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. In years when WERC maintained the Kuparuk discharge record, high flow measurements were taken during spring freshet using an ADCP. 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. Temperature was recorded by a variety of means over the years, including thermometer measurements, Campbell dataloggers, and HOBO pressure transducers.
 

Protocols: See http://arc.lternet.edu/streams/arctic-lter-streams-protocol

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 below "Historic Discharge and Temperture Measurement Methods".

 NOTE: This file replaces the yearly files of discharge and temperatures.

Arctic LTER Streams

Historic Discharge and Temperature Measurement Methods

Compiled by Frances Iannucci

August 2019

 

This file is meant to serve as a supplement to the official LTER Streams discharge and temperature database. Discharge and temperature measurement technologies evolved frequently over the period of record, and various other equipment-related challenges influenced the calculation of discharge in individual years. This file documents the specific methods used for discharge and temperature measurement in all available years, as well as notes on any adjustments to discharge calculations within and between years.

All notes were compiled from the metadata of the annual discharge database files previously posted in the Arctic LTER database.

 

KUPARUK RIVER

1978-1980: Water flow was measured with a Gurley pygmy current meter during low flow and with the rhodamine dye dilution technique during high flows (95 m3 s-L). After the discharge- height relationship was known, we measured stream stage at the site where the haul road crosses the river and calculated discharge.

1983-1986: Discharge measurements were taken daily 1 km upstream of the Kuparuk River crossing at the Dalton Highway. Measurements were taken manually. It is unknown what type of sensor was used. It is also unknown what type of flow meter was used. 

Temperature data and stage height are not available for 1983-1984. Some temperature data are available for 1985-1986; however, not all sampling days have temperature measurements.

1987-1988: Stage height measurements were taken 1 km upstream of the Kuparuk River crossing at the Dalton Highway. Measurements were taken at the water line and recorded using a measuring stick placed vertically on the upstream side between the two culverts. The readings were in centimeters up from the bottom of the river. Additionally, a continuous record of stage height was maintained using a Stevens Water Level Recorder. The float for the gauge was housed in a stilling well constructed from a 12-inch diameter corrugated galvanized culvert pipe mounted vertically between the two culvert pipes on the upstream end. Measurements were taken every four hours.

Discharge was calculated from stage height. The calibration of the discharge regression equation was rechecked during the summer when the stage height was 130cm.  Actual flow measurements were taken at the “top, middle and bottom” depth increments every 1 meter along a cross sectional transect of the river, just downstream of the gas pipeline crossing. Calibration measurements were taken using a Marsh-McBirney, Model 201 portable water current meter. When the stage was under 105cm the rating curve equation y = ((x - 70)^1.44 * 0.016/2) + 0.1, with x as the stage height, was used. When the stage was over 105cm the rating curve equation y = ((x - 70)^1.44 * 0.016) + 0.1, with x as the stage height, was used. Raw data from the calibration measurement and the actual chart recordings are available.

Temperature data not available for 1987. Some temperature data are available for 1988. Temperature readings were taken with a 12” blunt stem reotemp dial-head thermometer at a location between the two culverts upstream of the road. 

1989: Stage height measurements were taken 1 km upstream of the Kuparuk River crossing at the Dalton Highway. Measurements were taken at the water line and recorded using a measuring stick placed vertically on the upstream side between the two culverts. The readings were in centimeters up from the bottom of the river. Measurements were taken daily.

Discharge was calculated from stage height. The calibration of the discharge regression equation was rechecked during the summer at three different stage heights, 88, 89.5 and 112cm.  Actual flow measurements were taken at the 10cm depth increments every 1 meter along a cross sectional transect of the river, just downstream of the gas pipeline crossing. Calibration measurements were taken using a Marsh-McBirney, Model 201 portable water current meter.

Due to the excessive 1989 spring break-up, the original stilling well and stage height measuring stick were washed away and lost. While a replacement measuring stick was positioned in the same location as the original, the zero point for the original stick was not recorded and it is unknown how the sticks correspond to one another with respect to their zero points. It is estimated that they were within 6cm of each other. The break-up also caused the section of the north culvert that was previously bent to bend further.

