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<br />~ <br />... ~ ,,'.,.. <br /> <br />The roughness measured reflects primarily the bed and bank material <br /> <br />roughness and represents average total main channel flow resistance. <br /> <br />The discharges at these sites ranged from low flows to high flows <br /> <br />equivalent to peak flo\~s, and recurrence intervals ranged up to about 25 <br /> <br />years. All flows were within the main channel. <br /> <br />The fol lowing description of field methods is brief because stan- <br /> <br />dard U.S. Geological Survey procedures were used to measure streamflow <br /> <br />(Benson and Dalrymple, 1967; Dalrymple and Benson, 1967; and Buchanan <br />and Somers, 1969), and the well-known methods of Wolman (1954) were used <br /> <br />to measure particle size. At each site, three to five cross sections <br /> <br />" <br /> <br />/,r <br /> <br /> <br />were established and marked with metal stakes to define the reach of the <br /> <br />stream. The cross sections were spaced approximately one channel width <br /> <br />apart. When a current-meter measurement of discharge was made, concur- <br /> <br />rent water-surface elevations were measured from about one channel width <br /> <br />upstream to one channel width downstream of the site on each bank, <br /> <br />including at the ends of each cross section to define the water surface <br /> <br />profile. Because extreme turbulence in the stream caused waves, the <br /> <br />average maximum wave \~ashup was taken to be the water'"lSurface elevation. <br /> <br />The conditions related to flow in each reach, such as the water-surface <br /> <br />characteristics, lack of bed-material movement, and amount of wave <br /> <br />washup, were recorded and photographed. <br /> <br />~ <br /> <br />. ,f <br />~~ A' <br />-"'-7 <br />..0 <br />I' ' <br /> <br />/1 <br />