Nebraska Academy of Sciences
Date of this Version
1991
Abstract
The United States Army Corps of Engineers, U.S. Geological Survey, and Nebraska Game and Parks Commission cooperated in 1989 to obtain physical data from cross-section transects along the unchannelized Missouri River in northeastern Nebraska. Bed-sediment samples were collected from locations along these transects and taken to the laboratory. Mean particle-size and standard deviation were determined by weighing material retained on seven U.S. Standard sieves after being on a sieve shaker for six minutes. Organic matter content of each sample was obtained by ashing an aliquot in a muffle furnace to remove the organic portion. A new system for coding sediment mixtures was developed, and coded sediment and organic matter content were compared with depth and velocity in a regression analysis. The most common mean particle-size was determined to be medium sand; however, some samples were as coarse as fine gravel. Organic-matter content was less then 3% for the most part; however, it was measured as high as 20%. Sediment and organic matter were related to depth and velocity; however, r-square values were low, suggesting that other factors contribute to the observed variability in the sediment mixtures and organic matter content.
Comments
1991. Transactions of the Nebraska Academy of Sciences, XVIII: 11-17. Copyright © 1991 Hesse and Mestl.