Sagavanirktok River Spring Breakup Observations 2015 Item Type Technical Report Authors Toniolo, H.; Youcha, E.K.; Gieck, R.E.; Tschetter, T.; Engram, M.; Keech, J. Download date 10/10/2021 14:37:55 Link to Item http://hdl.handle.net/11122/10390 Sagavanirktok River Spring Breakup Observations 2015 Final Report H. Toniolo, E.K. Youcha, R.E. Gieck, T. Tschetter, M. Engram, and J. Keech Prepared for the Alaska Department of Transportation and Public Facilities Water and Environmental Research Center University of Alaska Fairbanks Fairbanks, AK 99775 Report INE/WERC 15.10 December 2015 Sagavanirktok River Spring Breakup Observations 2015 Final Report H. Toniolo, E.K.Youcha, R.E. Gieck, T. Tschetter, M. Engram, and J. Keech Prepared for the Alaska Department of Transportation and Public Facilities Water and Environmental Research Center University of Alaska Fairbanks Fairbanks, AK 99775 Report INE/WERC 15.10 December 2015 The University of Alaska Fairbanks is accredited by the Northwest Commission on Colleges and Universities. UAF is an affirmative action/equal opportunity employer and educational institution. Front cover photo: Aerial view, looking south, of the Dalton Highway (left) and TAPS (right) in the vicinity of Deadhorse, Alaska, on May 22, 2015. Water overtopped the road in several places. Recommended citation: H. Toniolo, E.K.Youcha, R.E. Gieck, T. Tschetter, M. Engram, and J. Keech (2015). Sagavanirktok River Spring Breakup 2015: Final Report. University of Alaska Fairbanks, Water and Environmental Research Center, Report INE/WERC 15.10, Fairbanks, Alaska. For additional information, write to: Publications Water and Environmental Research Center University of Alaska Fairbanks Fairbanks, AK 99775 http://ine.uaf.edu/werc/ ABSTRACT Alaska’s economy is strongly tied to oil production, with most of the petroleum coming from the Prudhoe Bay oil fields. Deadhorse, the furthest north oil town on the Alaska North Slope, provides support to the oil industry. The Dalton Highway is the only road that connects Deadhorse with other cities in Interior Alaska. The road is heavily used to move supplies to and from the oil fields. In late March and early April 2015, the Dalton Highway near Deadhorse was affected by ice and winter overflow from the Sagavanirktok River, which caused the road’s closure two times, for a total of eleven days (four and seven days, respectively). In mid-May, the Sagavanirktok River at several reaches flooded the Dalton from approximately milepost (MP) 394 to 414 (Deadhorse). The magnitude of this event, the first recorded since the road was built in 1976, was such that the Dalton was closed for nearly three weeks. During that time, a water station and several pressure transducers were installed to track water level changes on the river. Discharge measurements were performed, and water samples were collected to estimate suspended sediment concentration. Water levels changed from approximately 1 m near MP414 to around 3 m at the East Bank station, located on the river’s east bank (about MP392). Discharge measurements ranged from nearly 400 to 1560 m3/s, with the maximum measurement roughly coinciding with the peak. Representative sediment sizes (D50) ranged from 10 to 14 microns. Suspended sediment concentrations ranged from a few mg/L (clear water in early flooding stages) to approximately 4500 mg/L. An analysis of cumulative runoff for two contiguous watersheds—the Putuligayuk and Kuparuk—indicates that 2014 was a record-breaking year in both watersheds. Additionally, an unseasonable spell of warm air temperatures was recorded during mid-February to early March. While specific conditions responsible for this unprecedented flood are difficult to pinpoint, runoff and the warm spell certainly contributed to the flood event. i TABLE OF CONTENTS ABSTRACT ..................................................................................................................................... i LIST OF FIGURES ....................................................................................................................... iii LIST OF TABLES .......................................................................................................................... v ACKNOWLEDGMENTS AND DISCLAIMER .......................................................................... vi CONVERSION FACTORS, UNITS, WATER QUALITY UNITS, VERTICAL AND HORIZONTAL DATUM, ABBREVIATIONS, AND SYMBOLS ............................................ vii ABBREVIATIONS, ACRONYMS, AND SYMBOLS ................................................................ ix 1 INTRODUCTION ................................................................................................................... 1 2 STUDY AREA ........................................................................................................................ 5 3 METHODOLOGY AND EQUIPMENT ................................................................................ 9 3.1 Ice Elevations Prior to Breakup (GPS Surveys)............................................................. 10 3.2 X-Band SAR Analysis ................................................................................................... 11 3.3 Water Levels .................................................................................................................. 12 3.4 Acoustic Doppler Current Profiler ................................................................................. 14 3.5 Discharge Measurements ............................................................................................... 15 3.6 Suspended Sediments ..................................................................................................... 17 4 RESULTS .............................................................................................................................. 18 4.1 Air Temperature ............................................................................................................. 18 4.2 Annual Precipitation ....................................................................................................... 20 4.3 Cold Season Precipitation .............................................................................................. 22 4.4 Warm Season Precipitation ............................................................................................ 23 4.5 Surface Water Hydrology............................................................................................... 27 4.5.1 Ice Elevations .......................................................................................................... 28 4.5.2 X-Band SAR Analysis ............................................................................................ 31 4.5.3 Water Levels ........................................................................................................... 37 4.5.4 Discharge Measurements ........................................................................................ 43 4.5.5 Additional Field Observations ................................................................................ 49 4.5.6 Cumulative Volumetric Warm Season Runoff ....................................................... 59 4.5.7 Suspended Sediment ............................................................................................... 63 5 CONCLUSIONS ................................................................................................................... 66 6 REFERENCES ...................................................................................................................... 68 7 APPENDICES ....................................................................................................................... 72 ii LIST OF FIGURES Figure 1. Water level observation network near Franklin Bluffs and Deadhorse. ......................... 3 Figure 2. Study region showing UAF and USGS hydrometeorological stations (green dots), watershed boundaries, and the location of the Dalton Highway (red line). .......................... 6 Figure 3. Hypsometric curve for the Sagavanirktok River basin. ................................................... 7 Figure 4. Locations of spring 2015 breakup flow measurement transects. .................................. 16 Figure 5. Mean monthly air temperature at Franklin Bluffs for the period of record (1986–2015). ................................................................................................................................. 19 Figure 6. Franklin Bluffs mean monthly air temperature from 2014 to 2015 (solid line) is compared with the long-term historical monthly air temperature (squares). ................................ 20 Figure 7. Hourly air temperature at Franklin Bluffs winter 2014–2015. ...................................... 20 Figure 8. Historical rainfall at Franklin Bluffs (n = 26). .............................................................. 24 Figure 9. Imnavait Creek historical rainfall (n = 29). ................................................................... 25 Figure 10. Rainfall at (a) DFM1, South White Hills and (b) DFM3, North White Hills for period of record (2007–2014). ...................................................................................................... 26 Figure 11. Accumulated rainfall at the Atigun Pass Wyoming gauge for the period of record (1983–2014). ...................................................................................................................... 27 Figure 12. Locations of