Utilizing of shields factors for sedimentation movements and drainage channels at the middle of Iraq (as a case study)

Abstract

The shields factor seems to be a non-dimensional quantity which is utilized to determine the commencement of sediments movement in channels. This study intends to analyze sediments movement in channels of drainage and irrigation in Iraq by utilizing these characteristics as a determinant, and to establish a suitable formula to describe this impact in estimating sediments discharge. Based on seasonal unpredictability of the data, the field and laboratory work was completed across a 36-month period from January 2015 to January 2018. The soil texture was silty sand with a little clay amount, and the specific gravity magnitudes of the soil specimens vary from 2.66-2.73. Furthermore, the Shields factor magnitudes (θ) for movement were greater comparison with the critical magnitudes (θcr) in all channels; sediments transmission has been situated along the channels, according to the research. Using the Shields factor, two logarithmic formulas have been devised to quantify sediments discharge. The Flowing in irrigation channels has a correlation magnitude of 0.9007, whereas the Flowing in drainage channels has a correlation coefficient of 0.644. This demonstrated that the shields factor and sediments transport in irrigation channels had a significant degree of association. The drainage channels, on the other hand, have a significantly lower degree of correlation. This reflects the requirement to design a routine maintenance schedule for certain channels and to ensure that hydraulic Flowing criteria are met.