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STREAMBED HYDRAULIC CONDUCTIVITY FOR RIVERS IN SOUTH‐CENTRAL NEBRASKA 1
Author(s) -
Chen Xunhong
Publication year - 2004
Publication title -
jawra journal of the american water resources association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.957
H-Index - 105
eISSN - 1752-1688
pISSN - 1093-474X
DOI - 10.1111/j.1752-1688.2004.tb04443.x
Subject(s) - permeameter , silt , hydraulic conductivity , hydrology (agriculture) , geology , aquifer , alluvium , sediment , streams , soil science , geomorphology , soil water , geotechnical engineering , groundwater , computer network , computer science
This paper presents hydraulic conductivities of streambeds measured in three rivers in south‐central Nebraska: the Platte, Republican, and Little Blue Rivers. Unlike traditional permeameter tests in streams that determine only the vertical hydraulic conductivity (K v ), the extended permeameter methods used in this study can measure K in both vertical and horizontal as well as oblique directions. As a result, the anisotropy of channel sediments can be determined from streambed tests of similar sediment volumes. Sandy streambeds with occasional silt/clay layers exist in the Republican and Platte Rivers. The average K v values range from about 15 to 47 m/day for the sandy streambed and about 1.6 m/day for the silt/clay layers. Statistical analyses indicated that the K v values of sand and gravel in the Platte and Republican Rivers essentially have the same mean; but the K v values from the Little Blue River have a statistically different mean. K v is about four times smaller than the horizontal hydraulic conductivity (K h ) for the top 40 cm of sandy streambed. Measured K h values of the sandy streambed are in the same magnitude as the K h of the alluvial aquifer determined using pumping tests. The smaller K v value in the whole aquifer is the result of interbedded layers of silt and clay within the sand and gravel sediments.