In general, discharge measurements were taken at a variety of stage heights throughout the summer using a Gurley meter, Marsh McBirney portable water current meter, or SonTek FlowTracker. A rating curve was developed to relate stage height to discharge, then this relationship was applied to stage height measurements taken throughout each summer to provide more frequent discharge measurements. In more recent years, dataloggers (e.g., Onset HOBO pressure transducers) were used to provide continuous stage data throughout the season. Starting in the 2010's, pressure transducers were also overwintered to attempt to capture fall and spring discharge. When usable data were available, stage from the winter staff gauge was related to what stage would have been on the summer staff gauge, so the summer rating curve could be applied to calculate discharge. Temperature was recorded by a variety of means over the years, including thermometer measurements, Campbell dataloggers, and HOBO pressure transducers.

Due to the evolution of measurement technology and miscellaneous measurement challenges (e.g., flood damaged sensors and staff gauges), the exact methods used for discharge and temperature measurement varied considerably over the course of this record. For a complete log of the methods used to produce this dataset, please reference the  section below.

NOTE FOR SPRING AND FALL DATA:
For consistency, data are reported from 5/1 through 10/31, when available; however, these dates should NOT be considered the start and end of flow. The pressure transducers do not fully thaw until after the onset of flow in spring, and likely freeze before the cessation of flow in the fall. Start and end of flow may be inferred by inspecting patterns in temperature and stage during these times. All data marked with the comment "WINTER" should be used with caution.

Arctic LTER streams protocols:

https://arc.lternet.edu/streams/arctic-lter-streams-protocol

Historic Discharge and Temperature Measurement Methods

Compiled by Frances Iannucci

August 2019

OKSRUKUYIK CREEK

1989: Stage height measurements taken at gauging station and discharge calculated from stage height by using a "stage/discharge relationship".

Temperature readings were taken daily with a 12" blunt stem reotemp dial-head thermometer at a location between the two culverts on the upstream side of the road.

Discharge data were acquired from the USGS in Fairbanks who use their gauging station on the creek to monitor stage height. More detailed methods of their Hydrologic Unit, calibration measurements and regression curve were not available at the time of this file. Discharge values, as mean daily discharge, were given in ft^3/sec and were converted by LTER staff to m^3/sec. See Oksrukuyik Creek 1988 Discharge paper file for more details.

1990: Discharge was measured using the velocity area method with a SonTek or Marsh-McBirney flowmeter.  Discharge was measured six times throughout the summer season.  Flow was measured at 20 points along a transect. A Campbell Scientific CR-10 datalogger recorded stage height every 4 hours.  The observed stage height is used with the measured discharge to develop a rating curve determined by the USGS. The rating curve is used to calculate discharge from the recorded stage height values.  

1991-1992: Stage height measurements taken at gauging station and discharge calculated from stage height by using a "stage/discharge relationship".

Notes: Oks Creek stage height data was acquired from the USGS in Fairbanks who use their gauging station on the creek to monitor the stage height. USGS stage height measurements are in feet and were converted to centimeters for further calculation. Discharge was calculated using the 1990 Oksrukuyik discharge rating curve. Discharge = 0.925305872956 + (-0.52412639055)stage + (0.000705907799)stage2 +(0.00000117057)stage3. Discharge was calculated for six stage height readings a day, taken at four hour intervals.

It should be noted that after the August 23 pulse there was a significant change in the channel at Oks Creek. Richard Kemnitz from the Fairbanks USGS thought that the channel had filled in approximately 0.5 feet at the low end and 0.3 feet at the high end. Therefore, the discharge calculations for August 23-25 may be as much as 30% too high. USGS took a discharge reading after the August 23rd pulse but the data are not yet available.

For further information on discharge calculations see the Oksrukuyik Creek 1988 and 1991 Discharge files.

Temperature readings were taken daily with a 12" blunt stem reotemp dial-head thermometer at a location between the two culverts on the upstream side of the road.

 In 1992, two rating curves were used to calculate discharge, one for low stage height and one for high stage height.

The rating curve equation to calculate discharge when stage height was less than 18.43 feet is Discharge = exp(a+bexp(x)) where a=-2.4379247, b=3.5955812e-08, and x=stage

The rating curve equation to calculate discharge when stage height was greater than 18.43 feet is Discharge = (a+bx^3) where a=-53.964473, b=0.0091870784, and x=stage.

