Authors

Abstract

In this research, an attempt has been made to have full understanding about the
nature of the sediment in the flow. Due to the difficulties during flood periods, the
attention was focused on the shortcut methods to measure the average sediment
concentration in the water column. These methods use limited number of water
samples. Two groups of data have been utilized. The first group covers the field work
in Tigris River at Sarai site and middle Euphrates canals. The second group is outside
Iraq which covers Missouri River in Montana. The data of the first group has been
used for analysis of Imara’s semi-empirical equation for the measurement of the
average concentration in the water column. In this equation, an empirical constant,
(a) , was given a value of (10) in estimating the sediment load in the tributaries of
Adhaim River. A uniformity index was suggested, to analysis the vertical distribution
of different kinds of sediment, and then uniformity index for different kinds of
sediment was calculated for Missouri river in the second group of data. The value of
the empirical constant, (a) varied between (7.2) and (11.65) with an average value of
(9.4) for group one data compared with the value of (10) used for the tributaries of
Adhaim River. This value was accepted with a significance level (α = 0.05). The
uniformity index gave a value close to (1.0) for clay and silt, and a value between (1.5)
and (2.5) for sand depending on the sand’s grain size.