Author(s): Fang Yenn Teo, Md. Nasir Md. Noh, Aminuddin Ab. Ghani, Nor Azazi Zakaria, Chun Kiat Chang
Linked Author(s): Fang Yenn Teo
Keywords: River sand mining capacity, river morphology, hydraulic and sediment transport, replenishment rate
Abstract: In recent years, urbanisation and land development have led to an increase in river sand mining activities. These activities have given rise to various problems including: river bank erosion, river bed degradation, river buffer zone encroachment and deterioration of river water quality. Excessive removal of sand may significantly distort the natural equilibrium of a river system. Thus, it is important to further investigate on the river sand mining capacity as recommendations for long-term management of sand mining activities. This paper therefore presents a study that includes the assessment of the river morphology, hydraulic and sediment transport modelling, which covers three rivers with different levels of sand mining activities in Malaysia i. e. Muda River, Langat River and Kurau River. Field works on selected sites of the three rivers are made to assess the capacity of the rivers to convey both water and sediment. Data collection on bed material is made to identify the physical characteristics of sediment in terms of river response to erosion and deposition. A detailed sediment transport analysis is conducted to determine the suitability of existing sediment transport equations for use in the selected sediment transport models. Through the analysis, it is found that Yang and Engelund-Hansen equations are able to predict the trend of sediment transport for these three rivers. Hydraulic and sediment transport modelling study are also carried out to determine possible locations of deposition along the rivers. The depth and volume of deposition will in turn determine the viability of sand extraction taking into account the ability of the rivers to replenish the sediment. The findings of this study have provided a proposal on the minimum and maximum levels of sand extraction for each river, and it is also an invaluable planning and management tool for authorities to make effective and timely decisions on sand mining applications and operations in Malaysia
Year: 2017