Experimental work for modular channel – quantifying backwater effects
Loading...
Date
2019-06
Authors
Mas Balqis Binti Mas Lockman Ousin
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Drainage impacts on the environment have given rise to a lot of concern about
the quality and quantity of water. River Engineering and Urban Drainage Research
Centre (REDAC) has implemented the Bio–Ecological Drainage System (BIOECODS)
for ecological swales that have been used around Engineering Campus, Universiti Sains
Malaysia. BIOECODS is designed for both water quantity and quality controls.
Ecological swales are part of subsurface drainage which is environmentally friendly
consist of the grassed swale on top and a conveyance conduit beneath it. REDAC have
carried out many types of researches and developments to improve the application of
BIOECODS. Laboratory tests on a newly – designed REDAC module are carried out to
determine its Manning’s coefficient and to study the behaviour of the flow in the
module through the flow rating curves. The modules were tested under three different
slopes; 1:500, 1:750 and 1:1000 with flow depths varying from 10 – 40 cm while gate
opening consist of 2cm, 4cm, 6cm and gate fully open. The value of Manning’s n
determined for REDAC Module for gate opening 2cm are ranged from 0.044 until
0.223 and for gate opening 4cm are ranged between 0.026 until 0.123. Meanwhile, for
gate opening 6cm the Manning’s coefficient obtained are ranged between 0.018 until
0.041 and for gate fully open are ranged between 0.019 until 0.025. The backwater
effect slowed the flow in modules, energy dissipation was reduced, and storage was
created. The Manning’s n was observed to decrease significantly with increasing of
flow velocity, flow depth, slope and flow rate. This research is important for efficiency
evaluation of a modular channel to act in the subsurface drainage system that consists
of a blockage effect thus to help in solving surface water runoff problems, especially
during peak flow.