1993: Stage height measurements were provided in 12-hour increments for most of the summer by the USGS Stevens chart recorder at the USGS gauging station, 10 meters downstream of the Dalton Highway crossing. Discharge measurements were taken by Deborah Repert and Nancy Parmentier using a Marsh-McBirney flow meter and a Teledyne-Gurley flow meter at a location 20 meters below the chart recorder. Flow was measured at 20 points for each transect. A total of 8 discharge measurements were used to calibrate the rating curves for this year.

Notes: For the rating curve, two separate curves were used according to the stage height. At stage heights less than 18.48 ft on the USGS gauging station, the curve has 5 points and is:

Discharge (m^3/s) = 2.2853e-88(x^69.147), where x = stage height in meters.

At stage heights greater than 18.48 ft on the gauging station, the curve has four points and is:

Discharge (m^3/s) = 7.9921e-35(x^26.891), where x = stage height in meters.

Temperature readings were taken daily with a 12" blunt stem reotemp dial-head thermometer at a location between the two culverts on the upstream side of the road.

1994: Stage height measurements were taken hourly with a Campbell CR-10 datalogger, and continuously with the USGS Stevens chart recorder, at the USGS gauging station, 10 meters downstream of the  Dalton Highway crossing. Discharge measurements were taken by Chris Harvey using a Marsh-McBirney flow meter and a Teledyne-Gurley flow meter at a location 20 meters below the chart recorder. Flow was measured at 20 points for each transect. A total of 8 discharge measurements were used to calibrate the rating curves for this year.

Temperature readings were taken hourly by a Campbell CR-10 datalogger located 10 m downstream from the Oksrukuyik Creek crossing of the Dalton Highway.

Notes: The high water event that occurred on July 31 caused Oksrukuyik Creek to overflow its banks for several days. The stage height during this time was far beyond the greatest stage height at which a manual discharge measurement was taken with a flow meter. Therefore, the discharge estimates during this event may be inaccurate. This event, however, represents only a small fraction of the total discharge profile for the season.

The USGS Stevens chart recorder data are not used in this dataset.

The rating curve equation used to calculate discharge is discharge = a(x^b) where a=1.314e-10, b=5.0551, and x=stage height in meters

1995: Stage height measurements were taken hourly with a Campbell CR-10 datalogger, and continuously with the USGS Stevens chart recorder, at the USGS gauging station, 10 meters downstream of the Dalton Highway crossing. Discharge measurements were taken by Chris Harvey and Kim Hageman using a Marsh-McBirney flow meter and a Teledyne-Gurley flow meter at a location 20 meters below the chart recorder. Flow was measured at 20 points for each transect. A total of 8 discharge measurements were used to calibrate the rating curves for this year.

The rating curve equation used to calculate discharge is Discharge = a(x^b) where a=2.2491e-07, b=3.5465, and x=stage height in meters

Temperature readings were taken by a Campbell CR-10 datalogger located 10 m downstream from the Oksrukuyik Creek crossing of the Dalton Highway.

1996: Stage height measurements were taken hourly with a Campbell cR-10 datalogger, and continuously with the USGS Stevens chart recorder, at the USGS gauging station, 10 meters downstream of the Dalton Highway crossing. Discharge measurements were taken by Chris Harvey and Karie Slavik using a Teledyne-Gurley flow meter at a location 20 meters below the chart recorder. Flow was measured at 20 points for each transect. A total of 8 discharge measurements were used to calibrate the rating curves for this year.

The rating curve equation was Discharge= a(x^b), where a=5.429e-10, b=4.778, and x=stage height in meters

Temperature readings were taken hourly with the Campbell CR-10 datalogger.

1997: Stage height measurements and temperature were taken half hourly with a Campbell CR-10 datalogger, and continuously with the USGS Stevens chart recorder, at the USGS gauging station, 10 meters downstream of the Dalton Highway crossing. Discharge measurements were taken by Kaire Slavik and Nat Weston using a Marsh-McBirney flow meter at a location 20 meters below the chart recorder. Flow was measured at 20 points for each transect. A total of 8 discharge measurements were used to calibrate the rating curve for this year.

IMPORTANT: Logger data is 1 day (exactly 24 hours) behind the real date listed.

