 M. Filename: GapFill_5482300_N_RaccoonRiver_SacCity.txt 1. Number of cases/rows: 286058 N. Filename: Raw_5482300_N_RaccoonRiver_SacCity.txt 1. Number of cases/rows: 286058 O. Filename: GapFill_5484500_RaccoonRiver_VanMeter.txt 1. Number of cases/rows: 165677 P. Filename: Raw_5484500_RaccoonRiver_VanMeter.txt 1. Number of cases/rows: 165677 Variables (Shared across all GapFill and Raw .txt files) A. Name: M_Date Description: Date and time of data collection in Matlab numeric format B. Name: DateTime Description: Date and time of data collection in format MM/DD/YYYY HH:MM C. Name: Q_cfs Description: Water discharge reported in cubic feet per second. D. Name: NO3_mgL Description: Concentration of nitrate+nitrite in the form of nitrogen reported in mg/L. E. Name: T_degC Description: Water temperature reported in degrees Celsius.