Laserfiche WebLink
<br />The tape then was moved and measurements were repeated until a grid was <br />completed that spanned the entire stream for a distance of usually 15 feet. <br />The grid normally started 3 feet downstream of the measurement section and <br />extended 12 feet upstream of the measurement section. The particle of bed <br />material below each grid point was sampled by recording the short, inter- <br />mediate, and long diameters, by recording which of these diameters were <br />oriented vertically and horizontally, and also by estimating Krumbein round- <br />ness (Krumbein, 1941). Bed material was returned as close as possible to its <br />original location and position in the stream. Bed material at a typical sta- <br />tion is shown in figure 5. When significant amounts of fine material were <br />found, bulk samples of the fine material near the surface of the bed were <br />obtained, and a standard sieve analysis was conducted (Benson and Dalrymple, <br />1967). Bulk samples were obtained at the Cache La Poudre River and South <br />Platte River sites. No measures of bed form were made at either site because <br />of the high-flow conditions. Boils were noted during all three measurements <br />at the South Platte River site and are indicative of dune bed forms (Simons <br />and Senturk, 1976). <br /> <br /> <br />Figure 5.--Upstream view of rough bed material, Bear Creek <br />at Morrison, October 18, 1983. <br /> <br />10 <br />