The rating curve equation used to calculate discharge was Discharge = a(x^b), where a=2e-10, b=4.9026 and x=stage height in meters

1998: Stage height measurements were taken every ten minutes with a Campbell CR-10 datalogger, and continuously with the USGS Stevens chart recorder, at the USGS gauging station, 10 meters downstream of the Dalton Highway crossing. Discharge measurements were taken by Karie Slavik, Nia Pauliukonis and Stephanie Parker using a Marsh McBirney flow meter at a location 20 meters below the chart recorder. Flow was measured at least 20 points for each transect. A total of 8 discharge measurements were used to calibrate the rating curves for this year.

The rating curve used to calculate discharge is Discharge = a(x^b), where a=9.0e-19, b=8.8625, x=stage height in meters

Temperature readings were taken by a Campbell CR-10 datalogger located 10 m downstream from the Oksrukuyik Creek crossing of the Dalton Highway.

1999: Stage height measurements were taken hourly with a Campbell CR-10 datalogger, and continuously with the USGS Sevens chart recorder, at the USGS gauging station, 10 meters downstream of the Dalton Highway crossing. Discharge measurements were taken by Karie Slavik and Stephanie Parker using a Marsh McBirney flow meter at a location 20 meters below the chart recorder. Flow was measured at 20 points for each transect. A total of 7 discharge measurements were used to calibrate the rating curves for this year.

The rating curve equation used to calculate discharge is Discharge=a(x^b) where a=1e-11, b=5.3988, x=stage height in meters

Temperature readings were taken every 10 minutes by a Campbell CR-10 datalogger located 10 m downstream from the Oksrukuyik Creek crossing of the Dalton Highway.

2000: Stage height measurements and temperature readings were taken every ten minutes with a Campbell CR-10 datalogger, at the USGS gauging station, 10 meters downstream of the Dalton Highway crossing. Discharge measurements were taken by Karie Slavik and Jon O'Donnell using a Marsh McBirney flow meter at a location 20 meters below the chart recorder. Flow was measured at 20 points for each transect. A total of 7 discharge measurements were used to calibrate the rating curves for this year.

The rating curve equation to calculate discharge is Discharge = a(x^b) where a=2e-13, b=6.2331, and x=stage height in meters.

2001: Stage height measurements and temperature readings were taken every ten minutes with a Campbell CR-10 datalogger, at the USGS gauging station, 10 meters downstream of the Dalton Highway crossing. Discharge measurements were taken by Karie Slavik and Jon O'Donnell using a Marsh McBirney flow meter at a location 20 meters below the chart recorder. Flow was measured at 20 points for each transect. A total of 7 discharge measurements were used to calibrate the rating curves for this year.

The rating curve equation to calculate discharge is Discharge = a(x^b) where a=5e-10, b=4.7637, and x=stage height in meters.

2002: Stage height measurements were taken every ten minutes with a Campbell CR-10 datalogger, at the USGS gauging station, 10 meters downstream of the Dalton Highway crossing. Discharge measurements were taken by Adrian Green and Kevin Barnes using a Marsh McBirney flow meter at a location 20 meters below the chart recorder. Flow was measured at 20 points for each transect. A total of 6 discharge measurements were used to calibrate the rating curves for this year.

The rating curve equation used to calculate discharge is Discharge = a(x^b) where a=3e-13, b=6.23, and x=stage height in centimeters.

2003: Stage height measurements and temperature readings were taken every ten minutes with a Campbell CR-10 datalogger, at the USGS gauging station, 10 meters downstream of the Dalton Highway crossing. Discharge measurements were taken by Adrian Green and Jeff Ziegeweid using a Marsh McBirney flow meter at a location 20 meters below the chart recorder. Flow was measured at 20 points for each transect. A total of 7 discharge measurements were used to calibrate the rating curves for this year.

The rating curve equation to calculate discharge was Discharge = a(x^b) where a=3e-15, b=7.1812, and x=stage height in centimeters

2004: Discharge was measured using the velocity area method with a Marsh-McBirney flowmeter. Discharge was measured seven times throughout the summer season. Flow was measured at 20 points along a transect. A Campbell Scientific CR-10 datalogger was installed on 18 June 2004 and removed on 12 August 2004 to record stage height and water temperature every 10 minutes. The observed stage height is used with the measured discharge to develop a rating curve. The rating curve is used to calculate discharge from the recorded stage height values. 68.688928 -149.094342

The rating curve equation for calculating discharge is discharge=mx^b where m=8e-17, b=8.7384, and x=stage height in cm

2005: Discharge was measured using the velocity area method with a SonTek FlowTracker or Marsh-McBirney FloMate. Discharge was measured five times throughout the summer season. Flow was measured at 20 points along a transect. A Campbell Scientific CR-10 datalogger was installed on 28 June 2005 and removed 10 August 2005. The datalogger recorded stage height and temperature every 10 minutes. The observed stage height is used with the measured discharge to develop a rating curve. The rating curve is used to calculate discharge from the recorded stage height values.

