Streambed vertical hydraulic conductivity (Kν) plays an important role in understanding and quantifying the stream-aquifer interactions. While several researchers have discussed the spatial variability of streambed horizontal hydraulic conductivity or Kν at one or several close-located sites in a river, they did not develop any statistical distribution analysis of streambed Kν at distant sites along a large river. In this paper, the statistical distribution and spatial variation of streambed Kν at 18 test sites in a 300-km reach of the Platte River in Nebraska are presented. In-situ permeameter tests using the falling-head method were carried out to calculate the streambed Kν values. Fine-grained sediments transported by two tributaries, the Loup River and the Elkhorn River, to the Platte River appear to result in lower streambed Kν values downstream of the confluences between the Platte River and the tributaries. The streambed Kν values were found to be normally distributed at nearly each test site. When the correlated Kν values were eliminated from the grid sampling plots, the remaining independent sub-datasets of streambed Kν values were still in normal distribution at each test site. Furthermore, the combined streambed Kν values upstream of the first confluence between the Platte River and the Loup River was normally distributed, which may be due to the lack of tributaries in-between and thus streambed sediments were well distributed in this reach and belonged to a single population of hydraulic conductivity values. In contrast, the combined dataset of all measurements conducted downstream of this confluence was no longer in normal distribution, presumably as a result of the mixing of different sediment sources.
- Normal distribution
- Permeameter test
- Platte River
- Streambed vertical hydraulic conductivity
ASJC Scopus subject areas
- Civil and Structural Engineering
- Water Science and Technology