ENVIRONMENTAL FLOW ANALYSIS FOR WATER RESOURCES MANAGEMENT GUIDELINE IN MALAYSIA
Management of environmental flow is useful to sustain the freshwater environment. In Malaysia, study on environmental flow characteristics of rivers is still lacking. In closing the research gap, this study proposes hydrological method for the evaluation of environmental flow characteristics of river basins in Malaysia. It is noted that the estimation of environmental flow in this study is based on hydrological method proposed by World Wide Fund for Nature (WWF), which is lack of biological basis. A total of eight river basins, which are six in Peninsular Malaysia and one each in Sabah and Sarawak were selected as the study sites. Analysis of annual water demand, annual runoff, water exploitation index, maximum (flood) flow, minimum 1-day low flow, minimum 7-day low flow, flow duration curve, intra-inter annual flow, hydrological condition, environmental flow allocation, flood regimes, and environmental water reserve was carried out. Based on the water exploitation indexes, the rivers that fall under severe stress were Sg. Muda, Sg. Johor, and Sg. Selangor; not stress for Sg. Kelantan, Sg. Pahang, Sg. Padas, and Sg. Sadong; low stress for Sg. Linggi. It was also found that the flow values for each flow category (very dry, dry, average and wet) are unique for each catchment and also vary with the month of the year. The study has proposed the range of flow for environmental water allocations under Eflow class A (very good ecological condition), Eflow class B (good ecological condition), Eflow class C (medium ecological condition), and Eflow class D (deficient ecological condition) categories. Moreover, this study also successfully estimated the flood regime and water reserve for all selected river basins.
Authors
Abstract
Management of environmental flow is useful to sustain the freshwater environment. In Malaysia, study on environmental flow characteristics of rivers is still lacking. In closing the research gap, this study proposes hydrological method for the evaluation of environmental flow characteristics of river basins in Malaysia. It is noted that the estimation of environmental flow in this study is based on hydrological method proposed by World Wide Fund for Nature (WWF), which is lack of biological basis. A total of eight river basins, which are six in Peninsular Malaysia and one each in Sabah and Sarawak were selected as the study sites. Analysis of annual water demand, annual runoff, water exploitation index, maximum (flood) flow, minimum 1-day low flow, minimum 7-day low flow, flow duration curve, intra-inter annual flow, hydrological condition, environmental flow allocation, flood regimes, and environmental water reserve was carried out. Based on the water exploitation indexes, the rivers that fall under severe stress were Sg. Muda, Sg. Johor, and Sg. Selangor; not stress for Sg. Kelantan, Sg. Pahang, Sg. Padas, and Sg. Sadong; low stress for Sg. Linggi. It was also found that the flow values for each flow category (very dry, dry, average and wet) are unique for each catchment and also vary with the month of the year. The study has proposed the range of flow for environmental water allocations under Eflow class A (very good ecological condition), Eflow class B (good ecological condition), Eflow class C (medium ecological condition), and Eflow class D (deficient ecological condition) categories. Moreover, this study also successfully estimated the flood regime and water reserve for all selected river basins.
Citation
Mohd Zaki Mat Amin, Noor Hisham Ab Ghani, Thian Siaw Yin, Zulkifli Yusop, Achmad Syafiuddin. 2021. ENVIRONMENTAL FLOW ANALYSIS FOR WATER RESOURCES MANAGEMENT GUIDELINE IN MALAYSIA. Digital NAHRIM Publication Repository.