Estimation of average suspended sediment concentration in a flow depth by one sample

الملخص EN

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 for group one data compared with the value of (10) used for the tributaries of(9.4) 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.