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Determination of flow resistance coefficient for vegetation in open channel: laboratory study

Ahmad, Noor Aliza and Md Ali, Zarina and Mat Daud, Azra Munirah and Mohd Arish, Nur Aini and Alias, Nur Fatin Amirah (2017) Determination of flow resistance coefficient for vegetation in open channel: laboratory study. In: 4th International Conference on Civil and Environmental Engineering for Sustainability (IConCEES 2017), 4–5 December 2017, Langkawi, Malaysia.


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Abstract. This study focused on determination of flow resistances coefficient for grass in an open channel. Laboratory works were conducted to examine the effects of varying of roughness elements on the flume to determine flow resistance coefficient and also to check the optimum flow resistance with five different value of flow rate, Q. Laboratory study with two type of vegetation which is Cow Grass and Pearl Grass were implement to the bed of a flume. On this matter, Manning’s Equation was used to determine the value of n, which is the roughness coefficient of the channel while Soil Conservation Services (SCS) method was used to determine the roughness contribute by the vegetation. From the experiment were conducted, the flow resistance coefficient for Cow Grassin range 0.0008 - 0.0039 while Pearl Grass value for the flow resistance coefficient are in between 0.0013 - 0.0054. This is depending on the density, arrangement of the vegetation and type of the vegetation used. It was also found that the Manning’s n value is has a directly proportional with the flow discharge. Vegetation with the spacing arrangement recorded increment for Manning’s value at 16.7% are higher compared to vegetation that has closely in arrangement. Pearl Grass (Hemianthusmicranthemoides) recorded the flow resistance coefficient 18.5% higher compared to Cow Grass (Axonopuscompressus). As a conclusion the vegetation roughness value in open channel are depends on density, distribution type of vegetation used and physical characteristic of the vegetation itself

Item Type: Conference or Workshop Item (Paper)
Subjects: T Technology > TD Environmental technology. Sanitary engineering > TD201-500 Water supply for domestic and industrial purposes
Divisions: Faculty of Civil and Environmental Engineering > Department of Water and Environmental Engineering
Depositing User: Mr. Mohammad Shaifulrip Ithnin
Date Deposited: 23 Jun 2019 06:55
Last Modified: 23 Jun 2019 06:55
URI: http://eprints.uthm.edu.my/id/eprint/11630
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