WSP01928

• File Number: 8272.500
• Description: Colorado River Basin Salinity Control - Colo Dept of Public Health - WQCC and WQCD
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1970
• Author: Lynn Shown
• Title: Evaluation of a Method for Estimating Sediment Yield
• Water Supply Pro - Doc Type: Report/Study

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correspond, then the rating should be adjusted and the
adjusted rating could then be used (IS ,~ guide when
applying the method in areas similar to the gaged one.
If " team of classifiers arc going to survey an area. it
'would be well that all members agree on their inter.
p['Ct<'~tion of the characteristics used to rate the factors.
This should pre"ent wide differences between sediment.
yield estimates made by two or more classifiers who
ra te similar arens.
The regression coefficients (slopes of the dashed lines
in fig. 2) are not significantl.v different for Xew )Iexlco
and .Wyoming watersheds, but the coefficient for the
Badger Wash watersheds is significantly different from
the other two at both the 1- and j-percent le,'els. The
most Iikel~' reason for the different slope for the Badger
'Vash relation is the magnitude of thc point near the
upper end of the line in figure :2.4. The estimated sedi.
ment yield represented b~' that point is more than 1.
acre. foot per square mile larger than the measured
sediment yield, nnd this causes the upper end of the
line to be lower.
Scatter about the regression line is greatest for the
Wyoming sites (fig. 2C). It is the 'llithor's belief that
much of the scatter is due to the dillkulty in el'aluating
the sediment-transport factor. Ther~ arc acti,'e flood
, plains, particularly in the lower reaches of many of thc
'\')'oming \~ntershcds cxamincd. It is apparent that
S<!diment is being trapped by the grass co"er on the
flood plains, but it was difficult to judge hOlY much
sediment was retained and how Illuch mo"ed OJ! to thc
rcsen'oirs. This difliculty partly accouuts for the csti,
mated sediment yields being g~ater than measured
S<!diment ~'ield for about half of the poims in figure 2C.
The two poiuts at tbe lowet. right in figure 2(' are
for rescr\'oirs that were kno\\'l1 to spill large nmounts
of wilter, and the recorded sediml'nt,yield figures for
them are probably too low. For the two watersheds rep-
rcscntedby the upper two points 011 the left side of

.,

SHOWN

B249

fi:n'1'(' 2('. it appeared that the present.day sediment
yichl was ll1uch less than tbat, sho\~n by the reservoir
I'cent.c!s. which wcre obtained prior to 1950. These
watersheds arc probably grazed less intensi,'ely 1I0W,
resulting in lo\~er sediment yields than during the
period of record.

REFERENCES

Burkham. D. E., 1006. Hrdrology of CornacId Wash area. and
~tf'~ts of Jnnd-tr(>n.tment L>racticps. Sandor41 Countr.
X. )lex.. 1ro1...oo: t'.S. Geol. Surrey \\'ater,Sl1pplr Paper
1831. 51' I'. [1001'J,
. tuller. R. C.. 1001. Hydrology of litock.w:tter reser,'o(r:i in Cp-
per ChE'rE'nn~ River uasin: FS. Geot. Sun-ey 'YntE>f-Supply
Paller 1.j,'l1-A. 136 p,
Enlils. R. A.. nud Lo\'E". R. :\1.. 103f, The stell poh'lt method of
S:lwpJing-a practical tool in range research: Jour. Ra.cge
).rn.n.Qg~ment. y, 10. }\. ~S-212.
H:1dley, n. F.. :'Iud Schumm. S. .\... 1001. ::iediUleut' sourC'€-s aUt\
drainnge-lJasiu. ~ha.ractet'istics in upper Cheyenne Ri'\"e:r
basin: r~.s. Ge-ot. Sune)' W'nter-Supply Paper 1531-B.
108 p.
Kin;. X.J.. lO,jO. Hydrologic data. Wled Ri,'er aDd Fifteen
:'I1i1e Creek basins. "-.roming. 1{}.,l';"-;H: CS. GeoL Snn-e.,",
"Yater-Supply Pnpe'r 14i~_\. +-l p.
Lusoy, G. C., Turner. G. ToO Thompson, J. R.. and Reid,' '-. H.,
1063. HnIrologle <1n<1 lriotic characteristics o( g>r<1zect and
tingrnze<l w:ltersheds Dt 'tile Badger Wrtsll lH1:sil1 i'n 'Testern
Colorndo. l!)~;jS:. 1'.:$. Geo1. SUrrer Water-S.upplr 'Prtper
1532-B. 1'3 p.
Pacific Soutlnl"est rllter-~\!;ellcy Committet'o 100~. Report all
(actors affecting ~edjJUpnt yield iu tlJe Pacific $Ql1tltwes:t
are:.l: Wattor )1.lJl:.J;::'t'ment i:'lIi1('ommitte-t>. ~e<linI(>-nr'ntioll
T~sk Force. 10 p.. ~ t<lules.
l'Nerson, H. ".. l~. HydroloIT ot ~mrtll watersheds ill '".esr~
ern States: {-.S. Ge-ol. ~ul";ey U'nter.Supply Pnper 147,j..-I,
p. 217-356.' .
r,s;. DEopartmE'1lt 1)( Comroerc(>., l~. .Climatological' <lnto.-:...
.\:nou31 .sUWOlury tor' "-rolDing: ,'. j7, no. 13. ,
r:.s. ".ellt~er D~re:1u. 100i'. Xormnf annual precipit:llioH and
normal- :\!ar-8E'pteuiber precipit:ni~n [Xe\\' .llexico]: Iso-
hsetolm:1p pretHlre<l hy Ihe Water-Supply Forecast ('enter..
W~stern. Region. ~nlt' f.nke CitY'. t"bh. for En'YirohmNlt:ll
Sci. Sen'. Adn>.

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