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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />! <br /> <br /> - <br /> 4 <br /> I <br />18V7 I <br />The results of the HEC-2 hydraulic models were imported into SAM and used to describe I <br />a set of hydraulic parameters for sediment transport cilIculations. This was accomplished by <br />specifying a portion of each sub-reach as representative of the hydraulic conditions and <br />calculating average vilIues for velocity, depth, width, and energy slope for each discharge value. I <br />These parameters were then used, ilIong with bed material particle distribution information, to <br />generate sediment transport rating curves for the sub-reaches. The "Bent's Fort" particle <br />distribution from the geomorphological assessment completed in 1997, discussed in 3.1 I <br />GEOMORPOLOOICAL ASSESSMENT, waB used for the bed materiiII parameters. This <br />particle distribution closely matched the "Highway 207" distribution, located 30 miles upstream, <br />from the same report suggesting uniform bed materiiII throughout the reach. The Brownlie I <br />sediment transport equation was used to cilIculate transport. This equation was used because the <br />Stable Channel geometries are calculated with this equation, thus preserving theoretical <br />consistency. The Brownlie sediment transport equation would not necessarily be the fIrst choice I <br />for transport calculation, but it is applicable to sand-bed rivers such as the Lower Arkansas. <br />Three groups of conditions were analyzed. The reach-averages from each problem area I <br />were used to indicate current conditions. BecaUSe of the length of Problem Area I, it was broken <br />into 4 parts. The sediment transport rates for this condition are listed in Table 3.5. The second <br />condition analyzed used only the HEC-2 cross-sections with a capacity of at least 1,000 cfs. The I <br />results are shown in Table 3.6. <br />Table 3,5. Existim sediment transoort rates (reach averal1.ed hvdraulic parameters). I <br />Discharge Problem Problem Frob. Area Frob. Area Frob. Area Prob. Area <br /> Area 3 Area 2 I, Dart 1 I, Dart 2 1, Dart 3 I: part 4 <br />(cfs). (tld) (tld) (t1d) (tld) (tld) (tld) I <br />100 2.35 1.38 0.41 4.53 2.52 4.81 <br />200 16.66 13.23 7.25 26.58 17.20 29.14 <br />300 43.93 37.93 23.69 64.30 43.05 71.59 I <br />500 131.32 119.00 79.57 163.13 113.52 206.64 <br />750 293.11 264.82 184.90 321.62 229.28 433,28 <br />l,ODO 510.75 445.83 327.46 500.01 394.78 720.64 I <br />Table 3.6. In-channel sediment transDort rates at least 1,000 cfs capacitv). I <br />Discharge Problem Problem Frob. Area Frob. Area Frob. Area Prob. Area <br /> Area 3 Area 2 1, Dart 1 1, part 2 1, part 3 1, Dart 4 <br />(cfs) (tld) (tld) (tld) (tld) (tld) (tld) I <br />100 4.31 10.91 5.13 9.24 44.37 15.16 <br />200 27.91 57.73 20.81. 48.26 166.04 69.38 <br />300 74.07 137.22 45.95 113.61 356.00 156.09 I <br />500 232.66 360.24 128.99 315.07 960.48 . 400.71 <br />750 557.81 746.22 331.43 694.00 1,628.24 818.97 <br />1,000 1,028.76 1,218.29 603.32 1,481.66 3,611.55 1,406.84 I <br /> I <br /> - <br /> 32 I <br /> <br />\ <br />