The three calibration values correspond fairly well to 1988’s regression curve when there is no change in slope of the curve at stage <105cm. Since there was minimal calibration data collected in 1989 due to the break-up, the discharge at all stage heights were calculated using the 1988 curve at a single slope (0.016). The rating curve equation used was y = ((x-70)^1.44 * 0.016) + 0.1), with x being the stage height.  Raw data from the calibration measurement are available.

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

1990: Stage height measurements were taken 1 km upstream of the Kuparuk River crossing at the Dalton Highway. From June 1, 1990 until June 23, 1990 measurements were taken daily. Beginning on June 24, 1990, measurements were taken every four hours. Measurements were taken at the water line and recorded using a measuring stick placed vertically on the upstream side between the two culverts. The readings were in centimeters up from the bottom of the river.

Discharge was calculated from stage height. The calibration of the discharge regression equation was rechecked during the summer at three different stage heights, 88, 89.5 and 112cm.  Actual flow measurements were taken at the 10cm depth increments every 1 meter along a cross sectional transect of the river, just downstream of the gas pipeline crossing. Calibration measurements were taken using a Marsh-McBirney, Model 201 portable water current meter.

The previous year, the stilling well and staff height measuring stick were washed out and lost due to an excessive spring break-up. While a replacement measuring stick was positioned in the same location as the original, the zero point for the original stick was not recorded and it is unknown how the sticks correspond to one another with respect to their zero points. It is estimated that they were within 6cm of each other. The 1989 break-up also caused the section of the north culvert that was previously bent to bend further.

The three calibration values correspond fairly well to 1988’s regression curve when there is no change in slope of the curve at stage <105cm. Discharge measurements at all stage heights were calculated using the 1988 curve at a single slope (0.016). The rating curve equation used was y = ((x-70)^1.44 * 0.016) + 0.1), with x being the stage height.  Raw data from the calibration measurement are available.

Water temperature readings were taken hourly by a Campbell datalogger positioned at the Kuparuk River Headwater Fork (68 33' 12"N;149 19' 30"W).

1991: Stage height measurements were taken daily 1 km upstream of the Kuparuk River crossing at the Dalton Highway. Measurements were taken at the water line and recorded using a measuring stick placed vertically on the upstream side between the two culverts. The readings were in centimeters up from the bottom of the river.

A new rating curve was developed from the 1990-1991 data, using six discharge measurements from 1990 and four discharge measurements from 1991. Discharge measurements taken in 1990 were found to be significantly different than those taken in 1991. Since it was uncertain that the 1990 numbers would provide sufficient information concerning the discrepancy between 1990 and 1991, the two years were plotted together using all ten measurements. The new rating curve used was y = -43.949081 + 1.569077x + (-0.018929)x^2+(0.000078294)x^3, with x as the stage height.

The percent error between measured discharges and those predicting using the new rating curve was between 22% at lower stage heights (80-100 cm) and 1% at higher stage heights (150 cm). The predicted values were found to be lower than the measured values.

Discharge measurements were taken using a Gurley meter. Calibration measurements were taken at 60% of depth at 0.5 meter increments along a cross sectional transect of the river, downstream of the culverts at the pipeline crossing. Raw data from calibration measurements are available.

Water temperature readings were taken hourly by a Campbell datalogger positioned at the Kuparuk River Headwater Fork (68 33' 12"N;149 19' 30"W).

1992: Stage height measurements were taken 1 km upstream of the Kuparuk River crossing at the Dalton Highway.  A Stevens Water Level Recorder with a float in a sitting well was used along with a pressure transducer to take a continuous record of stage height. Measurements were also taken at the water line from a measuring stick placed vertically on the upstream side between the two culverts. Readings on the measuring stick were in centimeters up from the bottom of the river. 

