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<br />~ <br />... <br /> <br />Table 5. Estimates of sediment contrlbullon by streamflow from 219 ungaged tributaries of the Colorado River between Lee's Ferry and the <br />Grand Canyon gage (river mile 87), Arizona. <br /> Area Q., Q., Sediment yield <br />Source Original equation Units (km') (10a Mg/yr) (Mg yr-' km,2) <br />tFlaxman (1972) log (Y + 100) = 6.21301 - 2.19113 log (X, + 100) + ac-ftlmi2/yr 3,282 na 0.t4 42.6 <br /> 0.0603410g (X2 + 100) - 0.01644 log (XJ + 100) + <br /> 0.04250 log (X. + 100) <br />Renard (1972) 0.001846 A -0.1187 ac~ftIac/yr 3.282 0.67 0.44 204 <br />Soil Conservation Service (1975) PSIAC method ac-ftlmi2/yr 3,282 nd 13.5 4,110 <br />Strand (1975) 1130Ao.77 mJ/yr 3.282 1.62 0.69 494 <br />'Dendy and Bolton (1976) 1280 Q 0.'6 (1.43 - 0.26 log A) tonslmi2/yr 3,282 0.81 0.39 247 <br />"Howard and Dolan (1981) 780 A Mgikm2/yr 3,282 2.56 2.56 780 <br />"Randle and Pembenon (1987) 1750 A -0.2' m3fkm2/yr 3.282 2.4 2.7" 731 <br />Graf(1987) 1200A 1.0 m3fyr 3,282 3.9 3.9 1,190 <br />"Andrews (1991) gaging data (1941-1957) tonslyr 3,748 na 8 2.130 <br /> <br />~ <br />~ <br />a <br />~ <br />< <br />CD <br />< <br />.,. <br />'< <br />c: <br />::I <br />CD <br />.. <br />'lil <br />0- <br />~ <br />i7 <br />c:: <br />~ <br />.. <br />.. <br />!l. <br />S' <br />CD <br />~ <br />0' <br />;1 <br />0- <br />o <br />:D <br />< <br />!!l <br />:;- <br />Gl <br />~ <br />IS <br />::I <br />0- <br />n <br />.. <br />::I <br />'< <br />o <br />::I <br /> <br />.A = drainage area in the units given; Q-II = sum of sediment yields calculated for each individual tributary (used for sediment yield); Q.tl = sediment yield calculated for entire drainage <br />area of 3,282 km2 (Melis et aL, 1994). Sediment density is estimated 851,200 kg/m3. <br />l' Y = sediment yield in ac_ftlmi2/yr; XI = mean annual precipitation (inches) I mean annual temperature (OF), estimated as 0.19; Xz = watershed slope, eslimaled as perc~nl gradienl of main <br />channel~ X) = percent of particles > I mm in diameter in the firsl 2 inches of soil, estimated as 60%~ X4 = soil pH factor. assumed to be 0 (pH of7). <br />~ Q = annual runoff in inches assumed 10 be 0.4501 A -0.1449 (A in mi2). <br /># Derived from daily suspended sediment loads. <br />.. Sum of calculations by Randle and Pemberton (1987) for ungaged drainage area from Lees Ferry to the Liule Colorado River (A == 3,095 km2) and from the Little Colorado River 10 <br />Grand Canyon (A == 4-66 'mho <br />na, nOl applicable with given equation/method <br />nd, no dala available <br />