KONSENTRASI SEDIMEN SUSPENSI RATA-RATA KEDALAMAN BERDASARKAN PENGUKURAN 1, 2, DAN 3 TITIK PADA ALIRAN SERAGAM SALURAN TERBUKA
ABSTRACT: The most
appropriate and précise
method for determining suspended
sediment concentration or
suspended sediment discharge
in channels is by
sampling of suspended
sediment data directly
from the channel. Depth-integrated and points-integrated-sampling are
the methods that generally used
to obtain depth-averaged suspended
sediment concentration. Points-integrated-sampling method is
considered to be
more accurate compared with depth-integrated-sampling.
However, points-integrated-sampling method needs the profile of suspended sediment concentration at the overall
depth, which means that the
method needs much more times
and cost to collect
data sampling. The
points-integrated-sampling method will be more useful, if the data sampling can
be collected only at certain points. Whether or not the data of suspended
sediment concentration taken at certain points – i.e., at one, two, or three
points – is sufficient to determine the
depth-averaged suspended sediment
concentration, it will be
analyzed in this
report, based on laboratory and
field data. One hundred and twenty-five (125) profiles of suspended sediment
concentration of laboratory data − measured in flume at 5 different positions
in transversal direction, from the center to the edge of channel −, and fifty
(50) profiles of field data − measured in Mataram irrigation channel at 5 different
positions − are analyzed. For each profiles,
the depth-averaged of
suspended sediment concentrations are
calculated and compared
with the ones obtained from one, two, or three points
of measurements. The results of the analyzed data show that the depth-averaged suspended
sediment concentration, yC , can be determined from one, two, or three points
of measurements, i.e., at y = 0.4 D for one-point of measurement, at y = 0.2 D
and 0.8 D for two-points of measurements, and at y = 0.2 D, 0.4 D, and 0.8 D for
three-points of measurements, according
to the Equations 9, 10,
and 11 of
this report. In the
range of the analyzed data, the equations are valid
both for laboratory and field data, and for the data collected from the center
to the edge of the channel.
Keywords: depth-averaged
suspended sediment concentration, one-two-three points
of measurements, transversal direction
Penulis: Bambang Agus Kironoto
