The balance of environmental flow in basin-maintained ecosystems is crucial for sustaining biodiversity and the environment. Maintaining optimal environmental flow in rivers ensures the sustainability of natural ecosystems. An Environmental Flow Assessment (EFA) was conducted in the Terengganu River (outlet) and Petuang River (inlet) to assess whether river flow is sufficient to support ecological and biodiversity needs. The study aimed to develop a hydrological-hydrodynamic model to determine Environmental Flow Values (E-Flow) and to use ecohydrological indicators for restoration and rehabilitation in the Kenyir Lake basin. Sampling was carried out during both the dry and normal seasons. Data were collected on hydrology (water level and river discharge), hydrodynamics (using XPSWMM software), and ecology (fish sampling and Length-Weight Relationship (LWR)). Three sampling stations were selected on each river, with the fish species Toman (Channa micropeltes), Sebarau (Hampala macrolepidota), and Belida (Chitala lopis) chosen as bioindicators. These species were selected based on their size (width, length, and weight), which indicates their tolerance to Environmental Flow Values. A 7Q20 low-flow analysis revealed that in the Terengganu River, the optimum discharge was 42.78 m³/s, with a depth of 3.94 m and a water velocity of 0.54 m/s, supporting the needs of larger fish species. Meanwhile, the Petuang River's optimum discharge was 0.08 m³/s, with a depth of 0.4 m and a water velocity of 0.04 m/s, which could only accommodate small fish species. These low-flow values, with an error margin of less than 20%, were used as inputs in the low-flow analysis. The study highlights the importance of E-Flow in maintaining river health. This holistic assessment, based on Integrated Water Resources Management (IWRM), supports sustainable ecosystem management using green physical structures to optimize environmental flow.
Abd Wahab N., Kamarudin M.K.A., Muhammad Sukki F., Marcus Ata F., Breckwoldt A. and Rohalin W.M. (2025) Ecohydrological Indicators and Environmental Flow Assessment (EFA) in the Inlet and Outlet Reaches of the Kenyir Lake Basin, Malaysia. Malaysian Journal of Fundamental and Applied Sciences 21(4): 2492-2512. 10.11113/mjfas.v21n4.4224
@article{Abd Wahab2025,
Title = {Ecohydrological Indicators and Environmental Flow Assessment (EFA) in the Inlet and Outlet Reaches of the Kenyir Lake Basin, Malaysia},
Author = {Abd Wahab, Noorjima and Kamarudin, Mohd Khairul Amri and Muhammad Sukki, Firdaus and Marcus Ata, Frankie and Breckwoldt, Annette and Rohalin, Wan Marlin},
Editor = {},
Journal = {Malaysian Journal of Fundamental and Applied Sciences},
Year = {2025},
Pages = {2492-2512},
Volume = {21},
Doi = {10.11113/mjfas.v21n4.4224},
Abstract = {The balance of environmental flow in basin-maintained ecosystems is crucial for sustaining biodiversity and the environment. Maintaining optimal environmental flow in rivers ensures the sustainability of natural ecosystems. An Environmental Flow Assessment (EFA) was conducted in the Terengganu River (outlet) and Petuang River (inlet) to assess whether river flow is sufficient to support ecological and biodiversity needs. The study aimed to develop a hydrological-hydrodynamic model to determine Environmental Flow Values (E-Flow) and to use ecohydrological indicators for restoration and rehabilitation in the Kenyir Lake basin. Sampling was carried out during both the dry and normal seasons. Data were collected on hydrology (water level and river discharge), hydrodynamics (using XPSWMM software), and ecology (fish sampling and Length-Weight Relationship (LWR)). Three sampling stations were selected on each river, with the fish species Toman (Channa micropeltes), Sebarau (Hampala macrolepidota), and Belida (Chitala lopis) chosen as bioindicators. These species were selected based on their size (width, length, and weight), which indicates their tolerance to Environmental Flow Values. A 7Q20 low-flow analysis revealed that in the Terengganu River, the optimum discharge was 42.78 m³/s, with a depth of 3.94 m and a water velocity of 0.54 m/s, supporting the needs of larger fish species. Meanwhile, the Petuang River's optimum discharge was 0.08 m³/s, with a depth of 0.4 m and a water velocity of 0.04 m/s, which could only accommodate small fish species. These low-flow values, with an error margin of less than 20%, were used as inputs in the low-flow analysis. The study highlights the importance of E-Flow in maintaining river health. This holistic assessment, based on Integrated Water Resources Management (IWRM), supports sustainable ecosystem management using green physical structures to optimize environmental flow.},
}
TY - JOUR
AU - Abd Wahab, Noorjima
AU - Kamarudin, Mohd Khairul Amri
AU - Muhammad Sukki, Firdaus
AU - Marcus Ata, Frankie
AU - Breckwoldt, Annette
AU - Rohalin, Wan Marlin
TI - Ecohydrological Indicators and Environmental Flow Assessment (EFA) in the Inlet and Outlet Reaches of the Kenyir Lake Basin, Malaysia
T2 - Malaysian Journal of Fundamental and Applied Sciences
PY - 2025
SP - 2492-2512
VL - 21
DO - 10.11113/mjfas.v21n4.4224
AB - The balance of environmental flow in basin-maintained ecosystems is crucial for sustaining biodiversity and the environment. Maintaining optimal environmental flow in rivers ensures the sustainability of natural ecosystems. An Environmental Flow Assessment (EFA) was conducted in the Terengganu River (outlet) and Petuang River (inlet) to assess whether river flow is sufficient to support ecological and biodiversity needs. The study aimed to develop a hydrological-hydrodynamic model to determine Environmental Flow Values (E-Flow) and to use ecohydrological indicators for restoration and rehabilitation in the Kenyir Lake basin. Sampling was carried out during both the dry and normal seasons. Data were collected on hydrology (water level and river discharge), hydrodynamics (using XPSWMM software), and ecology (fish sampling and Length-Weight Relationship (LWR)). Three sampling stations were selected on each river, with the fish species Toman (Channa micropeltes), Sebarau (Hampala macrolepidota), and Belida (Chitala lopis) chosen as bioindicators. These species were selected based on their size (width, length, and weight), which indicates their tolerance to Environmental Flow Values. A 7Q20 low-flow analysis revealed that in the Terengganu River, the optimum discharge was 42.78 m³/s, with a depth of 3.94 m and a water velocity of 0.54 m/s, supporting the needs of larger fish species. Meanwhile, the Petuang River's optimum discharge was 0.08 m³/s, with a depth of 0.4 m and a water velocity of 0.04 m/s, which could only accommodate small fish species. These low-flow values, with an error margin of less than 20%, were used as inputs in the low-flow analysis. The study highlights the importance of E-Flow in maintaining river health. This holistic assessment, based on Integrated Water Resources Management (IWRM), supports sustainable ecosystem management using green physical structures to optimize environmental flow.
ER -