The rating curve equation used to calculate discharge from stage height was discharge=mx^b, where m=8.09e-7, b=3.5588, and x=stage height in cm.

2006: Discharge was measured using the velocity area method with a SonTek or Marsh-McBirney flowmeter.  Discharge was measured five times throughout the summer season.  Flow was measured at 20 points along a transect. A Campbell Scientific CR-10 datalogger recorded stage height and temperature every ten minutes.  The observed stage height is used with the measured discharge to develop a rating curve (y=0.0688x-2.1286). The rating curve is used to calculate discharge from the recorded stage height values. A Campbell Scientific CR10 datalogger was installed on 08Jun06 and removed on 15Aug06.

2007: Discharge was measured using the velocity area method with a SonTek or Marsh-McBirney flowmeter.  Discharge was measured eight times throughout the summer season.  Flow was measured at 20 points along a transect. A Campbell Scientific CR10 datalogger was installed about 10m downstream of the Dalton Highway crossing on 14Jun07 and removed on 09Aug07. It was located about 10m downstream of the Dalton Highway crossing. The datalogger recorded stage height and temperature every ten minutes.  The observed stage height is used with the measured discharge to develop a rating curve (y=5e+35x50.375). The rating curve is used to calculate discharge from the recorded stage height values.

2008: Discharge was measured using the velocity area method with a SonTek or Marsh-McBirney flowmeter.  Discharge was measured six times throughout the summer season.  Flow was measured at 20 points along a transect. A Campbell Scientific CR-10 datalogger recorded stage height every ten minutes.  The observed stage height is used with the measured discharge to develop a rating curve (y=4e-13x6.7354). The rating curve is used to calculate discharge from the recorded stage height values. A Campbell Scientific CR10 datalogger was installed on 24Jul08 and removed on 06Aug08. The datalogger recorded temperature every 10 minutes. It was located about 10m downstream of the Dalton Highway crossing.

2009: Discharge was measured using the velocity area method with a SonTek flowmeter.  Discharge was measured eight times throughout the summer season.  Flow was measured at 20 points along a transect. This year two instruments were used to measure stage height and temperature, a Campbell Scientific CR-10X datalogger and a HOBO pressure transducer. The location was moved from previous years due to potential road construction on the culvert at the Dalton Highway crossing. Construction is now set to begin in the spring of 2010.   The Campbell Scientific CR10 datalogger was installed on 12 June 2009 and removed on 30 August 2009; the HOBO pressure transducer was installed 23 June 2009 and removed 12 August 2009. Each instrument recorded stage height and temperature every 10 minutes.  The observed stage height is used with the measured discharge to develop a rating curve. The rating curve is used to calculate discharge from the recorded stage height values.  The equation for the HOBO rating curve is y=5.758x - 1.9937, where x =stage height in meters and the equation for the CR-10 datalogger rating curve is y=6.717x - 1.6588, where x=stage height in feet. Rating curves were developed for both instruments to cross-compare.  The probes were at the same location, which is also where discharge was measured.

2010: Discharge was measured using the velocity area method with a SonTek flowmeter.  Discharge was measured six times throughout the summer season.  Flow was measured at 20 points along a transect. This year two instruments were used to measure stage height, a Campbell Scientific CR-10 datalogger and a HOBO pressure transducer.  The CR10X was installed on 17 June 2010 and removed on 8 August 2010, the HOBO was installed on 23 June 2010 and removed on 14 August 2010. Each instrument recorded stage height and temperature every 10 minutes.  The observed stage height is used with the measured discharge to develop a rating curve. The rating curve is used to calculate discharge from the recorded stage height values.  The equation for the HOBO rating curve is Q=9.6588x^2.7679 where x is stage height in meters and the equation for the CR-10 datalogger rating curve is Q=56.338x^5.4413, where x is the river stage in centimeters. Rating curves were developed for both instruments to cross-compare.  The location of the instruments and discharge measurement was moved in 2009 to the current location due to potential road construction on the culvert at the Dalton Highway crossing.