Discharge measurements were made using both a Marsh-McBirney 201 flow meter and a Gurney flow meter. Calibration measurements were at 60% of depth at 20-30 points along a cross sectional transect of the river, downstream of the culverts at the pipeline crossing. Raw data from calibration measurements are available.

Due to early June high waters, the standpipe from 1991 was washed out and one of the culverts was badly damaged. The resulting erosion and road washout from the flood altered the stream morphology. A new standpipe was installed in late June, but was also washed out on July 1st. On July 4th another standpipe was installed. The datalogger would normally supply missing data; however, the pressure transducer and the datalogger were both lost in floods. The pressure transducer was washed downstream and lost in the early June flood. The datalogger disappeared in the August 26 flood, prior to data collection. As a result, some data was lost.

Once again, a new discharge rating curve was developed for this year. The rating curve equation used was y = (-3.82 + 0.041*x )^2, with x as the stage height. Discharge was calculated for six stage height readings a day, taken at four hour intervals. Stage height was not accurately represented on the following days due to missing stage height data:

June 27 Only 1 reading - 1600 AST
June 28 No readings
June 29 No reading at 0000 and 0400
July 1 No reading at 2000
July 2 Only 1 reading - 1000
July 3 Only 2 readings - 0930 and 1200
July 4 No reading at 0000 and 0400
Aug 14 No reading at 1600 and 2000
Aug 15 Only 2 readings - 1600 and 2000

Breck Bowden performed some surveying at the Kuparuk road crossing to establish permanent reference marks and increase year to year continuity.

Temperature readings were taken daily  with a 12” blunt stem reotemp dial-head thermometer at a location between the two culverts upstream of the road.  There are several days with missing temperature data. There are also days where multiple temperature readings were taken.

1993-1996: Stage height measurements were recorded by a Campbell CR-10 datalogger positioned 1 km upstream of the Kuparuk River crossing at the Dalton Highway. Discharge was measured several times throughout the summer using a Teledyne-Gurley flow meter and wading rod. The stage height was measured at the time of discharge measurement. Continuous stage height readings collected on an hourly basis were then used to calculate continuous discharge using a rating curve for each summer. Temperature was also measured by a datalogger near this location. Discharge was calculated using stage levels measured by the Water and Environment Research Center using a rating curve that they developed.

More information about the methods and raw data can be found at: http://ine.uaf.edu/werc/projects/NorthSlope/upper_kuparuk/uk_river/uk_ri...

Kane, D.L. and Hinzman, L.D., 2013. Climate data from the North Slope Hydrology Research project. University of Alaska Fairbanks, Water and Environmental Research Center. URL: http://ine.uaf.edu/werc/projects/NorthSlope/ Fairbanks, Alaska, variously paged.

Raw data from the calibration measurements are available for 1995-1996.

1997-2013: Discharge was measured several times throughout the summer using a SonTek Flowtracker ADV and wading rod. The stage height was measured at the time of discharge measurement. Continuous stage height readings collected on an hourly basis were then used to calculate continuous discharge using a rating curve for each summer. Temperature was also measured by a datalogger near this location (specified as a HOBO sensor starting in 2000). Discharge was calculated using stage levels measured by the Water and Environment Research Center using a rating curve that they developed.

More information about the methods and raw data can be found at: http://ine.uaf.edu/werc/projects/NorthSlope/upper_kuparuk/uk_river/uk_ri...

Kane, D.L. and Hinzman, L.D., 2013. Climate data from the North Slope Hydrology Research project. University of Alaska Fairbanks, Water and Environmental Research Center. URL: http://ine.uaf.edu/werc/projects/NorthSlope/ Fairbanks, Alaska, variously paged.

Temperature data are not available for 1998.

Stage height data not included in the 2011 Q database file.

Temperature data are from the LTER Streams HOBO in 2012-2013, rather than WERC’s sensor.

In 2013, late-season data are available from LTER Streams sensors starting on August 30th. These discharge values were calculated using a different rating curve from the WERC data.

