Using of shields parameter as a determinate for the sediment movement in irrigation and drainage channels : a case study in central region of Iraq

الملخص EN

Shields parameter is an important non dimensional number used to calculate initiation of moving of sediment in channels.

This research aims to evaluate sediment movement by using this parameters as a determinant , and to find the appropriate equation to explain this effect in calculating of sediment discharge in irrigation and drainage channels in Iraq.

The field and the laboratory works have been achieved within a period of 12 months from March 2015 to March 2016 due to cover the seasonal variability of the data.

The results shows that the soil texture is silty sand with a small rate of clay and specific gravity value of soil samples ranged between 2.66-2.73.

Moreover, the study found that the Shields parameter values (θ) for the movement are larger than the critical values (θcr) in all channels, also; the transmission of sediment is located along the channels.

Two logarithmic equations have been developed to estimate discharge of sediment by using the Shields parameter.

The correlation coefficients is 0.93 for the flow in irrigation channels and 0.61 in drainage channel .

This indicated that there is a high correlation level between shields parameter and the movement of sediment in irrigation channels.

While there is a slightly low level of correlation in the drainage channels.

This mirrors the need to develop a periodic program for maintenance of those channels and to maintain hydraulic flow specifications.