2011: Discharge was measured using the velocity area method with a SonTek flowmeter.  Discharge was measured six times throughout the summer season.  A HOBO pressure transducer was used to measure stage height.  HOBO was installed on 16 June 2011 and removed on 18 August 2011. Each instrument recorded stage height and temperature every 10 minutes.  The observed stage height is used with the measured discharge to develop a rating curve. The rating curve is used to calculate discharge from the recorded stage height values.  The equation for the HOBO rating curve is Q=1.8236x - 0.4266 where x is stage height in meters.  The location of the instruments and discharge measurement was moved in 2009 to the current location due to potential road construction on the culvert at the Dalton Highway crossing.

2012: Discharge was measured using the velocity area method with a SonTek flowmeter.  Discharge was measured six times throughout the summer season.  A HOBO pressure transducer was used to measure stage height, recording stage height and temperature every 10 minutes.  The observed stage height is used with the measured discharge to develop a rating curve. The rating curve is used to calculate discharge from the recorded stage height values.  The equation for the HOBO rating curve is Q=4.4296x^3.1567, where x is stage height in meters.  The location of the instruments and discharge measurement was moved in 2009 to the current location due to potential road construction on the culvert at the Dalton Highway crossing.

2013: Discharge was measured using the velocity area method with a SonTek flowmeter.  Discharge was measured six times throughout the summer season.  A HOBO pressure transducer was used to measure stage height.  HOBO was installed on 14 June 2013 and removed on 18 August 2013, recording stage height and temperature every 10 minutes.  The observed stage height is used with the measured discharge to develop a rating curve. The rating curve is used to calculate discharge from the recorded stage height values.  The equation for the HOBO rating curve is Q=4.3016x^2.5745 where x is stage height in meters.  The location of the instruments and discharge measurement was moved in 2009 to the current location due to potential road construction on the culvert at the Dalton Highway crossing.

2014: Discharge was measured using the velocity area method with a SonTek flowmeter in addition to a comparison of salt slug additions.   Discharge was measured 11 times throughout the summer season.  A HOBO pressure transducer was used to measure stage height. Both types of discharge measurements were fairly comparable, and during high discharge events when the stream was unsafe to enter, salt slug additions were used. The HOBO was installed on 13 June 2014 and removed on 18 August 2014. Each instrument recorded stage height and temperature every 10 minutes.  The observed stage height is used with the measured discharge to develop a rating curve. The rating curve is used to calculate discharge from the recorded stage height values.  The equation for the HOBO rating curve is Q=4.3659x^2.9297 where x is stage height in meters.  The location of the instruments and discharge measurement was moved in 2009 to the current location due to potential road construction on the culvert at the Dalton Highway crossing.

There was an issue with the pressure transducer deployed throughout the field season at this location. Luckily, there was a backup pressure transducer. However, this backup transducer became displaced several times throughout the field season because of large storm events. Therefore, the backup logger was compared to another logger that was about 3km upstream. The relationship between these two loggers was calculated, and QAQCed to develop this final product.

2015: Discharge was measured using the velocity area method with a SonTek flowmeter.  Discharge was measured 5 times throughout the summer season.  A HOBO pressure transducer was used to measure stage height. The HOBO was installed on 16 June 2015 and removed on 16 September 2015. Each instrument recorded stage height and temperature every 10 minutes.  The observed stage height is used with the measured discharge to develop a rating curve. The rating curve is used to calculate discharge from the recorded stage height values.  The equation for the HOBO rating curve is Q=22.028x^3.7476 where x is stage height in meters.  The location of the instruments and discharge measurement was moved in 2009 to the current location due to potential road construction on the culvert at the Dalton Highway crossing.

The HOBO that overwintered did not work in the spring. However, temperature data appeared okay during this time.

2016-2018: Discharge was measured using the velocity area method with a SonTek FlowTracker 6-8 times per season. A HOBO pressure transducer recorded continuous stage height and temperature at 10-minute intervals throughout each season. A rating curve is developed using discharge measurements and observed stage height, and this rating curve is applied to the continuous HOBO stage data to calculate a continuous discharge record. The location of the instruments and discharge measurement was moved in 2009 to the current location due to potential road construction on the culvert at the Dalton Highway crossing.

In 2018, the barometric pressure logger used for stage calculation was submerged during multiple high flow events in August and September. As a result, any discharge value greater than 15 m3/s is incorrectly calculated and should not be used. The barometric pressure logger was repositioned on September 6.