With the rapid development worldwide, including in Malaysia, urban modernization has significantly altered natural environments. River channelization, in particular, has disrupted the natural meandering patterns, leading to structural and functional changes within the river ecosystem. This alteration poses a threat to biodiversity and can result in the degradation of freshwater ecosystems. To address these challenges, the implementation of artificial riffle structures emerges as a viable solution. These structures mimic the natural pool-riffle sequence by utilizing two types of concrete with varying heights, aiding in the restoration of river morphology, water quality, and aquatic habitats.
This paper focuses on studying the flow characteristics within the artificial riffle zone through numerical modeling. Numerical modeling serves as a practical tool for comprehending flow dynamics in such environments. Utilizing the Flow-3D model, a widely recognized commercial software, flow simulations are conducted across five different sets of flow Froude numbers to assess turbulent kinetic energy within the artificial riffle zone. The results of the numerical simulations reveal distinct variations in turbulent kinetic energy concerning flow depth and position within the artificial riffle zone. These findings have implications for sediment transport processes both within the artificial riffle zone and its upstream and downstream areas.
Furthermore, the strategic placement of artificial riffle structures has the potential to enhance oxygen levels within the river, thereby contributing to ecological restoration efforts to a certain extent. By examining the flow dynamics and turbulent characteristics within artificial riffle zones, this study provides valuable insights into optimizing the design and placement of such structures for effective river ecosystem management and restoration.