WSP07706

• File Number: 8200.765
• Description: White River General
• State: CO
• Basin: Yampa/White
• Water Division: 6
• Date: 1/1/1993
• Author: USGS
• Title: Sediment Transport and Water-Quality Characteristics and Loads - White River - Northwestern Colorado - Water Years 1975 through 1988
• Water Supply Pro - Doc Type: Report/Study

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STREAM DISCHARGE, IN CUBIC FEET PER SECOND (LOG BASE 10)

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Figure 8, The relation of periodic measurements of suspended-sediment loads to stream discharge at site 6,
water years 1983-88.

or storm runoff; (2) receding streamftows during spring
and summer that follow peak runoff conditions; and
(3) base or near constant streamftows during fall and
winter. The regression-data groups for site 6 are shown
in figure 8. Tests for differences at the 0.05 level of sig-
nificance between data groups within each site were
made by using standard analysis-of-covariance tech-
niques. If tests indicated that data groups from the dif-
ferent hydrologic events at a given site were similar, the
data were combined and a single regression was used
for the combined hydrologic events.
The regressions used to estimate instantaneous
suspended-sediment load (Ls) were assumed applica-
ble for computing daily suspended-sediment load (Lsd)
from daily stream discharge (Qd) for the three hydro-
logic events (Porterfield, 1972). Because bias may be
introduced when antilogs are taken of log-transformed
data for regression analysis, a bias correction factor
(Cb), as presented by Ferguson (1986) and discussed by
Elliott and DeFeyter (1986), was applied to each
regression. The bias correction factor for conversion
from common logarithms to the general antilogarithm
form is a function of the regression variance (S2) and is
expressed as:

C (2.65 s2)
b = e '

(3)

where e = 2.71828 and is the base for naturalloga-
rithms.

The general antilogarithm form of the regression
(eq. 2) combined with the bias correction factor (eq. 3)
is:

Ls = lOa Qb Cb'

(4)

By using the assumption that

Ls ~ Lsd, (5)

one to three regressions were developed for each site
to compute daily suspended-sediment loads for the
White River. Regression coefficients used to compute
daily suspended-sediment loads (Lsd) from daily
stream discharge (Qd) at sites 1-4 for water years
1975-88 and sites 5 and 6 for water years 1983-88 are
listed in table 3. The annual suspended-sediment
loads (Lsa) in the White River were measured as the
total of daily suspended-sediment loads (Lsd) for each
water year where LSd values were determined using
the regression equations in table 3,

Instantaneous bedload was measured a total of 7
times at sites 1-4 during snowmelt runoff in June 1988,
and instantaneous bedload was measured 18 times at
site 6 during 1984-86. The bedload samples were
collected simultaneously with samples for suspended
sediment at identical locations in the stream. Instanta-
neous bedload (Lb), in tons per day, is a function of
sampled bedload weight (Wb), in grams; width of the
stream (Ow), in feet; the conversion constant 0.0952;

16 Sediment Traneport and Water-Quality Characteristics and Loads, White River, Northwestern Colorado, Water Veara
1975.88