The objective of this research was to investigate the relationships between lateral inflows and watershed characteristics within the Kuparuk Watershed of Arctic Alaska, as well as to quantify the lateral inflows to be used as an input and in the calibration of a process based instream temperature model.
Determination of lateral inflows was accomplished by constructing hydrographs at various locations along Imnavait Creek and the Kuparuk River using stage and discharge measurements made in the field. The hydrographs were then routed downstream (starting upstream) using the Muskingum method; and thus subtracting the routed hydrograph from the downstream measured hydrograph to calculate any additional water that had entered the reach between hydrologic stations.
Results showed, as a general trend, reaches within the northern foothills of the Brooks Range experienced larger lateral inflow contributions per square kilometer and had larger runoff ratios than subsequent reaches to the north where the terrain flattens out and transitions into the coastal plain. Two reaches within the watershed contradicted the general trend. The low‐gradient reach nearest to the Arctic Ocean experienced larger lateral inflows throughout the summer that were unaffected by precipitation events, this is believed to be caused by snow melt initially stored in the low gradient topography and later released. This area is rich with wetlands, ponds, and lakes and snow‐damming during breakup is prevalent. The other reach was located upstream of the Kuparuk aufeis field and was observed to lose water during the summer of 2013, supporting a hypothesis that the aufeis is fed throughout the winter by a lage talik above the aufeis formation.