Impak saliran terhadap alam sekitar telah menimbulkan kebimbangan mengenai kualiti dan kuantiti air. Pusat Penyelidikan Kejuruteraan Sungai dan Saliran Bandar (REDAC) telah melaksanakan Sistem Saliran Bio – Ekologikal (BIOECODS) untuk swales ekologi yang telah digunakan di sekitar Kampus Kejuruteraan, Universiti Sains Malaysia. BIOECODS direka untuk kawalan kuantiti dan kualiti air. Swales ekologi adalah sebahagian daripada saliran bawah tanah yang terdiri daripada lapisan parit berumput di atas dan saluran air di bawahnya. REDAC telah menjalankan pelbagai penyelidikan dan perkembangan untuk penambahbaikan penggunaan BIOECODS. Ujian makmal pada modul REDAC telah dilakukan untuk menentukan pekali Manning n dan mengkaji corak aliran dalam modul berdasarkan graf kadar aliran. REDAC modul telah diuji di bawah tiga kecerunan yang berbeza; 1: 500, 1: 750 dan 1: 1000 dengan kedalaman aliran bervariasi dari 10 - 40 cm manakala pembukaan pintu terdiri daripada 2cm, 4cm, 6cm dan pintu terbuka sepenuhnya. Nilai Manning n diperoleh untuk Modul REDAC pada pembukaan pintu 2cm berkisar dari 0.044 hingga 0.223 manakala pintu pembukaan 4cm berkisar antara 0.026 hingga 0.123. Bagi pembukaan pintu 6cm, pekali Manning diperoleh adalah antara 0.018 hingga 0.041 dan untuk pintu terbuka sepenuhnya berkisar antara 0.019 hingga 0.025. Kesan balik air melambatkan aliran di dalam modul, mengurangkan pelesapan tenaga, dan menghasilkan simpanan setempat. Manning n diperhatikan berkurangan dengan peningkatan halaju aliran, kedalaman aliran, cerun dan kadar aliran. Kajian ini diharap dapat menyumbang kepada penambahbaikan sistem saliran mesra alam terutamanya dalam menyelesaikan masalah air larian permukaan semasa aliran puncak. Penyelidikan ini penting untuk menilai kecekapan saluran modular dalam menghadapi kesan penghadangan yang seterusnya akan membantu menyelesaikan masalah aliran air permukaan semasa aliran puncak.
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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.
Experimental work for modular channel – quantifying backwater effects / Mas Balqis Mas Lockman Ousin