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where: <br />L = monthly mean transport rate, in tons per day; <br />b = 0.0027, a conversion factor to convert milligrams per <br />liter X cubic feet per second to tons per day; <br />d = days per month; <br />j = days of month; <br />Cj = daily concentration, in milligrams per liter; and <br />QJ . = daily discharge, in cubic feet per second. <br />Because of the large number of calculations involved, equations 4 <br />and 6 were incorporated into a computer program developed by Glover <br />(1978). The basic procedure is illustrated in figure 18. Daily loads <br />are calculated, and monthly loads are then determined by summing the <br />daily values. Monthly mean suspended-sediment transport rates for six <br />sites in the study area are shown in figures 19-24. <br />Radlnad <br />Bedload was sampled at five locations in the Big Sandy River basin <br />with Helley-Smith bedload samplers (fig. 25), using a technique developed <br />by Emmett (1979). Samples were collected at 20 or more vertical sections <br />at each site to determine the average bedload and particle-size distribu- <br />tion in the cross section (table 7). <br />Although the Helley-Smith bedload sampler is used widely by the U.S. <br />Geological Survey, other Federal and State agencies, and university and <br />private organizations, it has not been officially sanctioned by the <br />Federal Inter-Agency Sedimentation Committee (Water Resources Council) <br />nor certified for its technical performance by the U.S. Geological Sur- <br />vey. This certification is awaiting completion of rigorous laboratory <br />testing of the sediment-trapping characteristics of the sampler under <br />direction of the U.S. Geological Survey and the Federal Inter-Agency <br />Sedimentation Committee. Laboratory testing of the sampler probably will <br />not be completed until the mid-1980's. <br />The average channel-wide transport rates in table 7 were determined <br />from a cross-sectional series of measurements and multiplied by the <br />cross-sectional width to obtain the total bedload transport rate. The <br />few measurements available show that the total bedload transport rate is <br />directly proportional to water discharge. At most of the stations the <br />total bedload transport rate increases at a faster rate with increasing <br />discharge than does the suspended-sediment transport rate. <br />27