2014: Discharge was measured several times throughout the summer using a SonTek Flowtracker ADV and wading rod. The stage height was measured at the time of discharge measurement. Continuous stage height readings collected on an hourly basis were then used to calculate continuous discharge using a rating curve for each summer. Temperature was also measured by a HOBO sensor near this location. Discharge was calculated using stage levels measured by the Water and Environment Research Center using a rating curve that they developed.

Temperature and Stage Data in this spreadsheet is from LTER Streams HOBO from this year, except where comments specify. The stage meter from last year washed away from WERC, so that is why stage was used from LTER streams this year.

More information about the methods and raw data can be found at: http://ine.uaf.edu/werc/projects/NorthSlope/upper_kuparuk/uk_river/uk_ri...

Kane, D.L. and Hinzman, L.D., 2014. Climate data from the North Slope Hydrology Research project. University of Alaska Fairbanks, Water and Environmental Research Center. URL: http://ine.uaf.edu/werc/projects/NorthSlope/ Fairbanks, Alaska, variously paged.

2015: Discharge was measured several times throughout the summer using a SonTek Flowtracker ADV and wading rod. High flow measurements were taken by WERC using an ADCP during spring freshet. The stage height was measured at the time of discharge measurement. Continuous stage height readings collected at 10-minute intervals were then used to calculate continuous discharge using a rating curve for each summer. Temperature was also measured by a HOBO sensor near this location. Discharge was calculated using stage levels measured by the Water and Environment Research Center using a rating curve that they developed.

Temperature and Stage Data in this spreadsheet is from LTER Streams HOBO from this year. The WERC stilling well washed away in 2014, so that is why stage was used from LTER streams this year. A new stilling well was installed mid-season in 2015.

The relationships in stage height between the LTER staff gauges deployed in 2013, 2014 and 2015 were used to relate stage recorded from the 2015 stilling well to what stage would have been on the 2013 stilling well. Stages recorded on the 2015 stilling well were calculated as being 0.6ft lower than what stage would have been on the 2013 stilling well.

More information about the methods and raw data can be found at: http://ine.uaf.edu/werc/projects/NorthSlope/upper_kuparuk/uk_river/uk_ri...

Kane, D.L. and Hinzman, L.D., 2014. Climate data from the North Slope Hydrology Research project. University of Alaska Fairbanks, Water and Environmental Research Center. URL: http://ine.uaf.edu/werc/projects/NorthSlope/ Fairbanks, Alaska, variously paged.

2016-2017: Discharge was measured several times throughout the summer using a SonTek Flowtracker ADV and wading rod. High flow measurements were taken by WERC using an ADCP during spring freshet. The stage height was measured at the time of discharge measurement. Continuous stage height readings collected at 10-minute intervals were then used to calculate continuous discharge using a rating curve for each summer. Temperature was also measured by a HOBO sensor near this location. Discharge was calculated using stage levels measured by the Water and Environment Research Center using a rating curve that they developed.

More information about the methods and raw data can be found at: http://ine.uaf.edu/werc/projects/NorthSlope/upper_kuparuk/uk_river/uk_ri...

Kane, D.L. and Hinzman, L.D., 2018. Climate data from the North Slope Hydrology Research project. University of Alaska Fairbanks, Water and Environmental Research Center. URL: http://ine.uaf.edu/werc/projects/NorthSlope/ Fairbanks, Alaska, variously paged.

2018: All data were obtained from LTER sensors and measurements, rather than from WERC. Discharge was measured several times throughout the summer using a SonTek Flowtracker ADV and wading rod. The stage height was measured at the time of discharge measurement. Continuous stage height readings collected at 10-minute intervals were then used to calculate continuous discharge using a rating curve developed each summer. Temperature was also measured by a HOBO pressure transducer at this location.

A large flood starting on September 1, 2018 significantly rearranged the channel cross-section at the discharge monitoring point, with discharge reaching levels well beyond the scope of our rating curve for the season. Therefore, no reliable discharge data are available past September 1.