IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
Log On
About IAHRDirectoryCommitteesMy IAHRNews & JournalseLibraryeShopEventsJoin IAHRWorld CongressDonate
spacer.gif
spacer.gif eLibrary
spacer.gif eLibrary
You are here : eLibrary : IAHR World Congress Proceedings : 36th Congress - The Hague (2015) FULL PAPERS : THEME 3- SEDIMENT MANAGEMENT AND MORPHODYNAMICS : COMPARATIVE STUDY OF ORIGINAL ACKERS & WHITE RELATION ALONG WITH MODIFIED COEFFICIENT FOR TOTAL SEDI...
COMPARATIVE STUDY OF ORIGINAL ACKERS & WHITE RELATION ALONG WITH MODIFIED COEFFICIENT FOR TOTAL SEDIMENT LOAD PREDICTION
Author : S. I. WAIKHOM1, DR. S. M. YADAV2
Reliable and quantitative estimates of sediment transport are very important in river engineering and water management projects. Numerous comparison studies, by researchers like Nakato T, Wu et al. and others, have been conducted on sediment transport using various total load formulas for wide range of flume and field data. Most of these studies conclude that Ackers & White relation is quite reliable and a good predictor. In light of this outcome, an analysis was done using this relation for the flume data set of Samaga et al, Soni J P and river data of Tofalleti F.B , with an aim to verify the validity of result for Indian terrain envisaging further test and applicability of the Ackers & White relation. Comparison was also done with Ackers & White relation incorporating modified coefficient. The performance of the selected sediment formula was tested on the basis of accuracy in predicting the observed sediment within a certain discrepancy ratio. Statistical analysis and graphical comparison are utilized to demonstrate the performance and variations for different data sets. Overall, original Acker & White function under predicts, with percentage error ranging from -20% to -90 %, for all the selected data sets. The evaluation revealed that, for all four mixtures (of Samaga et al data set), prediction of sediment load is superior in comparison to other data sets. It was also observed that both Acker & White (1973) and Acker & White (1990) function gives better value for d as representative size of the bed material 35 instead of d in Samaga et.al data set. It was also noted that the result predicted by both selected transport function has 50 little difference for d ranging from 0.24 mm to 0.35 mm in almost all chosen data sets. Analysis of the result also 50 conclude that Ackers and White (1973) function changes its trend from under prediction to over prediction as the diameter decreases but interestingly, predictions with the modified parameters (Ackers and White,1990) deviate significantly from that of the original formula, except for a very few cases for sediment diameter less than 0.18 mm as unpredictable trend is observed in Ackers and White (1990) approach. When the diameter decreases it over predicts but again in some cases it under predicts to high degree of deviation so diameter of sediment alone cannot judge the trend of prediction which was observed in the prediction of transport rate using Tofalleti .F.B.data set.
File Size : 1,739,377 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 36th Congress - The Hague (2015) FULL PAPERS
Article : THEME 3- SEDIMENT MANAGEMENT AND MORPHODYNAMICS
Date Published : 18/04/2016
Download Now